Lessors, airlines seek 1 year lease extensions in MAX groundings

June 26, 2019, © Leeham News: Airlines and lessors are making plans to extend leases by up to one year as the Boeing 737 MAX grounding drags on with no end in sight and carriers scramble to cover their routes, LNA is told.

Shortly after the MAX was grounded, on March 13, airlines began extending leases on airplanes that were to be replaced by the MAX up to six months.

This was until the September-October timeframe.

Now, with estimates that the Federal Aviation Administration may not be ready to lift its grounding order until then—and other regulators may come later—airlines see a need for another lease extension.

Lessors are not interested in another six month extension, however, LNA is told.

New flaw found

This information emerged before news of yet another flaw in the MAX, discovered by FAA inspectors flying a MAX simulator. Though the new flaw is unrelated to the MCAS, the discovery may further delay a return to service. Reuters was the first to report this story.

The one-year lease extensions may further impact how quickly Boeing can return to service the grounded and undelivered airplanes that now number nearly 600 aircraft (almost 400 grounded, about 200 undelivered).

Boeing continues churn out MAXes at the rate of 42/mo. These are going straight to storage at four sites in Washington State plus San Antonio (TX).

There are already some estimates it will take Boeing into 2021 before the undelivered backlog is cleared.

64 Comments on “Lessors, airlines seek 1 year lease extensions in MAX groundings

    • I guess the FAA now test all combinations of Take off weight, center of gravity, Thrust derate, Tambient, failed components including computers/engines, rate of climb, percipation and so on. The amazing fact is that they actually found problems after Boeing had done its own full testing of their updated systems after 2 accidents and found a problem that should have been found in the initial certification testing by both Boeing and the FAA.
      The lesson from this would be a much more FAA detailed certification testing scheme everybody has to follow in the future.

      • Well, and this is only what they found in the simulator. Now what if they fix this, then start flying an updated MAX and find that it doesn’t behave like in the simulator, because Boeing has tweaked the simulator also to mask (enhance) the rapidly moving center of lift problem.

        • The FAA test pilot did a good job, just wonder how many problems Boeings test pilots identified when debugging MCAS 2.0 and what combined failure modes they dare to induce and test on the aircrafts.

          • If the FAA tests everything on their checklist and it looks good .. but, then accidently find out, that holding the intercom button for 3 seconds causes the airplane to burst into flames. Do they certifiy the plane as OK to fly, since it passes all the regulatory testing? Do they have a copy of the software to be able to test out every “IF” conditional branch? They missed huge, glaring items last time. No limits to Automatic Nose Down commands. Only one AOA sensor as input etc. It doesn’t fill me with confidence to hear it’s been FAA certified safe to fly, according to regulatory testing. I’d like them to publish the tests they ran and the results they found.

          • The next question is what hoops will the 777-X need to jump through for certification. 2021 EIS might even be optomistic.

    • I wonder if the FAA was walking through their test procedure guidelines (AC 25-7C)


      and came across this and found that the 1 second rule didn’t work for the MAX MCAS 2.0system? Maybe that’s why MCAS 1.0 was so agressive?
      Section 25.145(a)
      requires that there be adequate longitudinal control to promptly
      pitch the airplane n
      ose down from at or near the stall to return to the original trim speed. The
      intent is to ensure that there is sufficient pitch control for a prompt recovery if inadvertently
      slowed to the point of stall. Although this requirement must be met with power
      off and at
      maximum continuous thrust or power, there is no intention to require stall demonstrations with
      thrust or power above that specified in §
      25.201(a)(2). Instead of performing a full stall at
      maximum continuous power or thrust, compliance may be a
      ssessed by demonstrating sufficient
      static longitudinal stability and nose down control margin when the deceleration is ended at least
      one second past stall warning during a one knot per second deceleration. The static longitudinal
      stability during the ma
      neuver and the nose down control power remaining at the end of the
      maneuver must be sufficient to assure compliance with the requirement.

  1. Hi Scott,

    I presume that if the airlines are forced to take additional 1 year leases, they will attempt to recover the costs from BA at some point.

    What does this mean for deliveries though, if an airline now has more NGs on lease for a further year, will they defer their MAX deliveries once the MAX has been cleared to fly again ?

    Is there a cross-over point at which it makes more sense to park the leased NG, and fly the MAX ?

    Will BA just continue to build at rate 42, and continue parking the aircraft somewhere ?

    Another obvious question, if this new issue is not directly MCAS related, but rather related to the microprocessor involved in the speed trim system, is it likely we’ll also see an AD to ‘upgrade’ software on the NG series, or potentially a CPU hardware swap ?

    I wouldn’t have thought that the MAX modifications would downgrade the processing power to less than the NG, so I would think the issue may be down to the extra software required for MCAS is potentially overwhelming the existing processor.

    Confidence level monitor:
    FAA + 1 %
    BA – another 5%

    • At this rate there won’t be any Boeing to recover costs from. If Boeing does enter Chapter 11, that’s pretty bad, but if it actually collapses that’s a catastrophe; no design authority, no Boeings fly…

      • These days they might take GE down with them. Funny but BA’s health might be a major concern to AB.

        • I agree with all that.

          At the end of the day all us engineers in all fields suffer reputational damage when such a high profile, well known engineering company like Boeing has very big problems. We all need Boeing to properly right itself and restore their reputation.

          Including Airbus. I think they’re **** scared of a Boeing collapse, because Boeing’s presence in the market is a back pressure on Chinese expansion into the market. If Boeing disappears overnight there’s a massive gap in the market and China would rush (well, years) to fill it. And if Airbus acted to fill it themselves the monopoly would not pass unchallenged by regulators. I think the Boeing Airbus duopoly suits Airbus very well indeed. It also suits Western governments very well too.

          So, would Uncle Sam nationalise Boeing to save it if required?

        • No way. If the 787 debacle , which cost 10s of $billions didn’t bring Boeing down then this won’t either. All those max orders are like future money in the bank.

          • Not to mention all the shares they’ve bought back, which they could sell again if necessary!

    • I assume getting the supply chain to reduce the pace of delivery would incur massive compensation, hence ‘the supply chain stays at 52’ mantra. 737 is BA’s most profitable program? Maybe margin is around 20% then? Then rate 42 means BA have a tangible asset to morgage, or show creditors, equal to the cost of taking 52 shipments a month. When they ramp up over 52 the parts in storage get used up before the supply chain goes to a higher rate. Or at least I imagine that is the plan

      • @martinA

        The supply chain staying at 52 game is madness if the production is retained at 42. Do they really mean that all componentry will still be delivered at this higher rate? There are four potentially massive problems drawing just in the assembly.
        First on recertification they have to bring all aircraft up to spec and prepare them for flight, all 600+ of them
        Second they have the massive storage headache of all the sub components when Renton is designed as a near JIT facility with very limited space
        Third they have to ramp up the production above 42 to 52 plus and ‘feed in’ the stored parts in some beautifully choreographed but very tricky process that has ‘cock up’ written all over it.
        Fourth they have to reestablish a delivery programme when many airlines are now looking at medium term solutions and are just as likely to defer than accept in the immediate term.

        I do not envy Boeing staff this challenge, it will still be having ramifications in 3-4 years. By that stage what rate will AB at? A320 at 70? A220 at 15? So nearly double that of BA with a lot of higher margin A321 variants in the mix.

        • Airbus is known to ruin profit margins, I suspect the A321NX /A321LR problems to eat away profits still the volume of regular A320neo’s should more than compensate that. I can imagine the cabin customization problems Airbus will run into with the A321XLR when each airline will customize it with own funished equipemnt for long haul operations and their bits come in late and its quality might not be accepted by Airbus Reciving Inspection. It can be the A380 cabin nightmare again unless Airbus forces customers to standardized cabin solutions as on the A350.
          Just waiting for Qatar Al Baker to be an early customer for A321XLR…unless Airbus already told them to waint until they have delivered sn 200 of the XLR before they can get their first delivery.

  2. It’s interesting info, thanks Scott and Leeham is superb. My question is, is there anything deeper to be read into with this news, aka are more MAX re-certification delays are coming? Or is this just an airline safety precaution?

    My meaning is, do the airlines have a hunch or inkling about re-certification taking longer than we, the public, currently anticipate? My impression is the public is anticipating a re-entry into service sometime between mid-September (early) to December (late). But definitely *sometime* before 2019 year-end. But does this leasing news mean FAA re-certification odds are actually quietly slipping until 2020?

    Publicly, I don’t expect airlines (particularly US ones) to say or do anything to anger Boeing, except gentle prods perhaps. And I presume not publicly scheduling the MAX until 2020 would be something that angers Boeing, because it is such a public condemnation of the plane’s re-certification chances…so we just see these incremental delays, like United bumping to September, not much rocking the boat. But privately, what are the airlines saying? Are the airlines actually thinking further MAX re-entry delays are inevitable past what they’re indicating publicly? Are we to read the tea leaves from this leasing development, and assume FAA recertification may not happen until 2020 at the earliest? (of course meaning MAX service doesn’t normalize until 2021 or maybe even 2022?)

    (and just would also like to say thanks, our Leeham subscription is some of the best money we spend)

    • Why do you believe that the customers have to be worried about displeasing Boeing?
      If anything, it should be the other way around, even if Boeing doesn’t seem to see it that way, yet!

  3. Two quotes from the Reuters article which are indicating that Boeing is still not being honest, with anyone!

    “The risk was discovered during a simulator test last week and it is not yet clear if the issue can be addressed with a software upgrade or will require a more complex hardware fix, sources with knowledge of the matter told Reuters. ”

    “Boeing said in a securities filing late on Wednesday that the FAA has asked it to address through software changes a specific flight condition not covered in the company’s already-unveiled software changes.”

    Ok, maybe the sources with knowledge of the situation are incorrect but I know who I am more likely to believe.

    It’s back to Jon Ostrower getting all sorts of info on the 787 and Boeing nonetheless trying to tell the world his information is incorrect, until they were finally forced to admit he had correct information and reliable sources.

  4. Not much else really to say. I would still like to know why MCAS 1.0 is overwhelmingly aggressive. There must be a reason.

    With regard to the latest discovery, as reported by Pablo, above, and by FlightGlobal: It’s a case of still trying to use software to hide the truth. In the end this is going to be one heck of a piece of software. Indeed a magical piece of software.

    If Boeing add bit the bullet and put a couple of horizontal fins on the airplane to keep the nose down, then it would be in flight test by now and ready for service by year end. Welding a couple of fins on the current fleet would be a small amount of work.

    As it stands, year end at best before return to service. But the regulators will have to accept that a software fix is sufficient. I won’t fly it. Not with just a software fix.

    • I might add that if fins are added then it must be combined with a hard limit to AND settings of the stabiliser. I f done together they will ensure the elevators remain operative. But they must be done together.

      • The nose up issue was found to be manifested at low speed as well as high. Possibly in a turn.

        Ergo, Boeing made MCAS more aggressive due to the fact you need more movement to get affect at lower speed.

        I have not seen it clarified if it was a all or nothing approach (reduced affect at higher speed)

        From Ethiopian crash it seems not as they were at higher speeds.

        the real issue and questions is the process and stove piping at Boeing as well as the issues with FAA and inspector reporting to Boeing now.

        Flight test did not know what software was doing, software was not real world tested (murder board) to see what affect it had.

        Flight test and the flight engineers should be hand in hand with each other located at the same place and daily discussions.

        If you make an assessment and you change things, then you go back and review all the data that went into it to see how that had bearing on it.

        That was not done, they just kept kludging it and the base review was never redone.

        We have also seen that they do not use real world failure data for the AOA, just the self failures, not bird strikes, ramp hits etc.

        This is beyond gross stupidity that is in the FAA bailiwick (though Boeing should have been looking at it, its not supposed to be a game of what can we get away with assessing risks)

        Very much like Fukushima where they cut off the Tsunami history short of the last big one (and those records existed and they knew about the previous one to the point one town still had markers that were a do not build past here elevation line)

        As I have noted, they could not have hashed it up worse if they tried.

  5. This may not be obvious, so may I point out that this statement does not mean that the MCAS issue is solved? It only means there is a second one on top of it.

    What we don’t know yet is how the two are related, but my best guess is that it too has to do with the stability of the plane and its trim systems.

    What I also find quite notable is that we finally arrive at the first mention of “hardware changes”. To me this sound like “we’re actually quite sure that we can’t fix this bird with software only”.

    Now it’s getting quite interesting. If the FAA arrives at the conclusion that the Max has overlapping trim and stability issues (which I think is the case) they may end up demanding substantial changes at major systems. This could turn into a logistical and financial nightmare for Boeing.

    Some time ago I proposed to cut the Max production to a minimum, at least half. I would repeat that now. Oh, and they should not forget to get the R&D of the NSA going asap.

    • Both the CBS and the FlightGlobal report are confusing. But on the basis of the FlightGlobal report, they were testing trim stabiliser runaway.

      Trim stabiliser runaway is a separate issue. It’s about the electric motor that drives the stabiliser. If the electric motor causes a significant AND stabiliser action then it must be switched off and manual trim used. But we know manual trim doesn’t work above 250 knots.

      Boeing said they are going to use a software fix to prevent the electric motor from causing excessive AND stabiliser actions. But what if the electric motor does not respond to the software?

      This I think is the latest issue. They tested the trim stabiliser runaway but the software fix didn’t cause a sufficient response.

      I am though doing a lot of interpretation of what CBS and in particular FlightGlobal have said.

      I think the stabiliser should be prevented from excessive AND actions using hardware. A stop bolt of somekind.

      • Bandaids overlaid upon bandaids overlaid upon bandaids.

        Where does it end ?

        • I was just going say the same thing. When you rip the band aids off you are going to have a big ulcerating sore.

    • That ship sailed in 2011. NSA, will not help now. Even if the NSA design was done and Boeing began offered it today they will not see revenue from it for 7 years. And not get to 50/year for 12 years, best case. Boeing must get the MAX back. Once it does they have time and cash. Without it Boeing is a different company.

      • You have to understand the technical language.

        Reference is runaway stabilizer not flight modes.

        Ego, there is an issue in the relay logic that allows a higher level of risk than is (now) accepted.

        As there were changes to several aspects of how the control column cutout worked as well as the cutoff switches themselves that is a likely possibility.

        One flaw I saw as that cu tour switches did not kill the main power.

        In the Industry I worked in, an E-Stop did two things, it signaled the PLC via a contact it was pulled, but it removed the control power. Physicality no flaw could re-power or fail to power.

        Best is the main power removal that eliminates welded contacts

        • You have hit one of several nails on the head here. In my opinion the last line of defence should be a simple hard wired switch amd cable which does’t go through any computer. THIS AIRCRAFT WAS NEVER DESIGNED FOR FBW.

      • jbeeko, bleak as you outlook for an NSA is, it’s just possible that it is Boeing’s best option from here on.

        It can probably bail out of all those undelivered MAX orders (painful though that would be). It could probably somehow weedle it’s way out of commitments to extant grounded MAX customers. Yes, it’d be without revenue from single aisle aircraft for a few years, but at least that’d be a fairly certain, quantifiable outcome. It might also bankrupt them, but at least that can be calculated and dealt with in advance.

        As things stand with the MAX there’s is no quantifiable outcome, every attempt so far to quantify it has been wrong, they’re now way into unprecedented territory with no guarantee of a successful exit. That’s an almighty great risk, and there’s no practicable way to manage that.

        Other factors: it’s not like their customers can really go anywhere else at present, Airbus are fully booked on A32x and can’t do anything to help. Boeing could conceivably get away with swapping MAXes for NGs in the interim, bring on a NSA, and get it into service before Airbus can sensibly accomodate any disgruntled MAX customers in large numbers.

        We are seeing signs that airlines are looking for a Boeing exit strategy. Southwest were found to be sniffing round the A220 family. Ok, so the A220 is not necessarily a direct replacement for all MAXes, but at this point in time you can buy and fly A220s, seemingly to great passenger satisfaction. If you have to have more slots, aircraft and crew to have the capacity you need, that’s attainable.

        If a pure-Boeing airline were to contemplate changing supplier, there’s a lot of motivation to do so at the moment. Coming up with a strategy – any strategy – to dissaude defections to another OEM is now essential for Boeing.

        However, all Boeing seem to be doing is sitting there being proven wrong again and again on a return to flight date. That’s not a strategy. That’s the opposite of a strategy.

          • All I’ve said really is that Boeing has carefully worded contracts, there’s no end in sight for the MAX’s problems, Airbus has a full order book for the foreseeable future, Boeings MAX customers are in a bind and looking to their own futures and Boeing aren’t doing anything demonstrably positive to reassure them that there is a place for Boeing in those futures.

            Calling that “partisan nonsense” is a bit like shouting furiously at a passerby at a football match who’d said “they’re not doing very well” when your own team was busily kicking the ball into their own net time and again. For the record I’m a big admirer of the old Boeing, but not the new one.

            What matters is whether or not Boeing fully recognises that this unprecedented situation could easily become an existential threat to the company. Judging by the company actions so far, I don’t think they do. I think they’re taking survival for granted, and no company should ever do that. At the end of the day quality really does matter, and across the whole company Boeing has a quality problem (space, military, civil aircraft). Inmarsat walked away probably due to perceived quality, the tanker is a FOD nightmare, and there’s a full blown crisis in civil aircraft. If they fail to address their quality problem starting at the top they are guaranteed to go bust, eventually.

        • Isn’t that Airbus can’t ramp up production rate of A320 because of lack of sufficient engines cuantity on the market? Isn’t it what’s holding Airbus from opening another FAL?

    • I also suspect a more deeply routed problem here. Not necessarily related to MCAS itself, but more as to why there was a need for MCAS in the first place.

      I wonder if the MCAS “fix” has now caused a return to one of the original performance issues, be it the original factor or, my suspicion, the second issue resulting in the extreme MCAS revision.

      • Aero Ninja, the question “why there was a need for MCAS in the first place” has many answers. As they Japanese are fond of saying, if you ask “Why?” enough times you’ll actually get the actual, definitive, root-cause answer.

        If you do that for MCAS, you’ll end up with “Boeing’s management don’t really know what they’re doing”.

        The fact that MCAS Fix#1 seems to have failed in very nearly the most embarassing way possible, i.e. whilst an FAA pilot was trying it out in a sim (and not during specification, design, implementation, debugging, unit test, bench test, integration test, and their own sim test) prompts one to ask “why?” several times again. And I think I’d get the same answer…

        Thank goodness it wasn’t being tried out on a real aircraft. As things stand, I suspect that all FAA pilots are now extremely reluctant to even begin to contemplate doing an actual flight test.

        Interestingly, the Japanese aren’t necessarily perfect at applying this principal to themselves. TEPCO, the company that ran Fukushima, basically invited disaster upon themselves and the whole of Japan, instead of asking “Why?” enough times about their own competency to operate the plant. The answer they seemed to stop at was, “Because currently it’s profitable”. Hmmm.

  6. @Philip, Gundolf

    It looks like MAX airframe has significant problem during flight as well as with high speed as with low speed – and Boeing tried but couldn’t manage a hardware fix, so they went for software which flawed and unreliable.

    From 23/06/2019 Seattle Times:

    “Engineers observed a tendency for the plane’s nose to pitch upward during a specific extreme maneuver. After other efforts to fix the problem failed, the solution they arrived at was a piece of software — the Maneuvering Characteristics Augmentation System (MCAS)”

    “The lack of smooth feel was caused by the jet’s tendency to pitch up, influenced by shock waves that form over the wing at high speeds and the extra lift surface provided by the pods around the MAX’s engines, which are bigger and farther forward on the wing than on previous 737s.”

    “The flight-test pilots had found another problem: The same lack of smooth stick forces was also occurring in certain low-speed flight conditions.”

  7. This is turning into a logistical nightmare, there is a chance that something could go wrong with managing all the complex processes involved in getting the fleet back into the air.

  8. Oh dear, Is the MAX a safe aeroplane to fly? Doesn’t appear to be…

  9. I mentioned this before, I will repeat it here.

    Boeingspeak seems to be pushing the optimistic dates as far as returning the MAX to service. If they mention third quarter, they already know it is the fourth. If they mention end of the year, it won’t be until last year.

    As reference, I give you the 6 787 delay notifications, starting September 2007 and going on until December 2008. Need I mention the “rollout” of the empty shell on July 8, 2007? Of course there is also the Paris Air Show of 2009, where first flight was predicted to occur in the next two weeks. Accurate!? But of course not! A bit over a week later, the next delay was announced.

    Who really believes anything they say concerning scheduling these days?
    No wonder the lessors want 1 year, and not only 6 month, extensions.

    • You might keep it relevant to the program at hand, 787 was a different animal with only the battery issue at any commonality with MAX

      • Aero Ninja’s comment is relevant. It’s the same people giving out time estimates… Aircraft don’t announce anything.

  10. Was the Lion Air accident primary cause due to the Angle of Attack (AOA) Sensor being at fault? Setting off the chain of events with MCAS?
    If so, it would be the 2nd bad AOA, in a row, newly replaced on an almost brand new plane. Or, maybe the 1st AOA was good and some other
    problem in the Air Data computer system is/was faulty? If Boeing gets the OK to install MCAS 2.0, the 737-MAX fleet starts flying again, and
    then the final Lion Air accident report comes out, saying that the 1st AOA sensor that they fished out of the trash, works fine. Boeing
    now has fixed a problem with a bad MCAS design but, maybe not the problem that caused Lion Air to crash. I’m assuming Boeing has better access
    to the Lion Air accident investigation than most of us. Maybe they know this and are scanning their Air Data computer system top to bottom, looking
    for any possible errors? Something was wrong for a while with that planes air data system. Maybe it was built on a Monday and someone didn’t tighten
    a connector properly, but, we really don’t know at this point. I hope Lion Air’s final accident report sheds some light on the root cause. Of course,
    I’m hoping Boeing figures out that true fly by wire (FBW) systems require three AOA sensors and much more redundancy than the system they have for MCAS.
    Even with three AOA sensors, two can fail at the same time as witnessed by an Lufthansa Airbus 321 flight in the past.

    From http://avherald.com/h?article=47d74074

    An occurrence was reported where an Airbus A321 aeroplane encountered a blockage of two Angle Of Attack (AOA) probes during climb, leading to activation of the Alpha Protection (Alpha Prot) while the Mach number increased. The flight crew managed to regain full control and the flight landed uneventfully.

    When Alpha Prot is activated due to blocked AOA probes, the flight control laws order a continuous nose down pitch rate that, in a worst case scenario, cannot be stopped with backward sidestick inputs, even in the full backward position. If the Mach number increases during a nose down order, the AOA value of the Alpha Prot will continue to decrease. As a result, the flight control laws will continue to order a nose down pitch rate, even if the speed is above minimum selectable speed, known as VLS.

    This condition, if not corrected, could result in loss of control of the aeroplane.

    The EASA requires as immediate emergency action that the flight crew operating manuals must be amended with a procedure to keep only one Air Data Reference Unit operative and turning the other two off in following cases:

    – the aircraft goes into a continuous nose down pitch movement that can not be stopped by full backward stick deflection
    – the Alpha Max (red) strip completely hides the Alpha Prot strip (black/amber) without increase in load factor
    – the Alpha Prot strip rapidly changes by more than 30 knots during flight maneouvers with increase in load factor while autopilot is on and speedbrakes are retracted

    In this type of situation, how would a 737-MAX fare? No AOA disagree light would turn on. The pilots would note MCAS activating? (is there an MCAS activation light
    on the pilots panel???). They would then have enough time to hit the stab trim cutout switches, because MCAS 2.0 isn’t as agressive and is limited. But, they are
    now back to the manual trim wheel, because MCAS 2.0 still has no OFF switch. In the Airbus, I believe they can switch off 2 of the 3 air data systems, to see if one
    still functions correctly. In the 737-MAX, can you turn off one or the other air data system? (I haven’t researched). How often does this happen, and how serious a
    problem is this? Airbus with it’s full FBW redundancy, seems to be better prepared than the 737-MAX, which doesn’t requrie full FBW certifcation for it’s MCAS system.
    Should MCAS require full FBW certificaton? Is MCAS a FBW system?


    This new wrinkle for the 737-MAX is now showing up. (Thank you Pablo for posting this link)

    • My understanding is that the current 737 failure/safety related design
      is based on systems “bifurcation”. i.e. Two independent systems.

      Introducing a link between the two “Lobes” like plausibility checking for AoA ( left, right) and similar sensor kills that concept for good.

  11. I think what the FAA is doing is making Boeing go through the entire certification process again and with a much higher level of scrutiny. Considering what has transpired I think this is compeletely fair. They should get no grandfathering benefit.

  12. Nice to see the FAA finally taking an interesting in doing its job – at the upper level and letting the flight folks actually do their job.

    Is this a one off and back to business as usual once this is over or do we get a change of culture and process to stop it forever?

  13. If deliveries don’t resume till next year and production rates are still 40+ per month, Boeing will over 400 planes in storage plus the grounded plane. How long can Boeing sustain this rate ?

  14. If this is not an MCAS issue, is this an issue with the NG as well? I hear it is something about the trim toggle switches not having quick enough authority over the HStab. I think the FAA now have to declare the NG is fine in this regard, or not, now that doubt has been cast on this system.

    • Amen! I believe it is indeed the NG response lag – if similar to that of the MAX – that is the elephant in the room.
      Scott, has your ear to the ground picked up anything on this?
      If that is indeed the case a soft or hard ware solutions will be required for essentially ALL operating 737s, which is a problem of a significantly higher order of magnitude.

  15. Computers don’t keep up with airplanes, airplanes keep up with computers.

    A walk down memory lane. When I was at University I was given access to CDS Cyber 200. State of the art. I was full of myself. It filled a room and it could perform calculation at 1 MIP. I was in ore.

    My compuer chip on my mobile runs a 1000 times faster than a CDS Cyber 200. Times have changed.

    So to come to the point. The computer chips on the 737 MAX are fast enough. So what is the real issue.

    The computer sends a command. The relevant control surface responds but the computer doesn’t properly analyse or wait for the effect of the response before sending another command.

    It’s called latency. Bjorn addressed it in his articles when he said pilots are taught to do small adjustments and wait for the response.

    Computers have to do the same. Small adjustments and wait for the response.

    The software becomes difficult if the airplane is sensitive. So if an airplane is sensitive in pitch then the software becomes difficult. The margins become small. The same applies if a pilot is flying the airplane.

    So it’s not about computers keep in up. It’s about knowing how the airplane responds to command. Sensitively or instability is central to the knowledge required.

    So to the same question. What is the sensitivity of the 737 MAX in pitch? Or to use the other words, what is the instability of the 737 MAX in pitch?

    We keep being told there isn’t a problem with regard to stability. Instead, we are now being told the computer chip can’t keep up to address stability. That is believeable if the computer chip is circa 1970s.

    Today, computer chips can keep up. Indeed they need to wait for the airplane to respond in the same way pilots need to wait for a response

    Seriously. We are being given crasy explanations

    • I’d heard that they are using the 80286. That’s an 1980s chip from Intel. It’s not fast in any modern sense.

      Using antique CPUs is surprisingly common. NASA had to scour the world for pristine 8086s to keep the Shuttle flying. The F22 program had to do a lifetime buy of Intel i960s before the F22 prototype had even flown. Goodness knows what ancient heap of silicon Airbus use in their FBW, but it’s not going to be a Qualcomm 850 snapdragon… The Eurofighter Typhoon project had to port all their flight control software to new hardware because the old hardware went obsolete, and that was a major piece of work. The A220 has a brand new FBW system, so that alone probably has a decent chip inside it.

      So I’m afraid there is a real likelihood that they really have got a chip that’s too slow for what they’re now asking of it.

      Here in the UK any processing platform offered into a military project is supposed to have twice the compute power and memory to allow for this kind of thing.

      I don’t know if Boeing has such a design rule. If not I bet they now wish they did.

      • The CPUs used are fast enough and fully deterministic to do the task set.

        The issue is modern programmers that have unlearned to program from a fully groked problem definition in an efficient way.
        Improvements in CPU speed and complexity have mostly been turned into trashing ever growing resources and “waiting faster”.

  16. Going back many years I believe the Lockheed Electra was allowed to operate with a modified flight envelope after its whirling problems.
    Perhaps Max needs a similar solution?
    Not an aeronautical engineer, but have always thought that the canard was a very elegant solution to simple pitch control.
    If the Max solution is deemed to need a mechanical fix which I have always believed a possibility..perhaps a canard could be a solution.

    • Well that would be cool, 737 with Canards.

      Of course you would have to change the whole front of the aircraft.

      Or you can fix the problem and not hang more stuff on the airframe?

      Oddly they can perfectly control totally unstable fighters but we have a problem doing that on the 737? Hmmm..

      Perhaps wait for the actual details?

      • They added FBW for the 737 spoilers for relatively minor reasons…ie reduced stopping distances amoung them.
        It’s seems they overlooked vital stability controls that were more important. If the spoilers can use it ,why not the stabilisers? Probably far too late to upgrade though.

  17. A CNN article seems to point to testing the failure modes of the flight control computer. Maybe something is left ‘normally closed’ in a circuit rather than ‘normally open’ if a power failure of the CPU happens? Why are they so secretive about these testing results?

  18. This kind of thing is not normally necessary for the public to have confidence in the industry, and its commercially sensitive information. But when the regulator’s competency has been publicly challenged, the only thing they can do is to make sure everyone knows they’re (finally) doing their job.

  19. The 321NEO looks like gaining momentum with orders and conversions from 320’s to 321’s. AB should look at how they could increase 321 production.

    Not sure how quickly and by how much can AB increase A220 production but fast tracking a modest range (~2500Nm) A220-500 could take pressure of the A32X production line?

  20. “The one-year lease extensions may further impact how quickly Boeing can return to service the grounded and undelivered …”

    How do lease extensions “impact” the return to service/delivery rate?

    I see no cause path here.
    Customers extending leases is _indicative_ of delays in returning the 737MAX into service.

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