UPDATE: Cowen & Co issued a revised note today, with new language concerning simulations of the MCAS flying characteristics. Boeing is not urging sim training. Rather, it is urging regulators and pilots to go to sites where MAX MCAS flying characteristics may be witnessed and understood. Cowen tells LNA it misunderstood what Boeing said.
May 10, 2019, © Leeham News: In a sign that Boeing is confident it’s on track with the fix of the MCAS for its 737 MAX, the chief financial officer of the company Wednesday and Thursday made the rounds in New York and Boston with aerospace analysts and key institutional investors.
Coming out of these meetings is news that Boeing will support simulator training for pilots to fully understand MAX handling characteristics, one analyst reports.
Greg Smith gave the financial analysts Boeing’s latest thinking about progress in returning the MAX to the skies across the globe. He also said Boeing is using the production slowdown (from 52/mo to 42/mo) to allow suppliers, notably engine maker CFM, to catch up from their own delays and strains. The suppliers maintained the 52/mo rate.
Spirit Aerosystems said it hopes that CFM, which has been running two-three weeks late with engines–will return to rate 52 in June. This is faster than suppliers were told by Boeing when the rate was cut in April. At that time, June’s rate ramp up was goal was 47/mo, with 52 in August and 57/mo in September. Boeing last year planned rate 57 in June this year.
Analysts issued notes following their meetings with Smith. Here are summaries of some of them, directly quoting the notes:
BA’s first potential milestone in trying to get MAX grounding lifted is its FAA certification test flight and meeting of the FAA with international regulators scheduled for Dallas on May 23. Boeing will not be in attendance to assure that it isn’t influencing discussions; and while the meeting could lead to lift of the U.S. grounding, the FAA also could require additional testing and documentation. Furthermore, European regulator EASA and China are expected to move separately to evaluate allowing the resumption of MAX service; and it’s unclear what their lag vs. the FAA will be.
Deliveries also may be impacted by need to reshuffle delivery positions, with possible required configuration changes if customers where grounding is extended, i.e. China, won’t be able to accept them.
BA hasn’t focused on the NMA since the Ethiopian crash, and given NMA’s business case hasn’t closed, it likely won’t be launched at the Paris Air Show in mid-June. Moreover, BA views NMA as an effort to derisk its next small aircraft. BA also is considering that 777x EIS could be delayed from 2020 if the FAA decides to adopt more stringent certification procedures. Hence, it’s considering trying to sell more 777-300 ER’s to avoid a production dip if the 777x is delayed.
Boeing stated it is holding daily calls internally regarding the 737 MAX situation, which includes a lane for outreach to each existing and planned customers. There is a lot of focus on delivery profile in those conversations, in terms of which airlines are capable of taking which deliveries and when. Boeing stated there has been a lot of movement in the skyline, though nearly entirely related to ability to accept deliveries vs. anything else. The company also suggested that MAX deferrals that have occurred since the grounding were by airlines that were likely to have made those changes anyway. Customer liability discussions will start once the aircraft has returned to service; and can include a variety of items outside of cash, including PDPs or delivery positions.
Boeing will stay at 42/month until the aircraft returns to service. It suggested it could start to increase the rate again at that point, but also pointed to a desire to clear the ramp of currently parked planes before quickly growing rate. It also stated it wants to increase rate in increments while maintaining stability; and not go back to where it was previously when at 52 but with a disrupted supply chain. The company is not committing at this point to how the production rate plan looks on a multi-year basis compared to what it was prior to the MAX grounding, given the many moving pieces in that equation, though it did have to submit a production plan to auditors to generate the estimated $1.0bn of incremental cost it added to the block in 1Q.
We get the sense Boeing may have ended up waiting till fairly late into 2019 or even very early 2020 to make the previously planned break to 57/month on account of supply chain disruption. The company stated the condition of its own facility is already significantly better today than at the time of the grounding as a result of these efforts.
We are looking at May 23 for indications on the path forward. This FAA meeting should include representatives from over 50 regulatory bodies and—as previously reported—the FAA intends to share more about the methodology it will use to determine when the 737 MAX can re-enter service. This does not guarantee that the FAA will have approved Boeing’s flight control software modifications by then, though we cannot rule that out either. The FAA certification flight for the new software has not yet occurred though comments on the Q4 call suggested to us that it would be soon and we have no reason to change that view. This process is separate from the Joint Technical Authorities Review, in which nine non-US entities are reviewing the FAA’s approval process for MAX flight controls. That review began last week and is expected to last 90 days but regulators need not wait for its conclusions to lift the grounding.
There are still several re-entry into service scenarios. . . . We believe one purpose of the May 23 meeting is to set forth a global roadmap for bringing the MAX back to service since we think the FAA, most other regulatory agencies, aircraft manufacturers, and airlines all see value in the existing certification regime. Despite that shared goal, global regulators will need to be satisfied that they have done everything required—and show the public in their countries that they have done everything required—to ensure the aircraft is safe, and so we do not take for granted that everyone will re-certify the aircraft simultaneously. Boeing management believes, however, that its engagement with global regulators thus far has been constructive.
Boeing will work to restore its brand. Management is quite aware that it has to shore up confidence in the company and the 737 MAX among the public, regulators, and other players in Aviation. With regard to the MAX, airlines seem likely to take the lead since they are the direct link between the product and travelers, though Boeing intends to play a key role in supporting them. We do not yet know what form this will take and the situation is unusual. On the earnings call, however, CEO Dennis Muilenburg highlighted the critical role that research shows pilots playing in inspiring trust among travelers and it does not sound to us like that view has changed. Meanwhile, the company continues to engage with US lawmakers and global airlines and regulators, including bringing them to simulators to demonstrate and discuss the software upgrade.
We found our meeting with Boeing management to be more encouraging than not. To start, there remain a host of unknowns that the company faces including the MAX’s return to service, government inquiries, and knock-on effects from the accident. Having said that, we found a degree of optimism on the part of management as dialogue with regulators and customers is progressing, specifically around getting the 737 upgraded and back in the air, which could potentially occur over the coming months. Of particular importance to them is the upcoming May 23 meeting between the FAA and other aviation authorities, since it may lay out a path towards certifying fixes and removing the grounding.
The MAX certification is progressing with the May 23 FAA event being a key watch item. Following the most recent earnings call on April 24, there was a view that an effective FAA handover was imminent of the software fixes on the MAX via a certification flight, which has yet to occur. However, management pointed out that there was no delay in the process and that the FAA has been engaged with Boeing on a consistent basis. Moreover, it was even noted that such a certification flight is not a prerequisite to returning the aircraft to service. Nonetheless, that process does seem like it will move forward over the coming weeks, with the most important milestone now being the May 23 meeting between the FAA and global aviation officials. Following this meeting, there is the potential for a clearer path forward relating to a removal of the grounding, certifying of fixes, and necessary training, all through a more consensual path. We find this encouraging given the opportunity for clarity and a return to service consistent with our late 2Q19 / early 3Q19 assumption.
Boeing would slowly clear inventory levels, which we estimate will be in the ~150 aircraft range by mid-year, as it along with the airlines would not be able to process the large volume given logistical constraints (e.g. pilot availability). And while there was no number provided by management on maximum monthly 737 deliveries, we believe the 70-100 range is appropriate based on Boeing’s / Airbus’ history with the 737/A320.
Will passengers fly the MAX again? Management obviously believes so, and we think so too. Management acknowledged a tough path ahead on regaining trust of the aviation community and are finding ways to tackle it through customer outreach, public campaigns, and so on. In addition, they are bracing for a level of demand pressure at the outset when the MAX returns to service. They even drew parallels to the 787, where there were a degree of headwinds initially, albeit noting different conditions with the MAX. In our opinion, and utilizing our knowledge of covering airlines, most passengers are unaware of aircraft types when flying, making an effective ban of the MAX difficult to give credence to.
” This process is separate from the Joint Technical Authorities Review, in which nine non-US entities are reviewing the FAA’s approval process for MAX flight controls. That review began last week and is expected to last 90 days but regulators need not wait for its conclusions to lift the grounding.”
Hmm, I sense a rather flat learning curve on the side of Boeing and the FAA here, on who is going to restore confidence in the 737 MAX. They can’t bluff their way out this time.
I don’t see why both can’t go hand in hand.
US can lift and any others can follow (there are some smaller carriers in a degree of distress)
Longer term aspect may well take longer term.
If EU and China not happy then they can continue grounding.
We get to see both sides case at that point
Shouldn’t the question be if passengers gladly will board American, United or Southwest 737 MAXes if the aircraft is still grounded outside the United States?
No, we don’t pay any attention to what anyone else is doing.
A few will be nervous, this is the age of taking selfies while you back over a cliff, fall off a spire or go into a river looking for a Pokeman thingy.
For me it’s a matter of risk.
It is surely uncertain that passengers in the US will be ignorant or uncaring of continued groundings outside the US. Given the mainstream media coverage and on-going Federal investigations, many might ask “why us?”. Such an unusual situation is certainly not going to do anything to dampen down the media coverage.
If they do boycott the aircraft, the impact is that MAX operations in the US would descend into chaos which is a lot more expensive than a continuned grounding.
Another risk aspect is that if (heavens forbid) there were actually another accident there would be hell to pay. Actually, that should be “sound engineering processes forbid”, but that seems to have been an unfashionable prayer in recent years.
I did ask LNA whether it were possible that the DoT could override the FAA and prevent the MAX returning to the skies. No one seems to know, but if the DoT (or indeed the DoJ) have developed any initial impressions as to what’s gone wrong, they may be forced to intervene. It seems madness on the part of the FAA and Boeing to proceed as if “everything is normal” when it demonstrably is not.
This is turning into a genuine shell game. The a/c is unfit to fly, even seasoned pilots are expressing a reluctance to fly it, yet the “feel good” P.R. persists. Bandaids on an unworthy flying a/c is being drowned out, IMO by a nationalistic instinct. Boeing, vs. a European builder seems to be resonating through out the community. We’ll have to wait and find out how the other aviation overseers feel about the airworthiness of the Max. And, as well the DOJ has thus far been silent on criminal proceedings. The truth may very well will out, but this guy will not fly on any of the Max’s.
I don’t know how its gotten to be demonstrably not.
Certainly aspect to look into, but MCAS Rev 2.0 looks to fully correct the disaster 1.0 was.
The NG has a long history of no issues, while the process and why changes were not made to bring up to curretn standards, we hove 4 or 5 thousand NGs flying just fine.
If you want to introduce chaos then ground all of them.
Or we can look at this with a discerning eye, deal with the immediate issue, get the MAX back into the air.
It clear that pilots can’t fly a FBW aircraft in direct modes as well.
So we can ground all FBW aircraft as well.
The groundings probably have to be lifted in unison, else Boeing could be in deep trouble outside of the USA. If the FAA restores the MAX to the skies, but EASA or CAAC doesn’t like their reasoning, that means there’ll be a difference of opinion between the FAA and EASA / CAAC / whoever.
That in turn means that there will be additional work to be done, but it seems very unclear to me how that work could be actually done, especially as the FAA’s and Boeing’s default position would be that that work is unnecessary.
Worse, if FAA, EASA and CAAC disagree then Boeing could be in the awkward position of having conflicting engineering directions being forced on them. Boeing can’t afford to have different versions of the MAX for different regulator’s jurisdictional areas.
Given that the problems with the MAX seem as much managerial as anything else, Boeing could be being pressed to make wholesale changes to how their company works by a non-US regulatory body. Like that’s going to happen…
It can be that requirements in training will differ between airworthiness authorities. I think Boeing redid the whole analysis and documentation package for the Aircraft, introduced all the Required software solutions and defined SB’s for future incorporation for the hardware found needing improvement. Boeing most likely has come up with different levels of training programs. So the FAA can argue that US pilots need one type of training (15 min iPad) and others can pick another training package (full flight simulator +4hr session).
Is the CFO the usual suspect for this or is Boeing trying out a New Spokesperson?
I noticed that too. They are making sure that its only financial aspects that get discussed- for Boeing thats the only new information they want out there.
Meanwhile flight safety story at FAA Seattle office and Boeing is being told – by others
“In 2012 the Department of Transportation’s Inspector General sent investigators to interview Federal Aviation Administration (FAA) technical staff in Renton, where engineers working under manager Ali Bahrami were responsible for certifying new planes developed by Boeing.
The [IS] investigation substantiated employee allegations that FAA managers did not always support efforts by their technical experts to ensure Boeing complied with safety rules. It found “a negative work environment” where safety engineers feared retaliation “for attempting to hold Boeing accountable.”
Meanwhile the rest of the world is noticing the absence of complete transparency in Boeing’s handling of this matter, and are forming opinions as to how trustworthy the company is.
I wonder how much interaction there has been between the company and the EASA, CAAC, etc. Afterall it’s their opinions that now matter, not the FAAs. The very US centric messaging coming out of the company seems designed to placate shareholders more than anyone else, so I suspect that there’s been very little communication to bodies beyond the FAA.
This risks a detrimental response elsewhere in the world.
Also Boeing ought to remember that part of the value proposition for an aircraft is its resale price later on in life. That could end up being zero if it stays on the ground outside the US.
Yes, it’s a turnabout for Boeing to now ‘urge’ simulator time for pilots. I just hope that BA taking this position will shift the airline bean counters to realize that the cost to the bottom line of a disaster is much higher (though much, much smaller risk) than buying a simulator (c. $15M each) and budgeting pilot time.
I realize that margins are under some pressure now, but US airlines at least are very profitable. The cost to marginally improve safety is slight in the current revenue era.
With regard to the recent Gates article identifying 4 issues that may have not complied with FAA requirements, would the 23 May meeting take these on board or instead focus solely on Boeing’s MCAS modifications? If the latter, can the FAA entirely reasonably & legally re-approve despite the suggestion that these other 4 issues may exist? I’m guessing these 4 could be items that would ordinarily merit an AD rather than grounding.
As an aside on training, interesting article on training schools this week at https://www.aerosociety.com/news/back-to-flight-school/
I think its a very relevant aspect, what I don’t know is how relevant the 4 items are in the large picture.
Clearly the 737NG has flown massive hours with no issues in those areas.
And they make trade offs all the time. RR put aircraft at risk with the Trent 1000 with too optimistic forecast.
And MD-11 (Swiss) had the wiring catch fire that was a known issue for doing just that.
There has to be some trade off between an aircraft that carries one persons safe no matter what and an efficient transportation system.
I would like to see the details and the risk analysis of the 4 items.
Re the NMA delay and the short development timeframe Boeing was already suggesting, an interesting article at https://www.aero-mag.com/airbus-aircraft-wing-manufacturing-developments/ indicates Airbus are working on enablers to shorten the wing developmentcycle from 8 years to 5 years. If Boeing is ahead of Airbus on similar enablers perhaps their short timeframe is genuinely achievable.
What is the availability of simulator time, and how many existing simulators can emulate the MCAS action ?
Will this be a further impediment to full return to service for MAX aircraft ?
Would any airline start flying without simulator time for the pilots, given the statement “Boeing will urge pilots to take simulator training. ” ?
Boeing should get boxes made quickly to make existing 737NG simulators working as acceptable 737MAX simulators and design an extensive pilot training program for the MAX’es with a good set of failure modes which include the MCAS system as well.
Assume Boeing owned FlightSafety International will be the main center for this and can see which pilots need extra training to meet Boeing min requirements and charge for it.
I believe only Boeing’s own internal simulator has the MCAS simulation capability.
Most 737 simulators do not even cover MAX at all.
Considering MCAS did not officially exist until it crashed a plane, none of the simulatiors have it. I suppose they can use runaway trim to simulate MCAS.
MCAS did not exist in Pilots world, it would be in the MAX Simulator (will need to be reprogrammed)
A MAX simulator has to have it even if no one knew about it (interesting aspect of doing a stall and finding out!)
It will be is in the tech manuals as well.
There are some MAX simulators hitting the airlines now.
You can probably have a MAX mode for an NG Sim though the fidelity is wrong as the display panes are different.
The AOA display and AOA disagree light would be there though not quite the same location as well.
Yes. The changes are here
The big difference is the 4 new 15.1 inch displays. In the central 4 inch gap between display 3 & 4 has been squeezed a smaller gear lever along with a lock override button, alternate nosewheel steering selector, gear indication lights and placard speeds. The ISFD is above the gear panel. The flap position indicator is now part of the electronic displays. The autobrake and MFD selectors and brake pressure gauge have moved down to the Forward Aisle Stand (in between the FMCs). The PFD/MFD transfer switches are on the lighting panels in front of the control column.
The Forward Aisle Stand has been extensively changed as the lower DU on the NG has now been integrated into the large format displays (follow this link for more details).
The overhead panel is very similar to the NG. Differences include:
Elevator Jam Landing Assist panel on lower left of Aft Overhead Panel
A SPOILERS light on the Flt Controls Panel
PSEU light removed and replaced by MAINT light
Engine panel has three new amber reverser lights
Landing light switches reduced for LED lights (also on later NGs)
I believe Air Canada already has CAE’s 7000XR simulator for the MAX.
What is right or wrong doesn’t seem to form the basis of decision making at Boeing. All that determines the process is what Boeing senior management think they can get away with.
– Can we avoid any culpability for the crashes?
– Can we do the absolute minimum that is acceptable to get the aircraft flying again?
– Can we minimise cost and time as the most critical target?
– Can we pressure FAA/US Govt to do our bidding?
– Can we separate the recertification of the MAX to speed up re-entry from the deeper process issues?
Simply they are gaming everything rather than considering the fundamental reasons for certification. Certification is not about getting a piece of paper, it is about proving as best they can the safety of all aircraft systems in all conditions. That bit seems to have been forgotten about by senior management. Remember they got the piece of paper before…
So what have we learnt today? Well Boeing has lost the battle to avoid simulator time. A battle they fought because it would have adverse financial implications for them. The fought to avoid costs in spite of the clear safety implication.
I thinks the stability problem can be fixed. What worries me most is the MAX certification process, questionable FAA objectivity and time pressure that seems to have led to design short cuts & self approval. And Boeing stubborn denials, the re emerge of previously killed 737 grandfathered requirements and design and authorities and OE working shoulder to shoulder to keep costs & development time down to match the competitions. Sometimes it feels safety was the #3 priority.
Keesje, The stability problem is obviously central to the MCAS safety issue. If Boeing has changed the parameters to MCAS activation to now have it under perform when it should trim the nose down, then we have a higher risk of aerodynamic stall. And we’re left hoping Boeing has tuned the stability recovery correctly. They are the only ones with the data, unless NASA and the FAA are in there helping out. For some reason, they changed the trim speed in the original design. Why, we don’t know. Will pilots be able to find out for themselves, where the limits are, in the simulators? Will any flight departments investigate this more, or just use ‘canned’ routines to train their pilots. Will Boeing clue them in, on what portions of the flight envelope to concentrate on?
There is a massive difference between stability and a known operating characteristic.
Pitch up at stall is not a stability problem. Any pilot that was trained would (should) have zero issue with it once they know its there.
You don’t operate at aerodynamic stall so its not like its going to come into play. If it does you have stick shaker and alarms.
MCAS turns it back to what the NG did. Frankly doing so was a tragedy that could have been avoided as you could easily deal with it from a known stick shaker alarm perspective.
I had a Jeep that would not respoond to coutner steering (for those folks who never drove a care that did not have you point it steering)
Ity would snap back if you counter steered to a stop (normal) as it was a bit top heavy and narrow, the suspension loaded up.
The answer was to start turn back the other way before you stopped.
Desirable? No. It only was a factor when you were in a skid (which you should not be) but while vicious, it was fully controllable.
It just took a bit of training to learn how to do it.
If a pilot could not handle that then they should not be flying (though it is arguable that many should not as many can’t seem to handle even a routine problem without turning it into an emergency)
“Rather, it is urging regulators and pilots to go to sites where MAX MCAS flying characteristics may be witnessed and understood.”
There are two ways to read this:
The cynical take is that Boeing would like pilots to have simulator training but since there are not enough simulators requiring it will result in a slow and incremental return to flight. So instead the pilots should go watch an MCAS movie.
The charitable take is that they want pilots to do more than take some e-training and have determined, via experimentation, that watching an MCAS incident being handle is sufficient to upgrade an NG pilot. And who is to say, medical students train by watching a surgeries.
No, obliviously you could watch a movie anywhere.
Y9u would have to go to a site that had a MAX sim.
Whoee, is that splitting hairs or what. Shoot, why not climb in and do a stall recovery? You spend all that money to send em there, feed em, transport them to and from the hotel to the Sim and they just get to watch (you are right by that logic a movie would be fine)
Line em up, take all of 60 seconds per pilot and all is good.
Boeing continues to pile on the manure for sure.
How do you turn MCAS OFF? Pilots still can’t? They still have to resort to switching the entire motorized trim system off? And hope they have enough time and energy to trim manually? As in the failed Ethiopian Airlines 302 accident. That’s still their best hope, if the MCAS system has a runaway event? If Boeing is now suggesting that level D simulator training is required, then why not fix the toggle switches?
This would give pilots more of a fighting chance. Previous 737’s had the two toggle switches actually do separate actions. Has anyone heard anything about the FAA or Boeing looking into a separate toggle switch for MCAS? I’d think it would be easy to implement and give the pilot control. Unless there is some reason Boeing doesn’t want the pilot to have ultimate control? https://www.krdo.com/news/national-world/faa-reviewing-longstanding-emergency-procedures-used-in-737-max-crashes/1077105385
Why not fix the errors that have been put into MCAS now? Do they think, if they don’t fix them, then they don’t exist for a court trial? It would be an admission of guilt to fix the MCAS faults now?
See what Aviation Week has to say, does this sound like an aircraft you would wish to be flying in…..
WASHINGTON—A simulator session flown by a U.S.-based Boeing 737 MAX crew that mimicked a key portion of the Ethiopian Airlines Flight 302 (ET302) accident sequence suggests that the Ethiopian crew faced a near-impossible task of getting their 737 MAX 8 back under control, and underscores the importance of pilots understanding severe runaway trim recovery procedures.
Details of the session, shared with Aviation Week, were flown voluntarily as part of routine, recurrent training. Its purpose: practice recovering from a scenario in which the aircraft was out of trim and wanting to descend while flying at a high rate of speed. This is what the ET302 crew faced when it toggled cutout switches to de-power the MAX’s automatic stabilizer trim motor, disabling the maneuvering characteristics augmentation system (MCAS) that was erroneously trimming the horizontal stabilizer nose-down.
In such a scenario, once the trim motor is de-powered, the pilots must use the hand-operated manual trim wheels to adjust the stabilizers. But they also must to keep the aircraft from descending by pulling back on the control columns to deflect the elevator portions of the stabilizer upward. Aerodynamic forces from the nose-up elevator deflection make the entire stabilizer more difficult to move, and higher airspeed exacerbates the issue.
The U.S. crew tested this by setting up a 737-Next Generation simulator at 10,000 ft., 250 kt. and 2 deg. nose up stabilizer trim. This is slightly higher altitude but otherwise similar to what the ET302 crew faced as it de-powered the trim motors 3 min. into the 6 min. flight, and about 1 min. after the first uncommanded MCAS input. Leading up to the scenario, the Ethiopian crew used column-mounted manual electric trim to counter some of the MCAS inputs, but did not get the aircraft back to level trim, as the 737 manual instructs before de-powering the stabilizer trim motor. The crew also did not reduce their unusually high speed.
What the U.S. crew found was eye-opening. Keeping the aircraft level required significant aft-column pressure by the captain, and aerodynamic forces prevented the first officer from moving the trim wheel a full turn. They resorted to a little-known procedure to regain control.
The crew repeatedly executed a three-step process known as the roller coaster. First, let the aircraft’s nose drop, removing elevator nose-down force. Second, crank the trim wheel, inputting nose-up stabilizer, as the aircraft descends. Third, pull back on the yokes to raise the nose and slow the descent. The excessive descent rates during the first two steps meant the crew got as low as 2,000 ft. during the recovery.
The Ethiopian Ministry of Transport preliminary report on the Mar. 10 ET302 accident suggests the crew attempted to use manual trim after de-powering the stabilizer motors, but determined it “was not working,” the report said. A constant trust setting at 94% N1 meant ET302’s airspeed increased to the 737 MAX’s maximum (Vmo), 340 kt., soon after the stabilizer trim motors were cut off, and did not drop below that level for the remainder of the flight. The pilots, struggling to keep the aircraft from descending, also maintained steady to strong aft control-column inputs from the time MCAS first fired through the end of the flight.
The U.S. crew’s session and a video posted recently by YouTube’s Mentour Pilot that shows a similar scenario inside a simulator suggest that the resulting forces on ET302’s stabilizer would have made it nearly impossible to move by hand.
Neither the current 737 flight manual nor any MCAS-related guidance issued by Boeing in the wake of the October 2018 crash of Lion Air Flight 610 (JT610), when MCAS first came to light for most pilots, discuss the roller-coaster procedure for recovering from severe out-of-trim conditions. The 737 manual explains that “effort required to manually rotate the stabilizer trim wheels may be higher under certain flight conditions,” but does not provide details.
The pilot who shared the scenario said he learned the roller coaster procedure from excerpts of a 737-200 manual posted in an online pilot forum in the wake of the MAX accidents. It is not taught at his airline.
Boeing’s assumption was that erroneous stabilizer nose-down inputs by MCAS, such as those experienced by both the JT610 and ET302 crews, would be diagnosed as runaway stabilizer. The checklist to counter runaway stabilizer includes using the cutout switches to de-power the stabilizer trim motor. The ET302 crew followed this, but not until the aircraft was severely out of trim following the MCAS inputs triggered by faulty angle-of-attack (AOA) data that told the system the aircraft’s nose was too high.
Unable to move the stabilizer manually, the ET302 crew moved the cutout switches to power the stabilizer trim motors—something the runaway stabilizer checklist states should not be done. While this enabled their column-mounted electric trim input switches, it also re-activated MCAS, which again received the faulty AOA data and trimmed the stabilizer nose down, leading to a fatal dive.
The simulator session underscored the importance of reacting quickly to uncommanded stabilizer movements and avoiding a severe out-of-trim condition, one of the pilots involved said. “I don’t think the situation would be survivable at 350 kt. and below 5,000 ft,” this pilot noted.
The ET302 crew climbed through 5,000 ft. shortly after de-powering the trim motors, and got to about 8,000 ft.—the same amount of altitude the U.S. crew used up during the roller-coaster maneuvers—before the final dive. A second pilot not involved in the session but who reviewed the scenario’s details said it highlighted several training opportunities.
“This is the sort of simulator experience airline crews need to gain an understanding of how runaway trim can make the aircraft very difficult to control, and how important it is to rehearse use of manual trim inputs,” this pilot said.
While Boeing’s runaway stabilizer checklist does not specify it, the second pilot recommended a maximum thrust of 75% N1 and a 4 deg. nose-up pitch to keep airspeed under control.
Boeing is developing modifications to MCAS, as well as additional training. Simulator sessions are expected to be integrated into recurrent training, and may be required by some regulators, and opted for by some airlines, before pilots are cleared to fly MAXs again. The MAX fleet has been grounded since mid-March, a direct result of the two accidents.
There is something especially galling about plunging as low as 2,000 ft during the roller coaster recovery procedure simulation (also known as yo-yo…).
I have commented for some time the issue is not MCAS, that can be corrected.
Its the lack of ability to use manual trim when needed.
More so, why ha this been allowed for 40+ years?
People have gotten their undies in a twist about the dangerous killer MAX (when we have seen an FBW aircraft close to as dangerous) when in fact this goes bock a long ways.
Clearly the manual trim system needs a power assist.
Getting wigged out about the MAX so called dangerous instability misses the issue entirely.
MCAS may be tamed but a run away trim is still lurking like Jack the Ripper.
And now this pops up.
It is in line with Peter Leme wiring diagram and I never thought I would see a safety that did not break the primary power.
A relay can fry contacts and stay engaged.
From the Seattle Times article. “A veteran Boeing 737 test pilot said that all Boeing planes have two such cutoff switches, not just the 737. And both he and American Airlines Captain Dennis Tajer, a spokesman for the Allied Pilots Association who flies 737s, said they could think of no existing procedure that called for flipping only one of the switches.” Wouldn’t you want to flip the left cutout only, if the pilots bubble gum got caught in the yoke switch, so you could fly the plane via the A/P trim. And flip the right cutout only, if the A/P went crazy, but, you still wanted to maintain trim control via the electric yoke mounted switches? If MCAS goes crazy (as it has), there is no MCAS cutout switch. You can’t have electric yoke powered trim and MCAS off, so you’re stuck with playing tug of war with MCAS every 5 seconds. Or, put out the flaps to hopefully turn off MCAS. MCAS has no OFF switch. The only way to turn MCAS off is to disable the electric trim system and go to full manual trim wheel. Why can’t they include a 79 cent toggle switch to simulate a flap down setting to shut off MCAS, and allow full electric trim control from the yoke?
I think part of the problem, is getting stuck in a “Don’t change anything that could affect training, and therefore cost” mantra.
Sometimes you do need to change things ! If there is a possibility that a change may save lives, in my book, it’s a no-brainer, make the change !
I would change the switches back to NG style, one to cut off autopilot trim, and the other to control electric trim, even if the probability is remote that the aircraft will reach a situation requiring their use, at least you give the pilots a chance.
“they could think of no existing procedure that called for flipping only one of the switches.” but clearly, there have been two fatal hull loss incidents where such a procedure could very well have saved all 346 souls.
Time for a new procedure !
As it is now, Pilots will be either in a tug of war with MCAS ever 5 seconds for control of the trim, or turning off the electric trim system all together and then forced to try and use the manual trim wheel. In the ET302 flight, it looks like the young, foreign, 250 hour pilot correctly identified the Left AOA vane indication, and asked the captain about turning off the stab trim cutout. It appears they did cut out the stab trim, but, then later were out of options with elevator control and unable to use the manual trim system, so they had to turn on the MCAS monster again. There was no other options open to them. There was no way (other than possibly adding flaps, which isn’t a real option), for them to turn off MCAS and return electric trim. An MCAS cutout switch would have given them that option. So, why isn’t an MCAS cutout switch now part of the ‘fix’? The MCAS monster may be less of a threat, with the proposed changes, but, it’s still not under the Pilots ultimate control.
If a pilot had an MCAS cutout switch,wouldn’t he/she be better off just switching the dammed thing off all the time?I am confident that there would have been 2 fewer crashes and as a passenger I would prefer them to do that.
Grubbie, That’s a very good question. How many times has MCAS activated in the past? Zero, 5 times, every flight? We don’t know. If you ripped out MCAS, then how does the risk profile of the planes handling characteristics change? Will it handle just like a 737-NG? If you believe MCAS has a stall prevention function, avoiding a sudden, surprise stall that can’t easily be recovered, or happens a lot. All questions that make you wonder why someone changed the speed of MCAS’s trim to high speed in the approval process. We hope it’s a benign condition and would be easily recoverable by quick pilot action, but, I have no idea. There is a pitch up tendency because of the engine’s position and size, but, I haven’t heard how much more of a risk this is. Just that MCAS is there to help prevent “it” and Boeing doesn’t seem to want to rip MCAS out. They don’t even want to have a toggle switch to turn it off. The only other airplane with this MCAS function seems to be the Military KC-46 tanker. (highly modified B-767).
My own question.
MCAS is not the matter, it’s just the tip of the iceberg.
1) They decided a critical system must be fed only by a single sensor (which was faulty in this case) with no double check or a filter for clearly wrong readings. Same reason for the Turkish 737 which went down at Schiphol
2) Said system has no proper interface or warning
3) They didn’t fit an extra switch to disengage only automated trim inputs. You want to kill MCAS? You get no electric trim at all (it’s like: your PC gave you an error? Switch off the whole house!)
4) Backup procedure (manual trim wheel) is clearly not working in real life
5) Backup of the backup (the rollercoaster) is not even taught in training and anyway won’t work if you don’t have altitude.
Problem here is that, apart from MCAS, the whole 737 fleet is designed this way. I’m scared by the fact that Boeing and FAA are trying to convince the world a software tweak will solve the issue.
There’s a whole design to question here, and more important, their whole safety culture.
If they’re trying to get away with it on the Max, who can guarantee for the rest of their production then?
I’d ground the whole 737 fleet at this point…
And still it seems to get even worse:
“No one has yet to conclude that the sole cause of this was this function on the airplane,” Sinnett said
But if MCAS was not there would Flight 610 have crashed ?
“You’ve got to understand that our commitment to safety is as great as yours,” Sinnett said in the meeting. “The worst thing that can ever happen is a tragedy like this, and the even worse thing would be another one.”
And then there was ET302, and still no rush to ground the aircraft, and still the relentless push to get the MAX back in the air as soon as possible.
I just don’t feel that safety is the greatest commitment here, just my perception, but so far I see nothing to change that.
The max commitment (no pun intended) is for corporate profits while threading the safety needle.
“At the hearing, Elwell was also critical of Boeing’s handling of a cockpit warning light that would have alerted pilots of a problem with the plane’s angle-of-attack sensors, which MCAS uses to determine when to engage. While Elwell said the warning light was for the sake of maintenance, not flight safety”
“maintenance, not flight safety”
So the AOA disagree warning light is not for the pilots, it’s for the maintenance staff ?
It appears on the PFD does it not ? But surely you don’t want to clutter up the PFD with data that would just distract the pilots, maybe it only appears in a special maintenance mode when the aircraft is on the ground.
I’m not sure Elwell is correct, on https://www.pillsburylaw.com/en/news-and-insights/us-senate-holds-hearing-on-b737-max.html it is stated:
“According to Elwell, the 737 MAX 8 is a fly-by-wire aircraft, and MCAS was designed to supplement the speed trim system. Elwell indicated the purpose of MCAS is to give the pilot the proper feel with the fly-by-wire yolk, making it feel like the Boeing 737 NG”
He was I believe a US Airforce pilot, and an American Airlines pilot, so I can’t understand why he would make a statement that the 737MAX was a fly-by-wire aircraft.
Also I suspect it’s a yoke, and not a yolk, too much technology the spellchecker probably ‘upgraded’ it.