Boeing hasn’t hit bottom yet. Neither have suppliers.

By Scott Hamilton


Jan. 15, 2020, © Leeham News: The extent of the damage to Boeing from the 737 MAX crisis still is unfolding.

Billions of dollars in new costs and charges are expected to be announced on the 2019 earnings release and call, Jan. 29.

But the long-term effects, only surmised until now, are beginning to become evident following information obtained by LNA from multiple sources.

  • Restarting production will be at a low initial monthly rate.
  •  Ramp to previously targeted 57/mo likely lags by three years.
  • The impact on suppliers will be profound.
  • Impact on employee retention is unknown.
  • 737 backlog delivery schedule will require major adjustments.
  • Airbus stands to benefit from Boeing’s extended lower production rate.
  • New airplane years away—even as it’s needed for Boeing’s future.
  • Lower 737 production rate reduces cash flow; 787 rate reduction will hurt, too.

Boeing hasn’t hit bottom yet. The worst is yet to come for suppliers.

Restarting Production

No date has been set for Boeing to restart MAX production. It was suspended in part because Boeing was about out of room to store new airplanes.

Since then, the Federal Aviation Administration gave Boeing approval to begin storing MAXes in Victorville (CA). No work or rework on the planes will be permitted under the current agreement.

But will this prompt Boeing to restart production sooner than later?

Based on available information, this doesn’t appear so. While Boeing hasn’t officially given any direction to the supply chain, information obtained by LNA indicates production will be suspended at least through February. Boeing hopes for a mid-February restart.

FAA recertification appears unlikely next month. Whether it comes in March remains a question.

Production rates

When Boeing restarts production, it won’t be turning a key and resuming rate 42/mo, which was in place when production shut down this month.

Based on available information, the initial production rate will be between 10-15 MAXes per month. The return to rate 42 likely won’t occur until 2021. Achieving rate 57/mo, which was the goal by the end of 2019, now likely won’t occur until late 2022 at the earliest.

This is one of dozens of scenarios Boeing has gamed out. It’s the one that, at the moment, stands out. This, like so many other things, could change.

Why so slow and so long?

Boeing has about 400 MAXes that have been produced and which are in storage in Washington State and San Antonio (TX). When it announced production would be suspended, it also announced that delivering these airplanes will take priority.

Boeing never announced how many of these new airplanes could be processed. LNA’s report yesterday details that the delivery rate may be slower than initially planned.

Also, Spirit Aerosystems now has more than 100 fuselages it built in storage that Boeing has to work through.

Restarting the supply chain is also a major undertaking.

Finally, given the mistrust that developed over the last year between the FAA and Boeing, it’s unclear how much oversight the FAA may exercise as Boeing prepares to restart production and the ramp-up of the production rate.

Impact on suppliers

The impact on suppliers is going to be profound.

Spirit Aerosystems last week announced it would lay off 2,800 employees for an indefinite period. It has no information from Boeing about the timing to restart production, nor at what rate.

The slow ramp-up means recalling employees, at Spirit, and any other supplier will be a gradual return to previous employment levels.

It will be challenging for Small suppliers to stay in business.

Employee retention

With a slow return to full production, the obvious question arises: how long will Boeing retain its 737 workers are on now on paid reassignment or paid leave?

In the greater Seattle area, around 10,000 Boeing jobs are associated with the 737. For every direct Boeing job, there are 3-4 indirect jobs. The longer the production halt continues, the greater the risk for these jobs.

A slow return to full production also places some of these jobs at risk.

Adjusting the skyline

Boeing had to make significant adjustments to its delivery skyline even before halting production. The chart shows the delivery stream in the skyline in July, three months into the grounding, shows the delivery stream at production rate 57. The latter was the rate Boeing intended to reach by the end of 2019.

Four hundred MAXes were 2019 deliveries. Deliveries from 2020 onward were all additional production delivery slots, at rate 57, that must be adjusted from the suspension and low-rate initial production, followed by a lower rate ramp-up.

The disruption to the airlines and lessors will be huge.

Airbus stands to gain

With production ramp-up being slow over an extended period, Airbus stands to make even greater inroads into market share than in the past.

Airbus wants to ramp up production of the A320 family beyond its current rate of 60 and announced a goal of 63/mo. It’s talked about going to 70/mo.

CFM announced it’s upping its delivery rate of the LEAP engine to Airbus following Boeing’s suspension of production. If Airbus can work the remaining supply chain (other than engines) to support rate 70, Airbus has a multi-year window to capture greater market share than the 55%-57% it now has (depending on the measuring point).

No new airplane for now

Boeing put on hold the development of a new airplane, whether it’s the New Midmarket Airplane (NMA) or Future Small Airplane (FSA).

Yet this is precisely the time developing a new airplane is needed.

The MAX will be a good airplane when it’s fixed and recertified. But it’s not good enough to compete with Airbus’ A321neo family. And the advantage Airbus will gain from the production halt, and slow ramp will put Boeing farther and farther behind.

A new airplane is needed for Boeing to be competitive again. (This was needed before the grounding, by the way.)

Reduced cash flow

Boeing’s cash flow will be reduced for years to come. The 737 accounted for about 40% of Boeing’s profits before it was grounded. The dramatic production decline will eat into this cash flow proportionately.

185 Comments on “Boeing hasn’t hit bottom yet. Neither have suppliers.

  1. I’m sure the money grubbing financial analyst they’ve put in charge will make sure dividends are paid at all costs and shares are repurchased on schedule, so have no fear…

    • If you take 10 a month as a starting point and the 52 a month they were making before the slowdown, its a possible 62 a month delivery rate.

      Some that are delivered just have to get the software upgraded.

      So it makes sense for the overall picture as you can only shorten the delivery process a bit at best and they will be adjusting to FAA and having to bring aircraft back from Moses Lake and San Antonio (what a treasure bu only if you are not stuck up on Puget Sound!)

      You do have to wonder why they did not go for Victorville earlier, takes a lot longer to get a plane from that god awful flat place in Texas (probably another cow town)

      A321 was kicking Boeing hard so this does not change.

      Leeham never felt the NMA was going to go so no change there per their assessment.

      Timeline might be long enough to nudge up Airbus share another 2 or 3 % but by the time Airbus Ramps up, Boeing should be back in full swing.

      The decision to change mfgs is 5 years down the road.

      Boeing should be making bold decisions and going for NMA or replacing the 737, not sitting on their hands.

  2. I am glad to see that Denis Muilenberg was so richly rewarded for his quite extraordinary strategic leadership

  3. Hopefully Boeing learns the lesson that you can’t cut costs on safety related systems without robust program-wide safety audits. If you keep removing bricks to save money, your structure will eventually fall, and it will cost you a lot more to rebuild it than if you had just kept those bricks in in the first place.

    • That is not how these people think or work.
      More like Asilidae.
      Don’t let yourself be hit by the resourced depleted collapsing building while leaving ( in the right moment ).

        • Scavenger culture.
          What counts is the extracted value.
          The value destroyed in the process does not count.

          buffalo extinction: hunted just for the skins.
          95% of the value a buffalo presented if fully used was destroyed.

  4. Amazing development, Boeing could support its 737MAX customers with cheap low MTOW derated thrust regional 787’s with the same max range as the 737MAX-8.
    When customers finally get their 737MAX’es take them back and upgrade to normal 787 MTOW and range and sell them on the market.
    Like for 3 grounded 737MAX you get one 787Re on cheap lease. Hence moving all 737MAX staff onto the 787 and make 1-2 737 FAL 787 FAL if they fit into Renton or tell them to commute to Everett.

    • Even on paper it looks so so I’m afraid. Somehow I can’t imagine Southwest flying 787s – new crews, new maintenance even on basic level, it will take a lot of time and money. Preparing derated 787 also will take time and money – desing, then certification. Boeing mantra is still RTS comes soon, however without public statements now. What the most suits airlines is postponing NGs retirement, extending leases, or wet lease of an aircraft. If they had NMA, even 767x, that would be other talk. But 787 is just to big, imo.

      • I agree that 787 is big, expensive and heavy for those missions but you can only offer what you have to AOG customers.
        I don’t know the exact certification time to paper derate the 787 to a much lower MTOW. Probably would its engines derate as well to the keyed-in low actual Take off weight. Boeing could tie it to a “Total care” program taking care of everything except pilots and cabin crew, (those can be sourced as well).

        • Your airline also needs to have access to the correct gate sizes. The 787 will require an E gate I believe. That is 2 sizes larger than the C gate a 737 requires. Southwest likely has no access to any such gates.

  5. What I do wonder:
    will the extra _production_ cost associated with the MAX grounding ( storage, reactivation, changes, … ) be pushed into the “deferred cost” basket as done on the 787 project?

    Afaics any potential for an Airbus gain will be matched by a neutralizing effort from the US political side. Table must be “leveled” !

    • Apropos this article and the above comment, it is a wonder to me that the stock price has held up so well. It is off only 25% from its (very brief) high in early 2019 and still twice the price of Jan. 1, 2017. Are the financial markets excessively optimistic or do they “know” something.

      If Boeing’s circumstances (both short term and for the next decade or more) are as bad as this article suggests (and FWIW I agree), then there should be some pain to come for the shareholders. Time will tell of course, but it seems like the market cap and the company’s circumstances are discordant.

  6. We can expect very bad news on January the 29th
    a new boss interest is always to settle completely all what was more or less swept under the carpet before his nomination.
    – obviously a lot of additionnal red ink for the MAX 6Bn? 8Bn? more???
    – do not forget the 787 deferred accounts, wide body orders will be on the soft side for quite some time, and a biggish chinese order -if it materializes- will not be enough to prevent going down to 10/month. That means 6 to 10 Bn from the deferred accounts should be charged.
    – 777X developpment will cost more, its certification will need more time, expect a couple of Bn on this issue
    floods of red ink!
    and quite a few quarters of cash burn…

    • Hi

      Could you elaborate on why there should be a charge of 6-8Bn please?

      • From the Seattle times dated january 13th
        The bungling of the MAX crisis cost former CEO Dennis Muilenburg his job, and the bad news is far from over: Boeing is expected to reveal one of the largest writedowns in its history this month along with fourth-quarter results.

        “The company has a unique opportunity to get all the bad news on the table now,” said Jim Schrager, professor of entrepreneurship and strategy at the University of Chicago’s Booth School of Business. “It’s time to get this right and make the turnaround.”

        The accounting charge is likely to be in the $6 billion range, said Cowen & Co. analyst Cai von Rumohr, as Boeing balloons its reserve to compensate airlines to $12 billion. That’s another risk for investors, who have taken a hit from the crisis while dodging a full-fledged meltdown.

        • Thanks, I didn’t realise that was the magnitude we were talking about

          • it could be a lot worse!!!
            from aviation week

            Boeing stakeholders may find out more information about the costs of the 737 MAX fiasco during the company’s Jan. 29 report on 2019 financial results. While Boeing previously identified $5.6 billion in pretax customer compensation for aircraft operators, and added $3.6 billion to the 737’s program accounting block-cost, financial analysts, consultants and others see those figures as just a beginning.

            For starters, new costs such as flight simulator training, already are known but have yet to be publicly explained by Boeing. “Simulator training likely will add almost $5 billion to the cost of the grounding, using Southwest [Airlines] as a benchmark for the 4,543 [737 MAXs] in backlog at the third quarter of 2019 and the 385 in existing fleets, all of which were sold before the grounding,” Bloomberg analysts George Ferguson and Francois Duflot said Jan. 9.

            Similarly, aviation economist Chris Tarry said in a new report this month that Boeing faced a bill of more than $8 billion in compensation for airlines alone. In December, when Boeing announced the MAX production halt, Jefferies analysts Sheila Kahyaoglu and Greg Konrad surmised that customer concessions alone could reach $11.7 through the end of the first quarter of 2020.

            Then there are costs for carrying the inventory of roughly 400 MAXs parked by Boeing, as well as potential further changes to the 3,100-aircraft program accounting block basis. The Jefferies team said the ongoing delay in aircraft certification and change in production cadence could generate another $3.6 billion charge to Boeing’s earnings.

            Several industry analysts and consultants also believe Boeing will have to support its supply chain financially to some degree, so providers are able to ramp-up MAX production rates again as efficiently as possible. Moody’s Investors Service analysts said in a Jan. 10 report they expect Boeing to be supportive of suppliers on an individual, as-needed basis. But costs were not quantifiable yet.

            “There will be a particular focus on weakly positioned companies and/or those that have sole-sourced products,” Moody’s suggested. “The exact nature of any support arrangements could take multiple forms, including certain suppliers maintaining some level of production (and continuing to get paid), advance payments, more favorable (i.e., quicker) payment terms, inventory assumption and/or the facilitation of access to vendor financing.”

            Other costs loom, too, such as final compensation to victims’ families through legal action. Similarly, shareholder lawsuits may emerge that require spending to litigate. Last but not least, there will be additional costs from taking on more debt, which Boeing is expected to do rather than cut shareholder dividends.

            Altogether, it could take years before the full costs of the MAX debacle are known. In mid-October 2019—when Boeing still saw a MAX return to service before the end of last year—Bank of America Merrill Lynch analyst Ron Epstein already had expected it would not occur before the first quarter of 2020. He forecast costs for the 737 MAX to total $17.2 billion in 2019-23. On Jan. 16, Epstein told CNBC the total cost of the grounding could reach $20 billion—excluding any settlements from lawsuits from crash victims’ families—if the aircraft return by June or July.

  7. Boeing had been selling 787’s at low prices in the so called effort to kill the 330NEO, now those are being produced when BA needs the cash flow from the 787’s.

    It’s never nice to exploit the competitors situation but BA was never trying to be “nice” to AB. Is the 737MAX sorrows creating an opportunity for AB to sell A330NEO’s at very competitive prices, they do have the capacity to increase production of these?

    • Although it may sound tempting there is no suggestion that Boeing can be driven into business failure,firstly they still make money, secondly they are too big to fail politically. So why discount products when there is a finite demand to be satisfied and relatively limited opportunities for conquest sales. Instead AB should be rubbing its hands together anticipating a slightly more diffident pricing approach on the 787 going forward

      • Is Boeing making money? That is certainly very much a question of how you define “making”. Maybe they are making money in their accounting, but the cash-flow is in deep red numbers. And once the charges for the MAX incurred costs are booked, the balance sheet will look really, really ugly. So no, I wouldn’t say Boeing is making money.

        Are they too big to fall? Well, GM went chapter 11, and so did American Airlines, RollsRoyce, Leeman Brother and others. Maybe Boeing will be the biggest one yet. If the MAX is not re-certified by one or several of the more important regulators, that should do it for them. And that is not a very unlikely scenario.

        • All those industries were in sever economic distress.

          Boeing is stressed, but it is not a failing industry, it has a good split between defense and commercial aircraft.

          It has all the ability needed to overcome this.

          It will be interesting to see if management limps it along or cleans it up as it can continue to limp for a long time.

          One thing I would do is write off all the build up financial impacts , 777, 787 and MAX right now. Take the hit and start over. I don’t know if they can elect to do that under deferred accounting or if they would have to change the accounting. Either way time to do it.

          I think we will have a vastly better idea 4 months.

          Trying to assess Boeing is like half way through a horse race, you don’t know what is going to happen in the last furlong as it were.

          • “It has all the ability needed to overcome this.”

            Well, that is very much the question. I would not bet on it. And you should neither.

          • Sooner or latter Boeing will overcome it.

            It may be that it has to be so far gone as to require a Mullaly like intervention or they right the ship.

            I hope they right the ship, not for management sake but for the employees of Boeing and its suppliers.

            For now I am in wait and see mode.

            This is much like trying to shoot a horsemen going full gallop at 90 deg to you with a bow and arrow.

            Too many factors in play to call the shot.

            Anyone that thinks they can should try Vegas and see how they do!

      • You hit the nail on the head. Projecting forward, (an oxymoron), it is an election year as well a nationalistic approach to the problem. Classic u.s. against them. Still a coin flip, and EASA holds the key to certification , IMO.

        • “.. EASA holds the key to certification ..”

          in a way YES. But FAA/Boeing has to create the keyhole ( and lock ) first.
          i.e. they have to fix the “deviation from theory” in their setup.

    • Sure they have, space and people from ending A380 programme. The question is how long this would take, especially given the less than expected production run-up of the A321.

      They could have even offered an A380Regional for 853 pax = 5 MAXes at once. Wow, that was ironic!

  8. Restart MAX production in February ??? For now sounds like a new itineration of game of giving RTS date.

    • >Restart MAX production in February ??? For now sounds like a new itineration of game of giving RTS date.

      Yeah, can I get some odds on that one?

  9. Sad observations, specially for those directly involved.

    And even in here, a lot of positive assumptions.
    – Compensations to airlines must be significant
    – The current 4000 MAX order book is solid..isn’t it?
    – Stock value is a (the?) pillar of the company, anticipate reality corrections
    – silence around 777x certification process, T-X will cost billions for years.
    – The Embraer deal is not closed. What if Embraer / Brasil got second thoughts & starts dating better wedding partners.

    David Calhoun has a hellof a challenge. Draconic changes and blunt honesty might be required to prevent things going really south..

    • “– The current 4000 MAX order book is solid..isn’t it?”

      Define ‘solid’.

      Boeing booked -120 “contractual changes” plus -132 ASC 606 adjustments for the 737 in 2019. There are quite a few literal white tail MAXes in storage for leasing companies who don’t apparently have customers for those planes.

      • By rather regularly expressed opinion Boeing invariably had sold to the “better” customers !
        After the GFC my impression was that Airbus put more effort in accommodating their customers by rearranging the delivery flow.

  10. The combined pressure upon Boeing to complete delivery of stored new aircraft + readjust upstream suppliers’/FAL throughputs + return-to-flight of grounded units worldwide is bound to weaken quality control. An increasing number of quality control incidents are likely to be reported, impairing operator/customer reliance in the MAX as a safe product, which again will backfire upon MAX sales … with a resulting negative impact – finally – upon share quotations. It appears that Boeing Board strategists’ obsessive fixation upon shareholder value may have taken BCA astray ?

  11. This news must put pressure on AB to fast forward the ramp of the A220 and also development of the 500. I appreciate the issues of cost and legacy suppliers but this is a once in a lifetime opportunity to gain 15% market share before it gets messy with C919, NSA, MC21 etc

    • I don’t see any way that C919 and MC-21 become challengers on a global scale. In their ‘domestic’ (captive) markets, sure, but not World wide.

      • The 919 is not certified, it literately cannot be sold outside of China (Zimbabwe may not even take it)

        The MC-21 will be certified, but you have the track record of the Super Jet and Russia arms sales where they have a failure to support product.

        Far better the MAX you can get soon that a pie in the sky that is going to be a stone around your neck.

    • I’m sure Airbus have been looking at options on this since late 18. And agreed.

    • I have always been “going on” about an A320Plus, think it sill has merit/s but it will be head on with the C919 and MC21-3 (and 737-8) in future.

      AB can capture a very significant portion of the market with the A220-300/”500″ and variants of the A321 and guess where we we will see their SA focus in short to medium term.

      With Boeing fighting the “MAX Wars” nobody talks about the NMA or MoM anymore. As time is progressing is becoming clear in my mind that airlines will need a “small” TA in the next 10 years.

      Roughly 250-280 pax, 5500Nm range, OEW around 100T, ~55Klb engines. lets hope we see action on that front in the not to distant future. If RR could come up with a “small” UF-engine things could be interesting.

  12. @Scott

    Any news on “pickle force” for NGs? (=workforce needed to fix pickle forks). Any advance?

  13. The article is still far too optimistic.

    To add one more to the list. Most airlines have bought the MAX by taking out a loan using the airplane as collateral. It works, provided there is a secondary market that is willing to pay a good sum for a used MAX. Will there be a good secondary market. No. What will the ceditors do? Either withdraw the credit or demand a significant price reduction from Boeing. Boeing isn’t going to get $50million for a MAX. They won’t get $40 million, either.

    Will Airbus go to 70 A320/month and 20 A220/month. Of course they will. The A380 line will shut in the latter part of this year. A spanking new A321 line will replace it. Not official yet, but will be. Will the supply chain cope. Yes. Airbus issue is the line itself. The engines will now come.

    “The MAX will be a good airplane when it’s fixed and recertified”.

    I do like the optimism. But I think it’s not warranted.

    No new FSA launch for years. Are Boeing just mad? Do they need to see a trick cyclist?

    I think it’s all down to the optimism we witness from the Boeing lobby. According to the Boeing lobby, the MAX will rise from the ashes, conquer all, and become a roaring success. I hope the Boeing lobby know what they are doing. To me your digging Boeing’s grave.

    Boeing need to start a FSA, now.

    • Quite (re the financing aspect). I don’t know what effect the stigma attached to a MAX will have on residuals but any near term launch of a replacement design (I’d say this must be certain, but then reality doesn’t seem to be something Boeing’s top level are as well connected to as they ought to be) must hit them significantly.

      I think now is a bit early for any FSA launch, despite what they actually need. I just don’t see Boeing having the resources required to do it properly until either the MAX is OK’d and in a reliable return ramp or the 777X is likewise. Even then, surely there is a very significant decision to be made whether it gets done out of Seattle or instead out of Brazil, so that takeover needs clearing up first. And finally there would be the taint if Calhoun is still in charge and/or there is no publicly seen genuine change of culture when a launch happens. Otherwise there can always be a suspicion of below acceptable engineering practices in the new model’s development.

      • I find the notion that you define the discussion and provide the answer with zero facts.

        Clearly the MAX value will be normal if its a proved to fly again.

        As the sun is defective, it will not come up tomorrow.

        Well clearly the Sun nor the MAX is defective, despite the fact both have issues. The sun has hissy fits and sun spots and warms and cools.

        The MAX had MCAS (fixed).

        The facts don’t support a no support proposition.

        • Your wording seems garbled (a missed edit?) but it seems you are stating there are zero facts to back up the assertion that a replacement model airliner negatively impacts residuals and therefore ultimately the cost to airlines. Maybe there are instances when this isn’t the case but all the data I’ve seen indicates that it does. Any airline or lessor who chose to acquire the MAX before the debacle will have done so on costs that assumed a replacement model would not arrive before early next decade (if I remember discussions on Leeham and elsewhere over the past few years correctly). Should a replacement now be launched near term those costs will change if MAX residuals change. Or is there something you think is incorrect in this?

          • I agree with your thinking there. If there is even a hint of a drop in residuals then the lender ‘might have’ to increase their share of the plane value. Some airlines may have loan portfolio spread over older planes that currently are worth more due to ‘shortage’. Other airlines may be in a weaker position financially and small existing fleet and be more exposed. Those airlines that have their borrowing all locked in will be better than those who havent. All those undelivered 737s are especially vulnerable to not having their deals locked in.
            Another thing to consider is that Boeing is not going to be in a financial position to ‘support’ some of those fast expanding airlines with big orders anymore, especially if financing is harder. Maybe the reduced production rate will solve those possible dropped orders, but the ‘visuals’ of a swathe of those cancellations wont be nice.

        • “”The MAX had MCAS (fixed).””

          MCAS is not fixed yet and
          it’s very questionable if MCAS will ever be allowed on the MAX.
          I can’t imagine a software fix only will cure the MAX issues.
          EASA will detect that MCAS is a stall system, then Boeing has to decide how regulations could be met.
          There also might be hardware changes which don’t have to do with the “happy nose”.

          • Look it up . You are completely wrong, as it a mix of software AND input from more than AoA/airspeed sensor

          • Duke,
            MCAS isn’t certified yet.
            We are still at the audit stage, either the audit is still in the works or the audit is complete and FAA/EASA is checking it.
            After that flight testing will uncover what MCAS is (I’m expecting a stall system).

    • I’ve been thinking. There are a whole lot of assumptions out there about Boeing’s ability to produce a solid and successful FSA. The 787 seemed to take a whole lot more from them than one would imagine. Maybe more than greed led to the Max. Maybe they just can’t do better anymore. Just thinking

  14. Here is a dark horse. Rolls-Royce Ultrafan runs in 2021. If the numbers do come back as predicted, Ultrafan could become an engine option on the A320/A321

    • That would probably be easy for Boeing.

      If, however, UltraFan runs on the 350-900, 350-1000, a new 80m stretch 350-1100 (pushing the 777X out of the market) and the 330-900 (Pushing the 787 out of the market), while Boeing cannot respond, then Airbus would be superior in all segments of the market.

      But it won’t happen. The UltraFan may “run” in the next few years, but it will take 5 to (rather) 10 years to make it an engine mature enough to use it in daily commercial service.

    • Most likely PWA and CFMI have exclusivity on the present neo’s. The dark horse is the A322 or A321neo++. So a 40k Ultrafan might come after the A350neo Ultrafan.

      • Why should Airbus have granted exclusivity on the A320? Nah, PWA and CfM are more than happy to get their share, but other than that?
        RR did acquire a second test bed 747. That makes sense only when they develop the smaller and the larger version of the Ultrafan in parallel. And why not. Parallel developments can have large benefits, as the two teams can learn from each other, identical materials and production methods or even infrastructure can be used. Plus you have twice the chances of winning sales.

        • We will see, but a 40k narowbody Engine has an Engine core of similar size as a 65-70k widebody Engine that does not need the same cyclic Life on wing. Think the 757 RB211-535 got the RB211-22 core Engine initially and it proved tobe a good move as the hot PW2000 had problems, so RR might do that trick again keeping the Ultrafan core Engine the same for both A350neo, 787-10 and an A322 class Aircraft. Boeing might ask for a 37k version for one of its high and slender trussed wing design?

          • Thanks for the link. That’s looking like a really interesting concept. Plenty of room for large engines, by the way 🙂

            The biggest problem with this “moonshot” is that it’s truly a new aircraft which will take a long to time get into service. But it could be one part of a two-pronged strategy: One “quick” aluminum/FBW/conventional single aisle, and this being the innovative/CFRP/ultra-efficient long shot. It needs no mention that both planes should have enough room for the next generation engines.

            I’d love to know what Boeing and Airbus really think of open rotor systems.

    • RR have hinted they want to get into the small engine market, and it’d make sense if it was Ultrafan. And they’d quite happily sell to Boeing as well as Airbus.

      RR’s various developments are said to be coming along nicely, in which case GE had better watch out. A geared Ultrafan on A350, 787 and A330 would be very hard to beat.

  15. Here is an interesting question. Will this advantage COMAC and Irkut? Will it send the industry into a tailspin of rotating losses as 4 competitors compete aggressively?

    • I am pretty sure that both Comac and Yak will have considerable difficulties in industrialising the ramp up even if their certification plans are achieved. In volume terms they will be an irritant and no more.

      • 919 is not certified and has no path to do so.

        Russians can and will certify MC-21, see the fate of the Superjet.

        Russia is incapable of global support.

  16. Any indication to what extent, if any, Boeing is putting in place mitigation for the crucial small suppliers that lack the resources to cushion the pause? Would seem to me to be beyond stupid of Boeing not to set aside the capital needed to do this, even if it means continuing some level of production from them and storing the parts (I’m guessing the parts would all be small and mobile enough that plenty fo warehouses would be able to take them). Then again, Stupid seems like Boeing’s new middle name.

    • I think they will do that as soon as they have some certainty from the regulators. Spirit also alluded to this in their statements, that as long as the climate is uncertain, there is not a business case for further production.

      That’s really unfortunate. We have a situation where if the regulators try to provide some certainty, it creates the appearance of being responsive to Boeing. So the goal now is no timetable, when a timetable of some sort is what is needed for business planning.

      TW had suggested a regulator periodic update web site to indicate task progress or new tasks undertaken, but not results. Also they could create a projected schedule with the understanding that it might slip (no one understands slippage better than the aircraft industry). That would give businesses at least some idea of what to expect.

      • Except that now, while the climate is uncertain, is exactly when these small(er) suppliers need the help. Once there is some clarity/certainty their access to finance to help them through increases.

        Absolutely agree with the need for all suppliers to be kept in the loop re regulatory progress and status. I’m actually surprised that this doesn’t exist, if it doesn’t.

  17. Incidentally, how about Håkan Buskhe for a senior role at Boeing? I don’t know if he brings any baggage but he has plenty of CEO level exprience at Boeing’s defence partner Saab, an engineering background, IT experience, must by necessity have an international outlook, and has just retired from Saab and yet is only mid 50s.

    • I am willing to look at anyone who can bring a new can do and will do the right way corporate culture to Boeing.

  18. I don’t see any way that C919 and MC-21 become challengers on a global scale. In their ‘domestic’ (captive) markets, sure, but not World wide.

    • We might be surprised in 2022 when probably C919 will enter to market. Chineses if want to do something in good quality, sure they can, and have almost unrestricted financial backing.

    • Russia knows how to design aircraft, China knows how to build things. A JV allowing Chinese production of the MC-21 could be a problem for both BA & AB.

      • Yep,an interesting marriage that can’t be completely far fetched given the Craic venture. For that to happen China would need the C919 to have major, almost unsurpassable, certification issues. That is a possibility in my view. An MC21 is in the space of the A321 in cabin width and stretch ability. A strong contender.

        • 919 cert is indeed going slowely & I can’t see it selling in developed markets even if they got FAA certification at some point. MC-21 has a chance IF they can sort out support & spairs, a big if, but it could be done. Make a better offer for EMB if BA don’t get it?

      • It’s hard to see anything that Russia and China do though the lens of ideology that blocks my vision. I am not sure, but Russia has always produced some of the best and most resourceful aeronautical engineers in the world. As for China and reliability: I challenge most people on this site to find something in their environment that they constantly rely on to work that’s not made in China. Old stereotypes die hard. But whatever emerges will have to be a be alone to a cold hard fact and not ideology or spin.

        • China can do quality if they want to, the biggest problem will be trust between the 2 parties.

          • The biggest problem will be continuity in support.
            Are those one off airplanes or something of a bigger scale. If that so they should have been moving faster.

  19. Boeing should admit defeat and get the supply chain underway. Simple enough: RESTART the NG production! And offer them to airlines at a lower price than A320NEOs so the fuel differential is balanced. Southwest would take new NGs right now in a heartbeat.

    And at the same time launch the NSA/NMA – basically a re-engined 757 to minimize cost and time and provide a real A321XLR competitor.

    • That does not float.

      The NG isn’t cheaper to build than the MAX.
      I don’t think that Boeing got/gets “stinking rich” selling MAX frames. if MAX frames are not merchandizeable they are sitting
      on $25..35 billion urnrecoverable scrap. ( What parts are really the same on MAX and NG. so much fiddling under the hood. How cheap would an NG have to be to be taken up by customers? ( and they all were promised MAX efficiency not the NG fuel sucker 🙂

  20. Does anybody know if the MOU from IAG for 200 MAX is confirmed? I wonder how Willie Walch got mad critizising Airbus for delays of 2-3 months and being completely possitive about Boeing. Now that the delays of the MAX is expected to reach the 2-3 years mark does IAG still be so possitive about the MAX?

    • Nothing happened from Paris Airshow in 06/2019. It’s still MOU, nothing finalised. Total silence.

      • Also Willie Walsh will retire soon. Therefore I expect no decision by him for new aircraft.

  21. The MAX may will be the safest plane never to fly. By the time all the costs are booked to get the plane back in the sky, the bean counters may well say that it just isn’t worth getting them back into the air. If they lose 35% of the order backlog the cost of each MAX could well be the same as the Dreamliner! Then add cost and time to develop a new plane? I’d say Boeing will need at least $78 billion of capital expenditure. Isn’t that the same amount they paid out to shareholders?

    Haven’t even spoken about the hazy future of the Dreamliner (falling sales and two production lines) or the disaster that is the 777X (not as bad as the A380 as it can get some cargo orders).

    If a script was being circulated in Hollywood about the Boeing saga, even if Tom Hanks was on board, no one would buy it. And yet here we are….

    • “hazy future of the Dreamliner (falling sales and two production lines) or the disaster that is the 777X”

      All widebodies have hazy future these years, not only 787.

      777x is not a disaster, has his odds of course, but surely will be more popular then A380

    • “If a script was being circulated in Hollywood about the Boeing saga, even if Tom Hanks was on board, no one would buy it.” 🙂

    • Your match and logic is off.

      You have made aircraft that just need to be delivered. Its an asset you can’t write off or you pay big bucks on top of big bucks.

      You do not even have an approved design for an NMA and that is 5 years off.

      The 757 is never coming back any more than the Model T is so just accept that. It does not mfg out as needed.

      • Asset value depends on being suitable for delivery.
        Delivery depends on certification.
        If certification is unreachable the asset value contracts to scrap value.
        Additionally “time” takes its toll. A year old weathered airframe is no longer a “new plane”.

  22. It is a pity Lockheed departed commercial aviation, 2 major OEMs means there are too many eggs in too few baskets. Could the MAX grounding have been the trigger for the EU’s pausing the BA/EMB tie up?

    • Would you like to revisit the C5?

      How about the F-35?

      You might want to reconsider Lockheed and disconnect from its well founded path to the flopping turkey it is today.

      • Well, let’s just say no other major US OEM? Apart from AB, which just goes to reinforce the duopoly.

        • What people think but don’t dare to ask. If Raytheon Collins, Embraer and Spirit create a JV, you have equipment, builder and integrator roles. The supply chain would be willing to invest in a third credible Western integrator.

          Taking a foreign design as starting point worked before, T-X, MH-139, KC-390.. Adopting and re equiping, re certifying e.g. the carbon wing, GTF, container capable MC-21 might save a few years.

  23. There’s a lot of assumption that the MAX can be re-certified with just a software fix. Boeing wasn’t totally upfront with the FAA in the original certification of the MAX After Two accidents, the FAA is looking at the 737 design more carefully. It’s had quite a few changes since it’s original type certification. Foreign regulators are seriously questioning the FAA’s certification standards for approval. Just one area for example, that an Engineer has raised..

    I’ve seen very little, if any coverage of this question about the current jackscrew on 737-MAX’s. Should the 737, with all of it’s changes over the years, be brought up to current regulatory standards? How many incremental changes (and some are huge), does it take to trigger a total recertification of an aircraft design?
    from WikiPedia
    Sylvain Alarie and Gilles Primeau, experts on the horizontal stabilizers, observed anomalies in the data from the aircraft data recorders: a progressive shift of 0.2 degrees of the horizontal stabilizer, before the crash. “It may not seem like much, but it is an order of magnitude higher than what is normally allowed when designing systems like these”, says Gilles Primeau. They say that the movements are easily observable, and disallowed according to Regulation 395A

    Since its original design, the 737 has become 61% heavier, 24% longer, 40% wider, and its engines twice as powerful. These experts are concerned that the loads on the jack screw have potentially increased since the creation of the 737. By regulations, the controls must be designed for 125% of the foreseeable loads. These experts have raised concerns about the motors possibly overheating in April 2019

    the orginal link in French

    The translated link in English

    A youtube video by the same Engineer.
    In French
    (turn on Closed captioning, then under settings turn on auto-translate to English or any other language)

    • I agree, as usual.

      I do think I know what’s wrong. I first proposed the theory sometime ago. But my numbers were off. They were off because the numbers in public were off. To be clear, we were told that the default setting of the stabiliser was +2.6°. It’s closer to -2.6°. The minus sign is important.

      The Lion Air crash report does state the actual numbers but the actual numbers don’t invalidate my theory.

      So to return to the theory. The elevators have problems when the stabiliser – leading edge – is positioned at a positive AoA to the airflow. Especially when there is high dynamic pressure.

      The theory is borne out by the Lion Air crash report. MCAS is all about moving the stabiliser leading edge up. There can be only one reason for that. To produce an upward force at the tail to bring the nose down.

      Tails that produce lift are necessary if the lift of the wing is forward of the CoG. With regard to the lift of the wing, I include the nacelle.

      Why are they not using the elevators to bring the nose down. Clearly the elevators don’t have sufficient authority.

      I also have a theory as to why the elevators son’t have sufficient authority. The short answer is the stabiliser is contesting the elevators. Not a good idea. Stabilisers must complement the elevators not contest them

      I’ll give more detail at a later date. I really do want to know what EASA is going to say about this.

      For those who don’t know. Typically tails produce a downward force in civilian airplanes. The reason is the lift of the wing is behind the CoG.

      But, early 20th century military airplanes used tails that produced an upward force because the lift of the wing was forward of the CoG. They were difficult to handle. Why? The nose always wanted to go up.

      So for decades the standard configuration is wing lift aft of the CoG. Then tail produce a downward force. But, modern military combat airplanes have returned to the opposite. Wing lift forward of the CoG. Tail producing lift. Why. It improves turn rate. But, modern military combat airplanes have all moving large stabilisers with whizz bang, high speed, servo actuators to address the handling difficulties experienced by early 20th airplanes.

      I’ll give more details on why I think the elevators are having problems another time. I want to know what EASA say.

      Please note, it’s still a theory. I’ll explain why at a later date. But look at the Lion Air crash report. MCAS is all about moving the stabiliser leading edge up to cause a positive AoA. Therefore to produce an upward force.

      • Philip, small correction, MCAS does not change the AoA, that is under the control of the pilot at all times, via the column and elevator. It only adds a linearizing force to the airframe and the control column at high AoA. This is why elevator authority should not be a problem, under the intended function of MCAS.

        If the AoA is high, that’s because the pilot has brought it there intentionally with the elevator. So again the elevator has sufficient authority. If the pilot lets go of the column, the elevator will return to neutral position and the aircraft will level out again, with or without MCAS, which is only needed when the pilot holds the column back.

        In the worst case of MCAS malfunction, where it uses its full authority of 2.5 degrees stabilizer deflection, and the pilot takes no corrective action for the stabilizer, the elevator still has sufficient authority to override, although with higher control forces. We saw that in the data from both accident flights, the pilots still had control at this stabilizer deflection.

        EASA has concerns about whether MCAS represents stall identification/prevention, and whether it would interfere with a pilot’s recovery from stall. We’ll have to wait for the test results to see.

        • Well, MCAS has to help the aircraft pass these tests.
          Part 25 Airworthiness standards:
          25.173 Static longitudinal stability.

          (c) The average gradient of the stable slope of the stick force versus speed curve may not be less than 1 pound for each 6 knots.
          25.175 Demonstration of static longitudinal stability.
          (1) Starting at a speed sufficiently above the stalling speed to ensure that a steady rate of speed reduction can be established, apply the longitudinal control so that the speed reduction does not exceed one knot per second until the airplane is stalled.
          (2) In addition, for turning flight stalls, apply the longitudinal control to achieve airspeed deceleration rates up to 3 knots per second.

          Now reading that I see a max deceleration of ‘one knot per sec’. But it doesn’t give a minimum deceleration. So in the case that during a test or not during a test, the pilot decides to go to no deceleration after MCAS kicks in, what happens? The stick force must be increased just for the aircraft to maintain constant velocity. Or if constant stick force is applied during the duration of MCAS, the aircraft accelerates. I would not call that ‘linear’, but that word does not seem to be required.
          MCAS does not appear to be a fine instrument dialed into the input of variations of stick force and finely adjusted outputs, but rather a cruder instrument with an input of a single trigger based on AOA that fulfills the requirement of an output of at least 1 lb per 6 knots of stick force in the two tests to stall.

          • Ted, MCAS deflection is based on lookup table of airspeed and altitude. From that table, it gets the best correction for the conditions, once triggered by high AoA. It tries to bring the stick forces within regulation. It lessens the slope of the gradient. But you are right that it isn’t a fine instrument. It’s a typical open-loop controller. Given an input, it apples a pre-determined correction for that input.

          • Also the no deceleration case, or the acceleration case, are the pilot either holding the high AoA steady, or using engine power to climb steeply while maintaining high AoA.

            In those cases MCAS will maintain its deflection and influence on control forces, as long as high AoA is maintained. Whether it has any other programming to account for speed or altitude changes while activated, I don’t know.

            The regulation tests don’t really address those scenarios because they don’t lead to stall. The stability criteria are meant to make sure the aircraft does not fly itself into stall.

        • Rob, If MCAS just activated a stick pusher to increase column force, then then AoA wouldn’t change, as the pilot would hold the column in the same place, just noticing more stick force. But, MCAS turns the trim wheel, which change the angle of attack of the horizontal stabilizers, pitching the plane down, changing the planes AoA, hopefully switching off MCAS when it lowers to a certain value, registered by the Alpha vane sensors. That’s the current design of MCAS as I understand it.

          • Richard, I think this confusion is were the problem lies. MCAS can use the stabilizer’s change in AoA, to apply a force to the airframe and column, without changing the aircraft AoA unless the column moves and the pilot wishes.

            This is what other forms of trim do. The idea there is to unload the elevator & column forces for the pilot, but have the pilot still be in control of AoA using the column and the elevator. This is possible because the changes in stabilizer position are small, and the resulting corrective forces are also small.

            MCAS does this in reverse, instead of unloading the elevator, it slightly loads it and the control column, so as to comply with the regulations. But the corrective forces are still small, and the pilot retains control of AoA via column & elevator motion, just as with ordinary trim.

            Using a stick pusher, but allowing no column or elevator motion, is the same as using the EFS to apply a force. It’s artificial in that there is no impact on the aircraft dynamics, only a false force applied to the pilot. That might satisfy the regulations, but would violate the spirit of them.

            The regulations assume that the stick represents actual aircraft conditions, with the exception of stall prevention where artificial force is added by EFS within the regulations.

          • Rob, The column moves the elevator. The trim wheel the stabilizer. Both control the tail of the planes force. I had an instructor demonstrate to me, flying a plane, takeoff to landing without touching the column. I was over correcting, and he wanted to make that point. He only used throttle, rudder and the trim wheel. I suppose in some sort of weird column jam this might be useful, but, I”m sure it’s not listed in any flight manual. The point is, he controlled the AoA, without the elevator. Entirely with the trim. I don’t know if this would work in a 737-simulator or not. The column force vs the tail force, is the issue. If you’re simply adding column force to abide by a regulation, or are you changing tail force to pitch the plane down, because of the added pitch up force of the engine nacelle lift etc. The added lift, either from a gust of wind, or the change in the aerodynamic lift of the plane at different AoA’s is what you’re trying to account for?

          • Richard, you can control aircraft pitch with the trim rather than with elevators. It’s been done before in emergencies where the elevator controls have failed. The intention of trim is not to control the AoA, but to relieve the pilot of the burden of excess forces or continuous adjustment.

            For MCAS the behavior is slightly different, it adds force rather than subtracts it from the pilot. But the intention is the same, a small correction that assists the pilot.

            Maybe it would help to imagine yourself as a manual MCAS. You’re flying the MAX in cruise and you pull back on the column to get an A0A of 12 degrees. You notice the column getting a little soft. So you reach down and give the trim wheels a nose-down tweak. This stiffens the column back to the expected force. And that’s it, your task as manual MCAS is done. Still flying at 12 degrees, still under column and elevator control. Nothing has changed except the stabilizer position (slightly) and the column force (slightly).

            That is MCAS 2.0, and as MCAS was always intended to be.

      • Lift on the tail is unstable.

        All the newer designs allow to reduce H-stab down force ( changing CoG(older) or CoL( recent) but not flipping it over to lift.
        The H-stab turns around the neutral elevators CoL of the H-stab. that is the axis that requires the least force to move the full assembly.
        Elevator deflection changes the CoL of the H-stab. now the jack-screw is loaded. unfortunately countering the move to a sane position.

        What position of the H-stab provides for zero lift/downforce? it is an inverted asymmetric profile.

        • Uwe, positive lift on the tail is what would be accomplished by an equivalent aerodynamic solution. So MCAS is just emulating that, but with an active algorithm for better control.

          The stabilizer is permitted to do both positive and negative lift on the tail, as part of its control function. That’s why it has a range of motion from 4 degrees positive lift to 14 degrees negative lift. The negative range is greater because some negative lift is always required for stable flight.

          The jackscrew is loaded at almost all times of flight, that should not be an issue at all. It’s designed for all combinations of elevator and stabilizer positions, as are the elevator controls, within the normal range of airspeeds. Elevator and stabilizer are designed to be independent. Whatever coupling occurs, should not be an impediment to operation of either.

          The maximum deflection of MCAS of 2.5 degrees should not substantially alter the elevator loading. We know that MCAS alters it slightly to get the right elevator control force in the column.

          The elevator is already in a strong nose-up position before MCAS engages and trims slightly nose-down. If the pilot reverses that to elevator nose-down, the elevator will have slightly greater authority until MCAS backs out the stabilizer deflection. But I think that would be the only significant effect.

          • “4 degrees positive lift to 14 degrees negative lift”
            Is this correct? Bjorn says the wing bends the slipstream. Even at 4 degrees leading edge up, if the aircraft is trimmed like that with no elevator, isn’t it supposed to still be producing negative lift?

          • Ted, there is a force summation for the elevator and stabilizer, with regard to total positive or negative lift at the tail. They may work together or opposed, depending on the circumstances.

            Considering the stabilizer alone, the transition from positive to negative stabilizer lift depends on the initial level trim position, and the airspeed which governs the amount of added deflection from MCAS.

            A normal situation might be with the initial stabilizer level-flight trim at 2.0 degrees of negative lift, thus providing a down-force at the tail. The elevator is neutral so no force contribution, the stabilizer down-force is balancing the inherently stable nose-down imbalance of the aircraft.

            Now if the pilot pulls back on the column, the elevator adds additional down-force, and the nose goes up. If the nose rises far enough to trigger MCAS, MCAS begins to move the stabilizer toward neutral, and if necessary, beyond neutral to positive lift angles.

            At the transition from negative to positive lift, the stabilizer begins to slightly contest the elevator down-force, but remember the elevator is already nose-up in order for MCAS to be triggered. The pilot still has the elevator authority to go further and stall, if he wants it.

            For MCAS stabilizer movement, we know that the high-speed limiting case is 0.6 degrees. So in our example at high speed, the stabilizer would move from 2.0 to 1.4 degrees negative lift. So in that case, the stabilizer still generates down-force on the tail.

            For the low speed limiting case, the MCAS movement is 2.5 degrees. So in our example for low speed, the stabilizer would move from 2.0 degrees negative to 0.5 degrees positive lift. So now the stabilizer generates an up-force on the tail.

            These forces must be summed with the elevator to get the total positive or negative lift at the tail. With the column back, the elevator is generating a down-force this whole time. As intended, the elevator can always dominate the MCAS deflection of the stabilizer. So in both cases, the elevator plus stabilizer still results in a net down-force, thus holding the nose up.

            If the elevator returns to neutral, then you have MCAS still providing either a below-normal down-force (high speed case), or an up-force (low-speed case), so the nose will come back down. As it falls below the trigger threshold, MCAS will back out it’s deflection and the stabilizer will return to 2.0 degrees negative lift, for level flight.

            Note I ignored the AoA of the tail to keep this simple, as it would also impact the transition from negative to positive lift. But this gives you the basic concept of MCAS.

          • Rob, you wrote a lot.
            You would have got less wrong with writing less.

            tail plane is an asymmetric profile.
            for zero lift you need some negative AoA.
            Then keep in mind that the profile is bottom up
            to create a downward force.

          • Uwe, I reviewed what I wrote and it is correct, as per my intention to help explain MCAS. The negative and positive lift angles quoted are relative to the zero position of the stabilizer, in terms of alignment with the fuselage, and assume a symmetrical profile.

            They are not true AoA of the tail, as I mentioned at the end. If the stabilizer has an asymmetrical profile, that too changes the relative angle of the transition from positive to negative, just as AoA would, but again does not change the principle of operation of MCAS.

            I was trying to convey the motion of the stabilizer due to MCAS, and how it interacts with motion of the elevator and the dynamics of the aircraft. I kept it simple to isolate the effect of MCAS from other factors. I don’t have the airfoil data to give exact angular values, but they aren’t needed for basic comprehension of the concept.

      • Rob,

        The stabiliser is being used to control pitch stability by producing a significant amount of upward force. So the stabiliser is being used to control AoA. That means MCAS is being used to control AoA.

        For the record. At 2.9°, 1.3 units, the yoke force was 82lb. It didn’t work. At 3.9°, 0.3 units, the yoke force was 93lb. The maximum as set out in regulations is 70lb. The Lion Air crash report doesn’t give a number for 2.6°, 1.9 units.

        The problem I’ve got is that the 737 was designed with wing lift aft of CoG with the tail producing a down force by default. So the 737 is not designed to have wing lift forward of the CoG with the tail producing an upward force by default.

        But let’s fix the stabiliser. Deflect the evelevators, trailing edge up. This increases the down force causing the AoA to increase. The stabiliser is now at a positive AoA to the airflow. Neutralise the elevators. The stabiliser produces an upward force. This brings down the AoA. The stabiliser transitionin to a downward force

        The above is what should happen when the wing lift is aft of the CoG with the tail producing a down force by default. But is it happening?

        Specifically after elevating the AoA using the elevators does neutralising the elevators bring down the AoA? If they do, then the airplane is naturally stable. If not, the airplane is not naturally stable.

        Further, the stabiliser is being moved upward by MCAS, leading edge up, as the AoA increases. When that happens what’s happening to the elevators? I think the stabiliser is contesting the elevators causing them to lose authority.

        The above are the questions EASA needs to answer.

        With regard to a linear moment curve. That’s the job of the elevators unless they don’t have the authority to do it. It’s not the job of the stabiliser. That’s why the JATR report uses the word “novel” to describe the use of the stabiliser.

        I’ll end by making clear airplanes with a canard typically have a tail that produces an upward force by default. The canards also producing an upward force by default. The nacelles can be thought of as canards because of the forward and upward mounting of the engines.

        • Philip, I can only emphasize again that MCAS as intended, does not control AoA, but only the force experienced by the pilot on the control column.

          It controls pitch stability by presenting the correct control feel and force to the pilot, as required by the regulations. It linearizes the pitch moment curve at the point where it becomes non-linear. It does not alter the AoA, which is under the control of the pilot via elevator, at all times.

          You asked:

          “Specifically after elevating the AoA using the elevators does neutralizing the elevators bring down the AoA? If they do, then the airplane is naturally stable. If not, the airplane is not naturally stable. ”

          The answer is yes, if the pilot lets go and the elevator goes to neutral, AoA will be reduced both with and without MCAS. With MCAS, the correction will occur faster as the stabilizer is applying an enhanced force, the difference being equal to that required for consistent control column behavior. That will be true, with diminishing effect, for up to 10 seconds after release, until MCAS fully backs out.

          You asked:

          “Further, the stabilizer is being moved upward by MCAS, leading edge up, as the AoA increases. When that happens what’s happening to the elevators? I think the stabilizer is contesting the elevators causing them to lose authority.”

          The answer is that the elevators retain authority, in fact the aircraft can only be held in the high AoA condition with elevator authority. It cannot get there otherwise. The stabilizer is contesting enough to add some force to maintain consistency, but not nearly enough to overwhelm the elevator or the pilot, and alter the control of the aircraft, or the AoA.

          I think the issue here is your premise that MCAS is taking control from the pilot and changing AoA, based on it’s own schedule. But that is not how it works, when implemented properly.

          Also from the Lion Air crash data, the column force was fluctuating between 50 and 75 lbs at 2.5 degree deflection. So I think Boeing has probably considered this in setting the maximum deflection.

          • Rob,

            If your answers to my questions are right, then there is no need to use the stabiliser in the fashion it’s being used. Let’s see what EASA says.

            You really need to do more research on moment curves. The moment curve we are interested in is the moment coefficient versus AoA. So if MCAS is trying to maintain it’s linearity then MCAS must be controlling the AoA for it’s one of the axis of the moment curve.

            But, anyway, controlling the moment curve is the job of the elevators not the stabiliser.

            Can I though agree with you that stabilisers can produce lift without making an airplane unstable. To my surprise even Wikipidea got it right. I look at Wikipidea because I want to know where some get their information from. Wikipedia is often wrong. So what does Wikipedia say:

            “The fundamental requirement for static stability is that the aft surface [tail] must have greater authority (leverage) in restoring the disturbance than the forward surface [wing] in exacerbating it.”

            Bang on right. The link:


            So an airplane with wing lift forward of the CoG is allowed provided the tail is big enough and fast enough to control it. The key is the neutral point. That must remain behind the CoG. The neutral point is calculated using all forces acting on an airplane, including the tail. So tail strakes will work because it moves the neutral point back. A bigger stabiliser and elevators will work because that would do the same.

            But Boeing’s solution is to use the stabiliser to generate a significant upward force. I do mean significant. The stabiliser upward deflections are large, so the upward force is large. This means the forward lift is large.

            I always use precedent. The only airplanes flying with this kind of aerodynamic configuration are military combat airplanes. In all cases they have computer controlled, large all moving stabilisers with high speed/high precision hydraulic sero actuators configured for triple redundancy.

            The pilot also get an ejector seat. So if the pilot loses it, the pilot can get out.

            The MAX has a single electric motor and a jack screw that moves the stabiliser at 0.26°/second, a snails speed.

            The MAX does not have ejector seats.

            The aerodynamic configuration of wing lift forward of the CoG with a tail producing upward force is the world of military combat airplanes. The configuration means the nose wants to go up, improving turn rate.

            Civilian airplanes should have an aerodynamic configuration where the wing lift is aft of the CoG with a tail producing a downward force. So the nose wants to go down. The nose wanting to go down is always safer than wanting to go up because of wing stall.

            Let me also address downwash. The downwash does reduce the effective AoA of the tail in both directions (climb and decent). Does it change the theory. No.

            Having said that, the wing/engine mounting will cause a downwash that is exceptionally turbulent. This may be affecting the authority of the tail, as suggested by another poster

            But bottom line:

            The stabiliser is being used to generate significant lift to control the forward lift of the nacelles. Why? The reason is there is something wrong with the elevators. Either they are too small to control the forward lift or they are losing authority for some other reason (downwash). Equally, using the stabiliser in this fashion, is contesting the elevators causing additional lose of authority.

            Ergo, the stabiliser is the primary control system for pitch. That means regulations that address primary control systems must be imposed. Triple redundant computers, triple redundant sensors, triple redundant power sources. High speed, sub-second responses. Nothing less is allowed.

            I’m not flying in it.

          • Philip, I think we just disagree on the true role of MCAS. As long as you see it as controlling AoA, by changing the AoA curve for a given moment, you will view it as dominating the elevator and leaving it with insufficient authority. I agree that is what happened in the accidents. But MCAS was never intended to work that way.

            If instead you see MCAS as adding a corrective force to the control column, by changing the moment curve for a given AoA, then it has no need to dominate the elevator, or diminish its authority. In fact it doesn’t dominate anything, since only a relatively small force is needed.

            The difference between these two views is obviously perspective, along with the aggressiveness of MCAS. To change the AoA, it has to be aggressive. In the accidents, the malfunction was extremely aggressive, utilizing the full deflection of the stabilizer.

            To alter the moment enough to adjust column force, it doesn’t need to be aggressive at all. The moment arm to the tail is much longer than the moment arm to the nacelles. So the applied force at the tail can be much less than at the nacelles. Thus in the new version, which follows the original intent, it’s far less aggressive and has far less authority.

            At the accident flight airspeeds, the MCAS motion of the stabilizer now would be less than a degree, probably less even than that needed for down-force in level flight. So difficult to see how that has any significant impact on elevator authority.

            Lastly, another point where we disagree, the size of the elevator or tail. A larger elevator will shift the moment curve, but not straighten it as MCAS does, and as required by the regulations.

            The other solution you mention, aerodynamic strakes, might fall somewhere in between. They would be passive rather than active as MCAS is. We can’t know without data, Boeing said they tried various things and they didn’t work. That’s all the information we have.

          • Hang on, the center of lift of the wing and engines moves forward of the center of gravity? I don’t think that has been proven. Wouldn’t that be against regulation on any commercial aircraft?

            If larger engines with a short moment arm increase rotation one way, wouldn’t a larger horizontal stabilizer with a long moment arm be a solution? By the physics that a larger surface produces a greater change in force by the same degree of rotation. Not that it is an economical solution at another 10 billion?, so I can see why using MCAS is preferred, just in theory.

          • Ted, you’re right that CoL should not move ahead of CoG in a stable aircraft, and that this wouldn’t be allowed for a commercial aircraft.

            As far as the larger tail/elevator/stabilizer, that changes the forces available in an overall, general sense (shifts the entire moment curve), but doesn’t do what MCAS does (straighten only the hook region at the end of the curve).

            The reason the hook exists, is that the nacelle lift is an increasing function of AoA. That lift, existing slightly forward of the wing, moves the aircraft CoL forward. So to counteract this effect, you need a change in force on the tail that also varies with AoA. Yet we want that change to also maintain the same control behavior and relationship on the column, that is present in the linear region of the curve.

            MCAS does this by introducing a calibrated change in tail force at high AoA, in the non-linear hook region of the curve, but not in the linear region, where it is not needed. A larger tail would add this force everywhere on the curve. It would give greater authority along the entire length of curve (shift it), but the issue is not (and never was) the amount of available authority. The issue is the targeted modification of authority in a specific region of the curve.

            The goal is adjusting the authority in the hook region of the curve only, so as to straighten that area of the curve, to get the desired column behavior, but leave the rest of the curve alone.

            If you boost or shift the entire curve, the hook is still there, and you’ll still feel it in the controls, they’ll still not meet regulation. You’ve just increased the mechanical advantage of the elevator across the entire curve, but have not targeted the hook region.

            Bjorn explains this well in his series on pitch stability. He shows diagrams of the curve with and without correction. The difference is that the hook is being straightened. It doesn’t become perfectly linear, but it becomes closer to linear, enough to satisfy the regulations. As you said, it’s a cruder form of control than a closed-loop system that would make the curve perfectly straight.

            Philip has suggested strakes or another aerodynamic solution. We know that Boeing favored that as well, it was recommended by the simulator test pilot, and they tried various things in the wind tunnel. The conclusion was that nothing gave the needed isolated behavior in the hook region of the curve. So they went to the active MCAS idea, since it had been used successfully before in the KC-46. It does give the isolated behavior, by using the stabilizer to counteract the nacelle lift, and modify the control performance in the hook region only.

            This concept of targeting the hook, is really key to understanding the intended purpose of MCAS. Unfortunately, I think the accident behavior of MCAS is permanently etched in people’s minds, such that the image of MCAS forcing the nose down, and opposing both elevator and pilot, is difficult to overcome. The idea that it would just add a small corrective force, is difficult to accept. It leads to the conclusion that it’s either not needed at all, or is easily accomplished in some other way.

          • Rob, I don’t disagree that there is a hook. The up force by the engines is not linear with change in AOA.

            I just think the basics are area and moment arm. The engines have a bigger area and moment arm. A bigger area and moment arm on the tail should increase stability. In an apples to apples equal weight scenario, a 900 should be more stable than the 600, a MAX 9 should be more stable than the MAX 7 at high AOA.

            For one change in degree, the elevator has to make up the down force lost to the stab. The bigger the stab, the more force it has to make up.

          • Ted, yes the basics are moment arm and area, and you can design a tail to arrive at the right balance, for any one value of AoA. But you can’t grow or shrink the tail in flight as the AoA changes. That is the needed effect. There isn’t an easy way to do that with passive designs. That’s why MCAS works better as an active system.

            If you overdesign the tail for the worst case, you end up with drag and weight penalties. And you’re designing for a flight condition that almost never happens. An MCAS-like solution is desirable because it addresses the rare case, without incurring penalties for the normal case.

          • First off, I know zero about aerodynamics, CoL, CoG. But, as AoA increases, the main wing loses lift. The engines still produce the same thrust, just vectored more in a lifting direction, and less in a thrust direction. Does that extra engine lifting, apply to the point of contact with the wing, adding to the CoL at that point? So, if an airplane is at a wing stalling point, the CoL will be mostly at the point of the engine attachment to the aircraft?

          • Richard, the main wing lift increases as AoA increases, until the critical angle is reached. At that point, airflow separates from the wing top surface which causes it to stall, with lift decreasing suddenly and sharply.

            The engine thrust is always in line with the aircraft direction, since the engines are fixed to the airframe. Thrust does not cause the CoL to move forward, although thrust does exert a nose-up torque on the airframe, due to being located below the wing. This is true for all underwing podded engines. Since the MAX has engines mounted high on the wing, this effect is lessened over more typical designs.

            Rather, the engine nacelles increasingly become aerodynamic surfaces, as AoA increases. They have no contribution to lift at small AoA, but an increasingly larger contribution as AoA increases. This moves the CoL forward, as now there are two mini-wings out in front of the main wing.

            In level flight, the CoL is somewhere near the aft wing root. The CoG is somewhere around the front wing root. The distance between them is what generates the nose-down torque that is needed for aircraft stability. Balancing this torque is the stabilizer on the tail, which exerts an equivalent nose-up torque. This is what a properly trimmed stabilizer does in level flight. The aircraft is in equilibrium with regard to forces and torques.

            At high A0A, the nacelle lift becomes a factor and moves the CoL slightly forward. This lessens the CoL-to-CoG distance, and thus the nose-down torque. So now the stabilizer balancing nose-up torque is too high for the conditions, and the aircraft wants to continue going nose-up (or nose-happy in Bjorn’s words).

            The pilot senses this as a softening of the control column forces. So MCAS moves the stabilizer to a more nose-down position, thus balancing the aircraft at the high AoA condition. So MCAS effectively re-trims for high AoA..

            If the pilot increases AoA to stall, that will be the forward-most position of CoL, but the problem is that lift falls away at that point. Therefore the CoL-to-CoG torque falls away as well. The main wing is designed to stall before the tail, so the tail becomes the only active aerodynamic & control surface at stall.

            The tail is not nearly large enough to oppose the aircraft weight acting through the CoG. So the aircraft will quickly go nose-down, which lowers the AoA and allows the aircraft to accelerate and regain lift in the main wings. All commercial aircraft are designed with this natural recovery behavior, as a matter of basic stability.

            I think if you understand that MCAS is re-trimming for high AoA, and by doing so also helps to maintain column forces, it won’t seem so hazardous. In the accidents, it ran away due to a bad sensor together with insufficient redundancy and safeguards. Those things have been addressed now.

      • Philip,

        I have followed your theories closely, including yours and other’s ideas about the responsiveness and quality of of the stablizer jack screw, and the problems of the trim wheels, and the meltdown of the FCC. Here’s the problem, and please read carefully what I’m saying. I don’t have enough knowledge to know if you are right or wrong. But the implications of what you say and the proper fix for it suggest a problem of nearly unthinkable proportions. The financial calamity is mind boggling. It would be a nearly irreparable SNAFU. So, the question remains. Is it at all possible for software and minor physical tweaks to bring the dimensions of the problem under control with a justifiable and rational fix? Could a safe plane be sent back in the air after undergoing these fixes no matter how traditionally undesirable? Would airline companies and I have confidence in this aircraft? With my soft knowledge, I’m very skeptical about the latter, especially in light of the steady trickle of information that keeps leaking out. And there is very little, with the exception of positive posts on this site and some spin in the daily news that has worked to restore hard confidence. I’m not sure how this can change. At the very least, every regulatory agency in the world has to agree that the Max is a safe airplane without a single exception.

        • Steve,

          I will begin with the word unstable. I’ve refused to use it. Instability? Yes. Unstable? No. Unstable as a specific meaning in aeronautical engineering. It means the neutral point is in front of the CoG. That’s not the case with the MAX. But it does have significant instability.

          So I come to the correct words. Extremely forgiving. A significant margin for error. Civilian airplanes must be extremely forgiving, they must have significant margin for error. Why? Pilots make mistakes. They must be given the time to correct the mistake.

          So we come to Boeing’s history. They have a history of building airplanes that are extremely forgiving, that do have a significant margin for error. The 707, 717, 727, 757, 767, 777 and the 787. The same applies to early incarnations of the 737. The MAX is different. It’s the runt in the litter. And what a runt.

          But the point I’m making is that Boeing do know how to build airplanes that are extremely forgiving, that do have a large margin for error. History shows that.

          This comes to regulation. Regulations are beyond established.

          Primary control systems need triple computers, sensors and power sources. They must provide sub-second response times. There is leeway, provided the airplane is rock solid aerodynamically. The MAX is not rock solid aerodynamically. The MAX does have significant instability.

          The use of MCAS as clearly set out in the Lion Air crash report makes clear that there is significant forward lift that requires the stabiliser to be used to produce a significant upward force to control it. The history of such airplanes is appallingly bad. They crash a lot.

          Are there fixes? Yes? I set out the two fixes a long time back:

          1. An aerodynamic fix using a much larger tail. There are many ways to make the tail bigger. Take your pick, they all work.

          2. An all moving stabiliser using whizz bang high speed/high precision hydraulic servo actuators in a triple redundant configuration.

          They are the two fixes. So returning to regulations. There is significant precedent with regard to the first fix, an aerodynamic fix. The regulators have given their approval many times. The second fix. No, not for civilian airplanes. Never been used. It’s world is the world of military combat airplanes.

          So to answer your question. Yes there is a fix and an established one. A bigger tail. How long would it have taken? About a year.

          Remember LNA asked a guest writer to write an article. The guest writer used the 707. The orginal 707 had insufficient yaw stability. An aerodynamic fix was implemented. The rudder was made bigger. It took about a year.

          The Lion Air crash report makes it clear as to what MCAS is being used for. There can no longer be any doubt. It’s not safe without doing the upgrades as required by the second fix. But if the upgrades were done, it would set a precedent for civilian airplanes.

          I hope I’ve answered your question?

          • The MAX is stable and forgiving, it just has a need for control force correction at high AoA, in a regime that is rarely encountered in flight.

            As Bjorn pointed out, even without correction it’s perfectly stable, it just doesn’t meet the control force regulations for that one condition.

            With regard to inherently unstable combat aircraft, parachutes, high-speed servos, frequent crashes, being inherently unsafe, I honestly don’t see any comparison to the MAX at all for those things..

          • @Rob

            “The MAX is stable and forgiving” except those situations where is not, except some parts of envelope, except some manoeuvres…

            Unfortunately Bjorn is affected by Boeingitis, which proved few times.

            MAX has instability, question is how big, if pilots can handle it without MCAS and without entering into danger zone. EASA will check it in live tests.

            I agree with your teory and summary. Well argumented.

          • “The MAX is stable and forgiving, it just has a need for control force correction at high AoA, in a regime that is rarely encountered in flight. ”

            Reduction of control forces means you are entering a “more stable” attitude.
            Final out come is that the MAX has a tendency to being stable in stall a stall attitude.
            This is unacceptable for certification.
            .. and it is irrelevant if this situation is “rare” or not.

          • Point being the MAX is well-behaved, as are all members of the 737 family, and is not some wild uncontrollable & unstable beast with impossible controls and a desire to stall.

            Bjorn understands this, other pilots understand this. I have not seen anyone who has actually flown the aircraft make those claims, which defy all reason and common sense.

            Every pilot I have seen interviewed or spoken with personally, has said the MAX is a good aircraft, with the MCAS problems corrected.

            The ultimate verification will be RTS, so we just have to wait for now.

    • ” I’ve seen very little, if any coverage of this question about the current jackscrew on 737-MAX’s.”

      Suggest you are confusing the Douglas design for a jackscrew with the boeing design- type . They both have course threads but nothing else applies. Boeing has used a ball screw ‘ nut’ instead of a simple high friction nut, etc

      And that is just part of the real differences.

      Please take the time to look up the facts and data the differences

      • Bubba,

        It’s a case of the Scott who would not open their wallet to buy a round of drinks.

        Manual trim needs a power source. Even better a back up to the power source.

        Did Boeing open their wallet? No.

        Concequence, runaway trim stabiliser is catastophic.

        All for a few quid. I’m a Brit.

        I would apologise to the Scott but it’s true.

  24. If MAX wasn’t grounded BA would be racing to deliver as many as possible to EU operators prior to potential import duties being imposed. As things stand now, maybe 25% of the MAX backlog could cost a lot more to deliver than anybody planned on. As noted by one poster above, a chain of hits in progress.

    Agree with TW that BA will survive, but share values can only go down & capital costs up. Need NSA launch now no matter how questionable the technical business case.

    • I think NSA or NMA launch would do wonders, both would be great.

      Internal Boeing needs reform though for long term success.

      The stock may go down but it has enormous plus assets.

      Its no where near Penn Central.

      Fail on MAX, 777, TR-X etc and it could be, but that is 10 years down the road.

      • “The stock may go down but it has enormous plus assets. ”

        In another thread I’ve brought up the concept of “Cargo Cult” and “Wagging the Dog” and its application to the share holder ecology workings.

  25. There are a lot of what ifs here, what if ba cant get stable flight with updated software and the tail requires rework. what if spirit and the other suppliers lay off their workforces and then cant get them back easily, what if ab negotiates a guaranteed 75% of all leap production, what if ab does offer the a220 in 500 and 700 versions this year,

    Ba wont offer a regional 787 due to the fact that parts are ordered 2+ years in advance of production and airlines need their ac now.

    Workforces will migrate to other areas industries if long layoff periods are forseen, this i belueve would be the biggest issue to ba as without a fully trained workforce, and to the numbers required, then production to the quantity and volume required will be impossible for years to come.

    I think ab will offer the a220 in 500 and 700 versions very soon, going for the throat is exactly what ba would do to ab given the chance.

    It wasnt all computerised issues that are failling in the max, trim runaway is also a major issue, if stable flight cannot be provided with a patch then structural rework maybe needed, this could set ba back another 6/12 months, especially for all the completed ac that would have to be reworked. The faa has to be spot on this time, any more fatal crashes due to missed problems with re certification will kill the max completely and to a lesser extent the faa.

    This is troubled times for ba, a fsa should be top of the agenda for the company moving forward from this whole debacle.

    • Just a point of fact, a 787 Regional require no new parts, simply fly at lower fuel levels per the A330 Regional.

      While the A220-500 is probably a done deal, stretching a 5 seat fuselage past that? I don’t see it.

      Clearly Boeing has challenges and issues. 4 months from now all predications will have been wrong in a major way.

      This is a moving target, not a static one.

      • “While the A220-500 is probably a done deal, stretching a 5 seat fuselage past that? I don’t see it.”
        A220-100 35m length
        A220-300 38.7m
        A220-500 ?? but probably less than 5m extra as 4 extra rows is 20 seats

        You have forgotten about the 5 a-breast MD90 which came in at 46.5m length. Technically not a problem and they had to have more fuselage in front of wing.
        Delta flies them with 158 seats and thats US style 3 class

  26. As pointed out above in the comments, it appears Boeing was so concerned with killing off Airbus and Bombardier models, that it lost focus on building planes. That was the intent of their leadership; their board and ultimately their owners – also referred to as the major, major shareholders, not scrubs like me who own a few shares. Hopefully, this tragedy will be studied in anti-business schools for years to come. It will be under the chapter title of Hubris, men totally committed to shareholder value that morality was replaced with greed. I hope that chapter includes pictures of men (and women) in striped pajamas.

    • I think that will depend ultimately on how many of the dozens of problems suggested for the MAX to possibly have, end up in the final airworthiness directive as things that must be changed before RTS.

      The ones that have come out publicly are MCAS, FCC reconfiguration, and pilot training. We know these will be included. The first and last are obvious consequences of the accidents. The second is a safety improvement, it was not a contributing factor.

      Things we know are under consideration for inclusion, either now or later, are third AoA sensor, wiring bundle separator, engine rotor inspection, rudder cable protection, lightning panels, and slat tracks. The last two are already done or will be as part of RTS preparation. The others are undergoing further study.

      There is no on-going work on trim wheels that we know of, or jackscrew, or stabilizer brakes, or elevator controls. As others have pointed out, those things would be retroactive to all aircraft that use them (as the wiring bundle separator also would be).

      So if it comes down to only the known changes, it might also be that the business school study will be on the extreme cost to identify things that were more or less known in the beginning, once under the microscope. Or why you shouldn’t run afoul of the regulators, and the potential cost if you do. As Bjorn pointed out, far less costly to comply in the beginning than to make corrections in the end.

        • @Ted: It was discovered a manufacturing/assembly error stripped some of the lightning protection on a spot of the CFM MAX engines. It shouldn’t be too hard to fix.

          • Yes, 737 issue was panels not installed properly to have electrical conductivity, on some aircraft, so not intentional.

            787 was intentional in that Boeing requested approval to stop including the panels in future production, then went ahead before the FAA ruled. The FAA denied so then Boeing appealed, and may have used the reasoning (judging by internal complaints) that it was already in production. FAA then approved but based on the complaints, it’s now under review again. In the meantime, Boeing continues to omit the panels in production.

        • Rob:

          Boeing was so focused on shareholders it lost sight of the balance.

    • That is not quite what happened in reality.
      Boeing discovered that extra toolbox that allowed to compete away from technical merit.
      Gaming the FAA and gaming the share holder ecology.

      This was an elastic advantage. i.e. it was a karma energy storage “thing” that released its might on a major error.
      Here it was the materialized incompetence associate with the MAX.

      Boeing has a range of “karma energy storage” places that will go boom on a sufficient trigger ( start with 787 deferred cost basket, continue with “grandfathering to haunt you” on the 777X, … and now large amount being pushed into the MAX deferred cost basket ).

  27. No one here refer toChinese way of conducting business
    I mean a very strong communist style of management playing with some capitalist laws
    A huge market (local= ROW)
    able to build 26000 Km of fast track for fast train in +/- 15 years even if at this time some itineraries are big losses maker.
    able to build millions of mobile phones in entirely automated factories
    able to move factories from Cambogia to Africa saving on salaries (sewing clothes)
    Strong education system
    and so on
    Next step for Boeing is to recognize they are already out of business and sell all his businesses to well managed companies.Renton and its suppliers becoming another FAL for Airbus or Comac or Irkutsk
    if some money is left give it to shareholders if they do not want to have shares in the bying companies!!

    • That is truly an interesting and out of touch with reality outlook.

      Interesting to see the difference between Airbus stock value and Boeing.

      And that is despite the MAX and the shareholder buy back termination.

      Its going to take a whole hell of a lot more to kill Boeing off than has occurred.

      I see countries in total distress that are still staggering along and Boeing is far from total distress.

      Very troubled, for sure. Penn Central, no.

      • “”Its going to take a whole hell of a lot more to kill Boeing off than has occurred””

        Wait for the fines, they could reach triple digit billion $.

  28. Whatever FSA is built now has to be fully ‘idiot proofed’ as any third world crashes would jeopardize the whole $10-20 billion program. That is quite a task in itself.

    Alternatively, Boeing could focus initial sales for the first 36 months on exclusively western airlines.

    It will be interesting.

    • I read an article on Boeing stepping up research into autonomous systems, after these accidents. The cost of pilot error is huge when an aircraft system failure is also involved. The lesson learned is that the pilot & airline error will be overlooked but the system failure will not.

      It’s interesting also that safety is strongly associated with the manufacturer/aircraft rather then the operator, whether pilot or airline. That means the public believes that safety is engineered into the product rather than the result of good practice.

      The Flight Safety Detectives had a good podcast on third-world safety management. They used Korean Air as example, they had 7 incidents in 5 years, and many before that. But then they were receptive to input from the NTSB and other safety agencies, and completely turned that around, now are considered very safe.

      So it can be done, but there has to be acknowledgement of the problem and willingness to change. We didn’t see that from Lion Air, but Ethiopian may be better.

      • Or maybe don’t put a very bad implementation of FBW to solve a pitch moment curve issue onto a fly by cable aircraft. Don’t avoid pilot training at all costs, and don’t change the trim cut-out switch configuration !

        If the pitch moment curve issue is really as minor as we have been led to believe, do not implement a system that if it fails is more dangerous than the issue it is intended to solve.

        As additional simulator training has now been accepted, the best option (if the pitch moment curve really is as it has been portrayed) is to remove MCAS, and mandate specific training !

        BTW after a month of inactivity, N7201S has been flying again.

        • Jakdak, to do as you say would require an exemption to the regulations. The regulators have that power if they wish to exercise it. I doubt they will, they want the MAX to be compliant.

          Boeing is responsible for botching MCAS, they have taken responsibility for it and have tried to correct it. But MCAS alone did not ensure a crash, as we know from JT043. To say that the errors made by pilots were insignificant, or can’t be corrected, is not being truthful.

          When Boeing ran the pilot testing simulations last month, they found that pilots made mistakes that delayed resolution of the problems they were given. That is what changed the course of the training argument. It’s futile to resist training when it’s clearly needed.

          Resisting it was one of the mistakes that Boeing made, but they are by no means alone, airlines have been complicit as well. Training is expensive.

          The better view is that training is a necessary cost of promoting safety, just like certification, rather than an expense to be avoided. Normally training is an operator cost, but Boeing will now contractually pay for some of it as well.

      • Would you ride on an autonomous plane designed and manufactured by Boeing who have had various run-ins with design, manufacturing and certification “problems” in recent history? Failing in basic engineering: researching and understanding the task set! ( looked at the loss rate of US drones, the nearest thing to autonomous flight, perchance ? )
        I would not.

    • Alternatively, Boeing tells the FAA and airlines about hidden systems and trains pilots accordingly? There’s a chance that might work as well.

      • Both valid points, and mistakes that Boeing made.

        However you’ll note that in the Ethiopian accident, MCAS was not hidden and a pilot bulletin was issued with training info. It made no difference, because basic mistakes were still made.

        That doesn’t excuse Boeing at all, but it does reinforce the notion that there were multiple contributing factors involved. Good safety management would go after all those factors.

        • Oh yes @Rob, it was hidden.

          Then MCAS even wasn’t named, nor by Boeing nor by FAA after JT610. The pilots received flawed recovery procedure (runaway stabilizer), weren’t been told that it’s enough to extend flaps to cut MCAS, weren’t been told about yo-yo, also weren’t been told about extreme forces on out of trim stabilizer. Look to AD 2018-23-51 issued by FAA at 7/11/2018.

          Easiest thing to blame dead pilots.

          • Pilots were given a procedure to deal with the issue. The procedure was not followed correctly. Also the pilots exceeded Vmo of the aircraft.

            These are facts, they are not blame. To ignore them is not to be truthful, and increases the likelihood that similar errors can happen again.

            That is the culture being reinforced by those who attack the identification of pilot error. It may be well-intended to protect the reputation of the pilots, but I’m sure those pilots would want others to learn from their mistakes, and not suffer the same fate. Any sane person would want that.

        • Rob,

          This is fundamentally why I am suspicious of your other posts. This is old, unwarranted, marketing spin on the “Ethiopian accident.” Your response is somewhat indefensible. It does not rely on a careful balancing of known facts. Above all, there has been no accident report! Below is the most competent thing I’ve read about pilot judgment and the accident. It is written by a pilot. And one must first begin with the bragging of the Max test pilot who falsely sold company after company on the idea that the Max flew nearly exactly like previous generations of the 737 with little extra training necessary. I can’t say anymore. My mind isn’t made up, but I am compelled to read your comments through the lens of this article until it has been factually disputed.

          • RealSteve, thanks for providing that article. It gives a good and accurate pilot perspective of the experience of being on that flight. I don’t doubt it was a harrowing experience, and that the pilots did the best they could.

            In what follows, I also want to not confuse identifying fact with identifying blame. I’m not trying to assign blame to the crew, or deflect blame from Boeing. Saying the crew made mistakes is not the same as saying Boeing didn’t make mistakes. Mistakes are not unique or mutually exclusive to anyone.

            We know that MCAS was seriously flawed. Boeing has admitted this and has tried to fix it. This has already received enormous attention. So I will not discuss MCAS here, while acknowledging it played a major role. But it was not the only link in the accident chain, or the sole cause of the accidents.

            So in that spirit, I’ll point out some things that occurred that could have been done differently, to reach a different outcome. Hopefully these are being incorporated into future training.

            1. Stick-shaker left side only

            Procedure in this case would be to cross-check the two instrument sides, and also compare to the third independent indicators. This would identify right side as valid, without any risk of stall, and left side as invalid.

            Instead the pilot seemed to either follow the left side, or distrust the readings altogether.

            2. First MCAS activation

            MCAS engages and moves the stabilizer from 4.6 to 2.1 units. As noted, this is a huge change that should never happen. It is also the final condition to confirm the emergency AD bulletin conditions. At this point those conditions are all fulfilled (other alarms were already present).

            Procedure at this point would be to do the runaway trim checklist, either as directed by the bulletin, or by the magnitude of the inexplicable change. Or alternatively, back out the change with electric trim, as the captain of Lion Air had done.

            Instead the pilot trims back only from 2.1 to 2.4 units. Yet he (possibly) knows that 2.4 is still an extreme value, that places the aircraft severely out of trim. And earlier he had instinctively trimmed nose-up to balance column forces, but he doesn’t do that now.

            3. Second MCAS activation

            MCAS engages again and moves the stabilizer from 2.4 to 0.4 units, near full deflection. The aircraft is now massively out of trim, and the control forces are very large. This is clearly runaway trim.

            Procedure would be as first priority, to trim the aircraft. Pilots do this, trimming back to 2.4 units, but that value is still severely out of trim, it only re-establishes the prior condition. They continue to struggle with the column forces without neutralizing them as per training and procedure.

            4. Runaway trim checklist

            The copilot, now correctly doing the runaway trim checklist, calls out “stab cutout” for pilot confirmation.

            Procedure would be to trim the aircraft to neutral before cutout, as cutout will disable electric trim.

            Instead the pilot confirms “stab cutout”, which defeats MCAS but leaves the aircraft severely out of trim. In view of other missed opportunities to trim fully back, the pilot may not realize this, possibly due to distraction, possibly due to misidentification of trim settings.

            5. Vmo exceeded

            The right overspeed clacker begins sounding continuously. Throttle should have been reduced earlier but possibly due to distraction, was not. Apart from the MCAS activation events, aircraft has been steadily climbing, and also accelerating.

            Procedure is to reduce throttle to reduce airspeed, aircraft is above 4000 feet and at 350 knots, not at risk of stall or high & hot issues.

            Instead the clacker is ignored, possibly because the pilot is still following the left side instruments, which show airspeed above 300 knots but below Vmo. They now have stick-shaker on the left and overspeed on the right, so possibly are confused.

            6. Manual trim wheel attempt

            The aircraft is now above Vmo but still accelerating and climbing, with control forces increasing at the square of the speed. Pilot realizes the aircraft must be trimmed, and asks co-pilot to try manual trim.

            Procedure is to crank the trim wheels, but the force required is too great. Speed must be reduced to use them.

            Instead co-pilot reports trim wheels won’t work. Overspeed clacker is still ignored. There’s not realization that excessive airspeed is affecting all the control forces.

            7. Reactivation of stab cutout

            Pilot concludes that electric trim is needed to trim the aircraft.

            Procedure is to not reactivate trim after a runaway event, but the situation is desperate.

            Pilot activates stab cutout switch, restoring both electric trim and the runaway source, MCAS. Yet pilot uses electric trim to move only from 2.1 to 2.3 units. This is his third time trimming back to the same out-of-trim value (2.4), so possibly pilot is confused about the needed trim setting. Or acting out of extreme caution, as the article suggests.

            8. Third MCAS activation

            MCAS engages again and moves stabilizer from 2.3 to 1.0 units. At over 400 knots indicated (nearly 600 mph ground speed), this is a violent and disastrous event. There are no more attempts at electric trim in the remaining 30 seconds of flight, nor would there be time to recover with electric trim. The pilots held the column back until the end. They had managed to fight the aircraft and MCAS, to continue climbing up until this final event.

            So obviously this is a sobering discussion, and we should be respectful of these people who lost their lives doing what they thought was best.

            One thing that struck me while writing this, is that the pilot’s actions are explained if he somehow thought 2.4 units was a good trim value, and not severely out of trim as it actually was. He stopped there 3 times while trimming back, even with all the problems. That suggests he may have thought it was a safe value. It’s also what he would have seen when looking at the trim indicator after the first MCAS activation. So maybe in the confusion he identified 2.4 as being neutral. The article suggests it was from caution and experience.

            Another explanatory thought, would be if he was still thinking in terms of the NG stab switches. He asked the copilot if electric trim was working after he had ordered cutout. On the NG, that would have been true, and may account for his surprise that his trim switches were not working. Also accounts for not trimming to neutral before ordering cutout, he may have thought he’d still have that option after cutout. The article suggests it was distraction or confusion.

            We can never know these things, of course, so it’s only speculation. But it helps to try to understand their decision process

            I hope this has highlighted the opportunities and decision forks that existed for a different outcome, without any attempt to either blame the pilots or absolve MCAS/Boeing.

            I realize as well that being in that cockpit and holding back the column with your full strength, would have impeded thinking and reasoning skills. In that environment your thought process collapses down onto the single task in front of you. So I would think of this more in terms of training issues, as training is what gets you through those moments.

            We can’t learn from mistakes unless we consider them. So I’d hope this could be a topic for discussion without rancor.

          • Rob,
            At play here is not only what the aerodynamic forces technically described by engineers, but what other disciplines technically call a hermeneutic; in this case both an engineering and critical hermeneutic of “forgiving.” On the engineering side, it relates to your and Philip’s question of whether the Max is a “forgiving” airplane. Boeing, says Philip in his post has a “history of building airplanes that are extremely forgiving, that do have a significant margin for error. The 707, 717, 727, 757, 767, 777 and the 787. The same applies to early incarnations of the 737. The MAX is different. It’s the runt in the litter. And what a runt.” You counter: “The MAX is stable and forgiving, it just has a need for control force correction at high AoA, in a regime that is rarely encountered in flight.” As a passenger, who often takes and whose children take long, transatlantic flights, I rely on regulators and over-strict regulations that relentlessly insist on “forgiving airplanes” and mechanical architecture that embraces a redundancy that assures my safety in the inherently dangerous undertaking of flight. I cannot be charitable or forgiving in my assumptions about an airplane when I get on one.

            But there are other issues of hermeneutical forgiving here that go beyond how much “forgiving” is built into the Max. There is forgiving or unforgiving of Boeing. Forgiving or unforgiving of the pilots. As a hermeneutic, this ethic guides all readings of materials related to the two crashes, and to the reading of posts on this site. This controls how one interprets facts, and in my case, it is fundamentally related to what can loosely be called, a “hermeneutic of suspicion.” The real question is if such a hermeneutic is misguided or justified. Reading through such a hermeneutic does not reveal a mind that is “made up,” but one that asks questions in a certain way concerning other, perceived ethics of “forgiving.”

            So, you’ve presented your reading of the facts, which is governed by a hermeneutic of forgiving that is inexorably charitable to both Boeing and the Max. My layman’s interpretations of the Ethipian crash and the death of all of those people is largely governed other facts and assertions from the article cited and another by blogger, Patrick Smith – and the bragging of the Boeing test pilot, who assured airlines that pilots familiar with the 737 needed little additional training to fly the plane safely.

            Many people have been critical of Capt.Yared Getachew, asserting that he didn’t follow the rules of basic piloting, repeating the mantra of “first, fly the plane.” Which plane: the 737NG or the Max? Wasn’t he doing that? I am haunted by these descriptions from Dave Walker. How should one interpret some of the following statements?

            “Many airline captains can go through their entire careers and never once take off at a density altitude of more than 9,000 feet. Captain Getachew did it routinely […].

            “Every airline captain in the world would be alarmed at having the stick shaker activate four seconds after takeoff. As an experienced airline pilot, my blood ran cold when I read this in the report. I’ve never had a stick shaker sound continuously outside a simulator. This event would have received Captain Getachew’s full attention. Remember: He is acutely aware of the aircraft’s heavy weight […].

            “Airline pilots learn to increase thrust when they are in doubt. Under no circumstances could I imagine myself reaching for the throttles and reducing thrust while the stick shaker was doing its thing, particularly not right after takeoff while operating close to the ground.”


            And then, I add to this somewhat unforgiving ethic of suspicion quotes from Patrick Smith about the 737, a plane in which Getachew had thousands of hours of experience (


            Smith says:

            “I was jammed into the cockpit jumpseat — more of a jump-bench, actually — on an American Airlines 737-800 not long ago, flying from Los Angeles to Boston. Man, if we didn’t need every foot of LAX’s runway 25R, at last getting off the ground at a nearly supersonic 165 knots. What would it be like on the westbound leg, I wondered — a longer flight, from a shorter runway, in the face of winter headwinds? […]

            “In the 737, Boeing took what essentially was a regional jet — the original 737-100 first flew in 1967, and was intended to carry a hundred or so passengers on flights of around 400 miles — and has pushed, pushed, and pushed the plane into roles it was never intended for. Bigger and bigger engines, fancier avionics, MCAS. Five decades and ten variants later, the MAX is a monsterized hybrid of a thing — a plane that wants, and needs to be something that it’s not: all muscle and power and advanced technology, jammed into the framework of a fifty year-old design.”



            Colored by these images, my reading of events shall remain forgiving toward the dead Ethiopian pilots and less so towards Boeing and the Max. At least until the accident report comes out.

          • RealSteve, I think coloring is the right word.

            I try to give the facts as best as I can determine them, as well as my interpretation of them and the reasoning by which I reach my conclusions.

            You try to give me your impressions as determined by your evaluation of what you’ve read and absorbed into your own views, including commentary from others here.

            So in that sense, our viewpoints are colored differently. I am open to the opinions of others, but also try to do my own evaluation. Is that really true? Since I work as a consultant, I can’t afford to be caught out by someone else’s view that was not properly vetted. My customers will view that as my mistake, whether or not it actually was.

            You are also open to the opinions of others, but your vetting process is more based on evaluating and establishing consensus among the many views you research. I give you major credit for being well-read and well-informed, that’s more than most people are willing to do.

            For an issue like the MAX, the truth is that a story about it being unsafe is news, while stories about it being safe are a snooze. The Internet is driven by clicks and taps. There are far more on unsafe than on safe. This means that there is a negative, critical slant for most stories that appear, because that generates the most traffic and the most profit.

            In some cases the negativity is fully justified by the facts, in some it’s not. Thus when I read things in the press, to me they are really only a starting point for understanding.

            This means if you build your viewpoints around consensus in the reporting, or the commentary, they are more likely to be negative than positive. As you said yourself, there is little in the way of positive reporting on the MAX, or even about Boeing at this point.

            In the elder days before the Internet, reporters had editors and were held to a factual standard, with opinions edited out. Opinion was reserved for the editorial page, and even then, the author had to have some standing in the topic. These were major controls on the distribution of information. Sometimes abused, but also necessary to assure truth in reporting.

            Today, many Internet stories are self-edited, or not edited at all, and opinions are freely mixed in with the reporting, with little in the way of credentials required. News anchors make judgmental and hyperbolic statements that would be unthinkable in the age of Cronkite, Brinkley and Murrow. Those guys prided themselves on being accurate and factual, and keeping opinion out. If they had an opinion, they worked to establish the facts to support it, and let those facts speak for themselves.

            The Internet is free and open and there is no regulation of information. That is both a good and a bad thing. Abuse through censorship cannot occur, as it did in the days of centralized news. But abuse in the form of misinformation, and substitution of opinion for fact, is rampant, in a way that it never could be before.

            So to end my diatribe, which Leeham may edit as off-topic, bottom line is, our views have different bases, and so may never really agree. You have caused me many times to go back and reconsider my facts, so I value that and thank you for it. I will continue to present the facts I find with my reasoning, I’m sure you will continue to express your views with your reasoning as well.

  29. David Calhoun (“The 7 million dollar man”) really seems to have stepped into it right out of the gate. Was he sleeping during the congressional testimony when Muilenburg’s bonus came up?

  30. Perhaps another order lost due to lack of NMA/FSA:

    The biggest all Boeing operator in the world that is not a LCC, Xiamen Airlines, has just decided to lease A321neo. It has always been all Boeing carrier and currently has 167 aircraft. Was the last airline in China to retire 757.

    • Rob: “Procedure would be to trim the aircraft to neutral before cutout, as cutout will disable electric trim.”. That is the whole point. The emergency AD is not at all clear about this. It does not state you MUST trim neutral before cutout. Believe Peter Lemme noted this too in his blog. Yes, my feeling is the tragedy of the Ethiopian flight that if the 2nd pilot had shouted ‘cutout switches’ say 10 seconds later as he did, things may have been different.

      I sometimes play patience or chess against my mobile. Of course sometimes you loose. By doing ‘replay game’ and guessing what went wrong making a better move, I then manage often to win the game after all. It is probably always possible to discover with hindsight how you can win, or in the case of our pilots, how they could have saved the aircraft. But that is not the issue. If you have a flawed MCAS, a flawed AD not instructing with enough clarity, and a manual trim wheel that does not work while the AD counts on it, you create a situation where when you play that particular game for a new situation that you are not at all familiar with, you most probably loose. Finding out with hindsight that there is a way to win does not change that.

      • atFlyer, I agree the AD was very terse and could have included more detail. They adopted it from runaway trim which was meant to be as general as possible. Since MCAS was a specific issue, they could have adapted it to include MCAS differences.

        If electric trim is working, it can be used to trim the aircraft before disable. Always keeping good trim is in accordance with best practice and is a fundamental part of pilot training. So it’s a lesson that can emerge from these events.

        As far as second guessing, that wasn’t really the intent. We can recognize what might have been done to improve, and learn from that, without saying that should have been done in the event.

        In essence I’m playing your game. The intent is to not to criticize yourself for not initially winning, it’s to learn how to win for the future.

  31. Maybe to make the point even clearer – it is not only a situation you are not familiar with, but a situation where the text book you have been given with does not give the winning guidance or is at least confusing about what to do. So by following and interpreting the text book, there is a fair chance you lose. At the same time, Boeing had created a situation where chess ace Gary Kasparov is your adversary. You then can argue that for you as a player that there is still a way to win, if you use superbly your brains, skills and experience, but it is all too clear finding the winning way out is extremely slim.

    • Again I agree. I believe it helps to understand the losing strategy, that’s why I tried to reason out a framework of logic for their decisions. We can’t know if those were their actual thoughts, but we can still learn from the scenarios.

      For example if the captain was trained on the NG, and in the emergency reverted to that knowledge as being most native to him, then very likely he is not the only pilot that is vulnerable to that issue. So maybe we should look at restoring the NG stab switch functionality, which makes more sense and is safer anyway.

  32. Why not have airlines keep One degree of flap in place, after takeoff, by procedure, until 10,000 ft AGL? It would restrict speed a bit, but, should be safer to have MCAS shut down and the pitch up issue not in play. In the Two previous 737-MAX accidents, it would at least have given them more altitude and time to save the plane. Altitude to use the yo-yo maneuver, if needed. Time to properly diagnose the multiple alarms and flight surfaces moving.
    And with the flaps active, Pilots would still have the manual electric trim available, without the interference of MCAS. With the new MCAS operating on Two AoA sensors, you have twice the chance of AoA failure, with no OFF switch for MCAS. This procedure would at least give you a software OFF switch to MCAS. I assume the flap sensor on the wing, is routed into the MCAS logic, which still offers a software failure mode, not a true hard OFF switch, but, it’s at least another attempt to control the black boxes from the cockpit, rather than the the black boxes directly controlling the plane.

    • The JT610 captain tried one deg flaps for some time, but it didn’t help, maybe because the FCC was slow.

  33. Here are some perhaps simplistic questions:

    Wouldn’t flying flaps down a lot produce a lot of drag, undermines fuel efficiency and destroy whatever competitive advantage the Max might hold over the 320 neo?

    Wouldn’t adding a larger tail do the same thing?

    Is it possible that the war of the future was fought long ago with the introduction of the 757, which by all accounts is an excellent airplane but not as successful as it should have been?

    Meanwhile airlines kept thirsting for and using the 737, even in the case of Southwest, building their business models around it. Adopting the 757 would have meant a new business model and training that would have competitively brought Airbus into the picture. So, Boeing kept producing and modifying it’s old workhorse.

    Imagine if the 757 became more popular and Boeing phased out the 737. It could have then hit the market with updated versions of it, which might have been great. Forcing airlines to make the transition away from one obsolete aircraft and towards retraining on another one would have been costly at the time, but solid long-range planning, it seems to me.

    Another problem is the old suspicion of fly-by-wire (if it ain’t Boeing, I ain’t going), a system which, when it comes to updating and training, is an indisputable asset.

    • RealSteve, just a brief answer this time:

      Yes to your first two questions. One advantage of MCAS is that it addresses the small part of the envelope where it’s needed, but has no penalty for the rest of the envelope where it isn’t.

      On the 737 vs 757 issue, you hit the mark when you said airlines determine the market by buying 737’s, or whatever else they choose to buy. Manufacturers have to be responsive. Attempts by manufacturers to influence the market often don’t work out. 757 for Boeing, A380 for Airbus. Both great aircraft, but the market went in another direction.

      Lastly on the FBW, that is unquestionably the future, but it will be implemented in ways that feel more natural to the pilot. Bjorn did an article on the A220 hybrid Boeing/Airbus approach to FBW. The 777 may be a similar evolution along those lines. I think all manufacturers will eventually move in that direction, so that to the pilot, the differences will largely fade away.

  34. There’s reports now that more software bugs have been found:

    This is related to how the two FCCs talk to each other, something that Boeing needs to implement this duplex approach to AoA integrity, and is something that the FCCs were never intended to do. That’s not especially encouraging.

    It’s also somewhat problematic. The EASA is very keen on AoA integrity, it’s mentioned it several times and dropped enormous hints that it’s looking for more AoA transducers and a proper triplicate approach to FCC design. So here we are with Boeing offering a cobbled together duplex design that, for the moment, isn’t working. Worse still it’s a Bug that Boeing didn’t find, the FAA did, in an audit.

    Which makes me wonder if this extemporised duplex design has any formal design to it, and any formal verification and testing. Because if not, the chances of the EASA accepting it could be vanishingly small.

    • Matthew, please take a breath and follow the source.

      This bug was found by and was reported by Boeing. Not discovered before because they are testing near-final software loads on an actual aircraft. It’s a startup problem, and is expected to take at least a week to fix, although that will be done concurrently with other tasks.

      Here are quotes from the Seattle Times:

      “Boeing has identified a new software flaw in the grounded 737 Max that will require additional work, possibly further delaying the plane’s return to service. The company alerted the U.S. Federal Aviation Administration and is notifying customers and its suppliers, it said in an emailed statement.

      The issue involves how software on the plane checks itself to ensure it’s receiving valid data, said a person familiar with the issue who wasn’t authorized to speak publicly about it. It occurs when the system is initially starting up, the person said.

      “The issue is in the plane’s flight-control computer software. It was confined to how it performs validation checks during startup and doesn’t involve its function during flight, the people said.

      The problem came to light when the latest version of the software was loaded onto an actual aircraft, according to one of the people. While it has been tested on planes in flight, most of the software reviews have occurred in a special simulator used by engineers on the ground.”

      • Rob, can you not see the issues here?

        1) the simulators they’ve using thus far don’t recreate the behaviour of the actual aircraft. They’re supposed to. How can any certification test data from these simulators be trusted? It’s not the first time they’ve been found wanting (trim wheel forces were wrong last time).

        2) Boeing seems to be using interactions with the FAA as some sort of free bug finding service, not just a regulator. This should be very embarrassing. If the Boeing team repeatedly get caught out this way, keep getting surprised, one can justifiably question their qualifications for doing the work.

        3) Some months back they got a sobering result when the FAA did a standard failed-noisy sensor test, resulting in an overload of the FCCs. These two test mishaps aren’t exactly encouraging news if one is worried about the completeness of Boeing’s software testing plan. It was almost as if they hadn’t got that standard noisy sensor testing in their own test plan.

        4) they’re still ploughing ahead with this fix despite the fact that regulators such as the EASA have been publicly doubtful that this is an appropriate thing to do. This is far from being a sure way to get a global RTS

        5) If the sims can’t recreate an aircraft accurately, and they’ve not got instrumented aircraft to do testing that way, what is the basis for recertification testing? Or even the certification test?

        The point is that where the world needs to see some sort of calm, authoritative response to the crashes we have instead been treated to several events that, and I’m being as kind as I think I can, are more reminiscent of “let’s try this and see if it works”. I have seen nothing thus far to suggest Boeing actually has a full understanding of their own aircraft (eg who knew the trim wheels might be unmovable?), a thought reinforced by the mysterious pickle fork failures on the previous model suggesting that they either don’t understand its structure, or their own production process quality, or both.

        Also there’s this US congressional(?) report suggesting that a full certification of the MAX (instead of grandfathering it) would not have produced a different result. Well that’s not very encouraging, suggesting that the MAX was as safe as could have been produced under the full certification regime extant in the USA.

        • Matthew, I’m nor aware that any of these allegations are currently true.

          1. The issue with the simulators was they could not replicate the extreme conditions of ET302. That has since been addressed. I’m not aware of any other problems.

          2. Not sure what this is referring to. The story about the FAA finding this bug is not true.

          3. The story about the FCC becoming overloaded was also not true. It was corrected in subsequent reporting.

          4. EASA has expressed concerns about the original classification of MCAS, They will conduct tests to answer those questions. If they are proven correct, that will change the rules for MCAS to be compliant. There are also a few people within the regulators who have raised objections to the concept of MCAS. The regulators themselves have been careful to not make any determination until testing is complete.

          5. Boeing must produce both qualified aircraft and simulators for certification testing. No regulator is going to allow a test otherwise.

          Trim wheels and pickle forks are not new issues. The wheels work well under normal conditions. The pickle fork cracks are similar to cracking issues that have occurred for many aircraft, including A320 and A380. Fatigue is an issue for all aircraft, it’s the thing that limits their life.

          It’s clear that you’ve formed an extremely negative opinion of both the MAX and Boeing. That in itself is fine, but we should try to ensure the evidence is as factual as we can reasonably determine it to be.

    • Matthew,

      Thanks for the link. The register does know about computers in a distributed architecture. So when they speak they should be listened to.

      They say the two FCCs failed to communicate. This caused other issues. Including a failure to properly monitor start-up.

      Nothing wrong with your post and the link.

      • The Register story is inaccurate. If you trace the sources, a Bloomberg article is the original source. This was quoted by the Seattle Times, along with additional background from Boeing. ABC News then ran a similar piece from those stories, and Register picked it up from ABC, but got some of it wrong.

        The Boeing press e-mail was sent to numerous news outlets, but some of them went further in their research. The Seattle Times is usually solid because they have many sources inside Boeing and will do their own background before publishing.

        It should be obvious that if it occurred in an actual aircraft, it was not part of the software audit. It may have been discussed in the audit progress meeting Boeing held in Seattle this week.

        Here is the original source:

        • In your view the register article is inaccurate.

          Read Steve’s post with regard to your posts. Take it in.

          It’s now 15 months since the Lion Air crash. Not one positive word from the regulators. Don’t you it’s time you accepted there is something seriously wrong.

  35. RealSteve, just a brief answer this time:

    Yes to your first two questions. One advantage of MCAS is that it addresses the small part of the envelope where it’s needed, but has no penalty for the rest of the envelope where it isn’t.

    On the 737 vs 757 issue, you hit the mark when you said airlines determine the market by buying 737’s, or whatever else they choose to buy. Manufacturers have to be responsive. Attempts by manufacturers to influence the market often don’t work out. 757 for Boeing, A380 for Airbus. Both great aircraft, but the market went in another direction.

    Lastly on the FBW, that is unquestionably the future, but it will be implemented in ways that feel more natural to the pilot. Bjorn did an article on the A220 hybrid Boeing/Airbus approach to FBW. The 777 may be a similar evolution along those lines. I think all manufacturers will eventually move in that direction, so that to the pilot, the differences will largely fade away.

  36. Intricate and over complicated plot. It looks like they started with one thing and finished with another. Too many lose ends. Can they all be tied together without some sort of deus ex machina. Will a Mcguffin serve the purpose?

      • Philip,

        Nah, I’m just a dilettante, an observer.

        But more and more, I’m beginning to wonder if the Max right now is a plot device, a distraction while something momentous is happening in the background. It’s just still too hard to believe that the Max is salvageable, despite all of the reassurances to the contrary. I’ve never seen anything like it. Boeing is being too secretive; it’s in some ways like the shell of an airplane they deceptively dragged out when they introduced the unfinished 787.

        Instead of feeling like they are sitting on putting the final touches on tweaks to what will be a reliable aircraft, it seems like a mess with way too many technical loose ends. And that is what we know. What we don’t know (as information steadily leaks out about the daunting task of quickly correcting Jerry-rigged corrections), seems even more ominous.

        So, I worry that all of this continued talk about the Max is just a distraction from something huge they might be planning in the background: the radical economic restructuring of Boeing which would includes government buyouts and reorganization.

        It’s hard right now for me to imagine a way out of this debacle. Let’s pray it is everything Rob says it is and not just smoke and mirrors.

    • This article may be slightly biased. Boeing orders have dropped precipitously but Airbus orders have declined slightly as well.

      Obviously no one will order the MAX while it’s grounded and there is still no certainty regarding regulator actions. But those decisions appear to be deferred for now. We’ll have to see what happens after RTS. It could go either way, that will depend on how the MAX is viewed after remediation.

      Both Airbus and Boeing orders have declined since the peak in 2014. In 2019, the lack of Boeing orders meant the number of total aircraft orders dropped by 818 over 2018, which is roughly half of the expected orders.

      • Yes, all orders went down from the 2014 peak, but Airbus almost did a 1:1 book to bill (1131 total, 768 corrected for cancellations, 863 delivered in 2019). That is not too bad in a weak market and taking into account AB is ramping up production to record levels. Boeing had <0 net orders and cannot deliver its most produced aircraft. They are just eating backlog. Even if the DB article is slightly biased, this is a bad situation for Boeing that is almost without precedent.

        • I agree, this situation can’t be resolved until RTS. It’s why RTS is so important. My point was that Airbus did not pick up the missing Boeing orders, they just didn’t occur at all. So decisions are on hold until this plays out.

  37. If the master caution light goes on and the plane does something to surprise the pilots, the pilots are trained to 1), switch off the autopilot and 2), switch off the auto-throttle, and take manual control of the airplane. Now presumably, it will be 1, 2, and then 3), hold the trim wheel, and then switch off the stab trim cutout switch? I don’t like that. I want at least a quick switch to kill the MCAS/STS system. Not kill the only trim motor for the stabilizer. Why the wiring change to not allow only the autopilot system commands to be shut down as in the
    previous 737’s?

    There are warning lights for “MACH TRIM FAIL”, “SPEED TRIM FAIL” which comply with FAR 25.672
    FAR 25.672 Stability augmentation and automatic and power-operated systems.
    If the functioning of stability augmentation or other automatic or power-operated systems is necessary to show compliance with the flight characteristics requirements of this part, such systems must comply with §25.671 and the following:

    (a) A warning which is clearly distinguishable to the pilot under expected flight conditions without requiring his attention must be provided for any failure in the stability augmentation system or in any other automatic or power-operated system which could result in an unsafe condition if the pilot were not aware of the failure. Warning systems must not activate the control systems.
    but, no “MCAS FAIL” light? Why not?

    Bad sensors, signaling automatic flight controls, with no failure indications, is a recipe for disaster

    FAR 25.672 (b)
    (b) The design of the stability augmentation system or of any other automatic or power-operated system must permit initial counteraction of failures of the type specified in §25.671(c) without requiring exceptional pilot skill or strength, by either the deactivation of the system, or a failed portion thereof, or by overriding the failure by movement of the flight controls in the normal sense.
    The Speed Trim System can be immediately counteracted by pulling on the flight control column, as one would, instinctively, to stop a speed trim runaway.
    Where is the “initial counteraction” of a failed MCAS runaway? Again, is it depending on the rewired Stab Trim Cutout switches, not any direct OFF switch?

    What other plane uses a “Speed trim system”, other than the 737? Why only the 737?
    The 737-Flight Crew Operations Manual says…
    “The purpose of the STS is to return the airplane to a trimmed speed by commanding the stabilizer in a direction opposite the speed change. The STS monitors inputs of stabilizer position, thrust lever position, airspeed and vertical speed and then trims the stabilizer using the autopilot stabilizer trim. As the airplane speed increases or decreases from the trimmed speed, the stabilizer is commanded in the direction to return the airplane to the trimmed speed. This increases control column forces to force the airplane to return to the trimmed speed. As the airplane returns to the trimmed speed, the STS commanded stabilizer movement is removed.”
    So, why does the 737, need stabilizer changes to maintain a constant speed, and no other planes has this? Is it to maintain proper column force?

    Another viewpoint says that the STS system is used to help keep the nose down during high thrust settings at low speed.
    Much akin to MCAS, but, this was posted in Nov 2016, referring to the 737-800.
    So, again, what is the reason behind the Speed Trim System on the 737? To stabilize pitch?

    The 737 seems to need a lot of automated help, to stay stable in pitch. Why?

  38. Richard, I’ll answer in reverse order.

    1. Most modern commercial aircraft have some form of automatic trim. It’s a normal function of the FCC. It may not be labeled specifically as such, as it is in the 737, where it was added in later generations.

    2. The STS system eases the pilot burden of maintaining aircraft trim under lower-speed conditions (several seconds after takeoff until Mach 0.6 or so).

    It slightly opposes the pilot-induced changes in pitch that would result in a change of airspeed. It favors the pitch that maintains the current speed for the current aircraft settings. This makes the aircraft easier to control, small motions of the column don’t result in pitch oscillation. It effectively lowers the sensitivity of the column to small movements, as well as compensates for passengers moving around, and minor wind effects.

    You’re aware that “pitch and power” settings can set the speed of an aircraft and are used during instrument failures. The pitch and throttle (inputs) are adjusted to get the desired speed (output). This is that same idea, only the FCC knows the throttle position and speed (inputs) so it adjusts the pitch (output).

    It’s similar to what MCAS does, except the intent is different. MCAS slightly opposes the pilot to offset the change in trim brought on by high AoA. In either case, the automatic adjustments to trim are not large enough to countermand the pilot or create a control problem.

    3. For MCAS, the initial counteraction mode is deactivation. Since MCAS is only active when the pilot is intentionally flying with column back at high AoA, there cannot be an instinctive response cutout as there is for STS or MT in level flight.

    4. The warning lights for STS and/or MT are controlled by the FCC, to alert the pilot that STS and/or MT are not active when they are expected to be. The FCC has relinquished control due to some detected problem. They are not active in a runaway event, or to indicate a problem with the trim system. The FCC doesn’t have enough information to govern trim, and has stopped. This is why the runaway trim checklist doesn’t mention the trim failure lights.

    That same functionality would not have helped the MCAS accidents, the FCC kept control and did not relinquish it. That said, since MCAS engages only momentarily at high AoA, it would be good to have a positive operation indicator, similar to the ABS, traction, or stability control lights in your car.

    5. Restoration of the NG switch system would be a good thing, to disable the FCC control of the stabilizer but maintain pilot electric trim switches.

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