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Boeing 737 Max Recertification Testing - Finally.

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Boeing 737 Max Recertification Testing - Finally.

Old 23rd Nov 2020, 03:50
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MAX with or without MCAS operative compliant....

"Existing FAA regulations (14 CFR 25.21, 25.671, and 25.672) allow for use of stability augmentation systems (such as MCAS) in showing compliance with FAA handling characteristics requirements. The 737 MAX airplane with MCAS operative is therefore compliant."

"The outcome must show that the airplane is capable of continued safe flight and landing after single failures and any failure combination not shown to be extremely improbable (14 CFR 25.1309)."

"With MCAS inoperative, the Boeing 737 MAX is capable of continued safe flight and landing and is therefore compliant with 14 CFR 25.671 and 25.1309."

Good luck to MAX pilots (and passengers).....
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Old 23rd Nov 2020, 17:16
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»Harry Stonecipher once boasted after merger with MD that he deliberately shifted Boeing's longtime culture "so it's run like a business rather than a great engineering firm."«

Especially when you remember that it was *MD* that gave us the DC-10, which crashed in Paris (killing 346 -- ironically the precise sum of victims of the two MAX crashes) even though a previous incident had identified the cargo door as the certain cause of absolute DC-10 disaster one fine day.
But MD & the FAA were in bed together, so no serious action was taken.

Sound familiar?
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Old 23rd Nov 2020, 17:19
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Anyone up for an ignorant question?
Now I’m reading articles in non-specialist press citing respected aviation writers saying that forward engine placement, etc. causes the MAX to pitch up excessively when power increased. Yes, they seem to use “unstable” and “stall” in the same breath.

But I thought there was nothing particularly unstable about the MAX *provided* pilots had received adequate training – which was the whole point of MCAS: so Boeing could flog the thing to penny-pinching airlines wishing to *avoid* that training and put their NG pilots straight onto the flight deck.

Yours confused.
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Old 23rd Nov 2020, 19:10
  #484 (permalink)  
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Originally Posted by VFR Only Please
But I thought there was nothing particularly unstable about the MAX *provided* pilots had received adequate training
Stability (or lack of it) is a function of aircraft design. No amount of crew training can alter that.
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Old 23rd Nov 2020, 20:57
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Let me put that more clearly then. The aircraft is what it is (all are) but whether you can Handle what it is depends, among other things, on your training. That's why they installed MCAS: so the airplane wouldn't feel any different than the NG; so Boeing could market it as a no-type-training-required airplane.

That great sailor of the skies, aircraft designer and journalist Peter Garrison is quoted below as saying that placing powerful engines further forward on the half-century-old 737 concept was "destabilizing in the sense that the more nose-up it is, the bigger the forces tending to make it more nose-up.” I assume he's also referring to lift created by the nacelles, though he doesn't mention that here (beware of incomplete quotations).

So my question, as clearly as I can word it, is: Suppose Boeing had never devised MCAS and merely required pilot training to prepare crews for the Different Pitch Characteristics of this new 737 version. Would there then have been anything inherently more challenging about flying the MAX than the NG or other versions?
Because a lot of press coverage at least implies that the MAX, without MCAS, would be a trifle Stall-Happy.
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Old 23rd Nov 2020, 21:35
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VFR, the boundaries of acceptable manual flight characteristics are defined by regulation: CS/FAR 25. The regulations are well founded on many years of research and previous experience; i.e. failure to meet requirements, training would not be a solution for normal operation.

The 737 Max did not meet the requirements in two areas, low and high speed / turning flight, flaps up; thus the need for technical intervention.

The Max deficiency was not so extreme that the technical system required the highest integrity ( for the handling characteristics ). Thus a dispensation for deficient flight handling with failure might be granted, but the degraded safety margin would have to be mitigated with crew awareness, speed, trim, and/or limited by exposure time - land at suitable airport / continue to destination.

The latter point may be part of EASA's concerns - re actions / training.
EASA Decision not to adopt FAA AD

Training is not a panacea; because we are humans with limited capability.
Training is not a solution for system deficiencies.
If an accident report recommends more training, first identify the 'system' deficiency.
Perhaps the latter reflects differences in thought between FAA and EASA / Canada.

Last edited by safetypee; 23rd Nov 2020 at 22:26. Reason: PS
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Old 24th Nov 2020, 00:39
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safetypee, I think you have not addressed the question VFR actually asked. It is not a question about manual flying or about whether training could compensate for a system problem.

The panel of experts assembled by the FlyersRights group in the pending FOIA lawsuit - or some of those people at least - have publicly questioned the same point. Is the MAX, if it is the same as it was produced in fact BUT without MCAS, more prone to entering a stall?

As I read VFR's question, reference to training was in a different context: MCAS supposedly obviated any additional training, because when it worked properly it made the airplane operate the same as earlier variants. Without MAX, some other training would have been needed (isn't this referred to as "differences" training - and that is not limited to manual flying, is it?).

As just SLF/atty I cannot even fake understanding all of the detailed insights into workings of safety factors and safety processes, but I see the question by VFR (and it parallels the same or very similar questions others have raised) is a lot closer to something deserving a plain English response. (No irony intended; many times chastised for extra wordiness, here I am asking for plain English....is this the time to say "hat, coat.....?)
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Old 24th Nov 2020, 10:29
  #488 (permalink)  
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Willow, 'Is the MAX, … without MCAS, more prone to entering a stall?'

It would be very surprising if the Max was 'more prone' given that the original certification for flight with failure was judged acceptable. MCAS does not change stall characteristics, but primarily improves awareness when approaching the stall with increasing stick force.

Do not confuse pre-stall awareness with the flawed assumption of pilot ability in identifying a system failure - deficient design, engineering, certification. The accidents demonstrated that reliance on pilots for identifying MCAS failure and mitigation was ill-judged, but showed nothing about stall handling.
Then who judges stalls, certification pilots or 'experts' who may not have stalled the Max sans MCAS; and then where is the documented support for these judgements - before and after the accidents.

As a by-stander, the legal challenge appears more about challenging the FAA's credibility - competence in making these judgements given recent history, particularly with the absence of supporting documentation.

The FAA has to regain public trust, first overcoming the legacy of previous misjudgements. Then explain in layman's terms the reasoning behind new judgements - certification education, communicating and explaining residual risk. This is a daunting task, so far lacking substance, and which (cynically) might be hidden under the cover of a chaotic political situation.
Not so for the overseas regulators.

One difficulty is that this debacle defies simple explanation - plain English or not, it involves interwoven judgements without definitive solution or precedence. All that we might expect are improvements, with supporting explanation of judgements and risk.

Keep your hat and coat, but use a brightly coloured umbrella; shelter from the rain and you should be better seen by traffic when crossing the road.
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Old 24th Nov 2020, 15:05
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Disagree, Safety.

Do not confuse pre-stall awareness with the flawed assumption of pilot ability in identifying a system failure - deficient design, engineering, certification. The accidents demonstrated that reliance on pilots for identifying MCAS failure and mitigation was ill-judged, but showed nothing about stall handling.

- It's really hard to identify a system failure or anomaly if you do not know it is there!!! And what it is supposed to do.
- What other gizmos are in the plane that were not in the previous versions?
- Where was mention that the trim cutout switch wiring was different than previous models?

What Boeing did and the lack of FAA actions in the certification process as to crew procedures related to MCAS still gives me chills. GASP!

Last edited by gums; 24th Nov 2020 at 15:08. Reason: grammar/typo
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Old 24th Nov 2020, 15:34
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EASA proposals for Max - revised AD

"The EASA Proposed Airworthiness Directive requires the same changes to the aircraft as the FAA, meaning that there will be no software or technical differences between the aircraft operated by the United States operators and by the EASA member states operators"

"However, EASA’s requirements differ from the FAA in two main respects. EASA explicitly allows flight crews to intervene to stop a stick shaker from continuing to vibrate once it has been erroneously activated by the system, to prevent this distracting the crew. EASA also, for the time being, mandates that the aircraft’s autopilot should not be used for certain types of high-precision landings. The latter is expected to be a short-term restriction."

"EASA has also agreed with Boeing that the manufacturer will work to even further increase the resilience of the aircraft systems to AoA sensor failures so as to further enhance the safety of the aircraft. Boeing will also conduct a complementary Human Factor assessment of its crew alerting systems within the next 12 months, with the aim of potentially upgrading these to a more modern design approach."

Press room

AD full text, checklists, etc.
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Old 24th Nov 2020, 16:19
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Who would have thought in 1970, when Boeing was justly proud of their fine 747 and an air bus was a Vanguard, they
would have descended to this.
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Old 24th Nov 2020, 22:25
  #492 (permalink)  
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The hard part for Boeing is just starting as the company future is now riding on a uneventful return to service for the MAX. Another accident for almost any reason save the grossest pilot failure and the airplane, and probably the company, is done.
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Old 25th Nov 2020, 01:22
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Boeing 737 MAX Cleared By European Regulators NOVEMBER 24, 2020 BY BEN 36MISC.The Boeing 737 MAX has been grounded globally since March 2019, following two fatal crashes. For the past 20 months Boeing has been making fixes to the plane and working on getting it certified once again.

Last week the US Federal Aviation Administration (FAA) announced plans to “unground” the 737 MAX, and today European regulators have made a similar announcement.
In this post:
EASA signs off on Boeing 737 MAX Back in mid-October, Patrick Ky, Executive Director of the European Union Aviation Safety Agency (EASA), stated that he was satisfied with the changes that Boeing has made to the 737 MAX. However, up until this point the EASA hasn’t officially ungrounded the 737 MAX. That’s going to change.

The EASA has today published a Proposed Airworthiness Directive for the 737 MAX returning to service. With this, a 28-day public consultation period has started, with the final Airworthiness Directive expected to be published in mid-January 2021.

As the Executive Director of the EASA describes this development:
“EASA made clear from the outset that we would conduct our own objective and independent assessment of the 737 MAX, working closely with the FAA and Boeing, to make sure that there can be no repeat of these tragic accidents, which touched the lives of so many people.

I am confident that we have left no stone unturned in our assessment of the aircraft with its changed design approach. Each time when it may have appeared that problems were resolved, we dug deeper and asked even more questions. The result was a thorough and comprehensive review of how this plane flies and what it is like for a pilot to fly the MAX, giving us the assurance that it is now safe to fly.”

The 737 MAX could be flying in Europe in January 2021 EASA mandates 737 MAX changes The EASA’s Proposed Airworthiness Directive mandates several changes to the 737 MAX, including the following:
  • Software updates for the flight control computer, including the MCAS
  • Software updates to display an alert in case of disagreement between the two angle of attack sensors
  • Physical separation of wires routed from the cockpit to the stabilizer trim motor
  • Updates to flight manuals: operational limitations and improved procedures to equip pilots to understand and manage all relevant failure scenarios
  • Mandatory training for all 737 MAX pilots before they fly the plane again, and updates of the initial and recurrent training of pilots on the MAX
  • Tests of systems including the angle of attack sensor system
  • An operational readiness flight, without passengers, before commercial usage of each aircraft to ensure that all design changes have been correctly implemented and the aircraft successfully and safely brought out of its long period of storage
It’s interesting to note that even though the FAA and EASA worked fairly closely together and are going off the same information, the two organizations have mandated somewhat different changes.

Existing 737 MAXs will need software updates, and moreSupport from foreign regulators is significant The 737 MAX certification process and investigation has brought a lot of things to light, both regarding Boeing’s corporate culture, and also regarding its relationship with the FAA.

As the 737 MAX has undergone the certification process, one major question has been whether foreign regulators would follow the FAA’s lead.

It’s certainly a good sign for Boeing that approval is coming from both the FAA and EASA around the same time.

Ultimately it’s up to each individual aviation regulator to decide on their policy. Presumably they’re not all going to do test flights on the plane, so it’ll be interesting to see if there’s widespread support of FAA and EASA approval, or what ends up happening.

Will other regulators follow the lead of the FAA & EASA? We’ll see how passengers respond I’ll be very curious to see how the public responds to the 737 MAX returning to the skies:
  • So many people have said “I’ll never fly that plane,” but only time will tell if that’s just empty talk, or if people follow through on that; it could be like people who threaten to never fly an airline again, and then the next time when that airline is a dollar cheaper than the competitor, they book it
  • We’ve seen some airlines say they’ll let people rebook if they are scheduled to be on a 737 MAX, so I’m curious to see just how many airlines have a policy like this; perhaps it’s a moot point for now, as airlines are waiving change fees in general
  • Boeing is quietly rebranding the 737 MAX — for example, the Boeing 737 MAX 8 is now being branded as the 737-8, so clearly Boeing is hoping that people forget the “MAX” name
Would I be comfortable flying the 737 MAX when it returns to service? Well:
  • Have I lost a lot of respect for both Boeing and the FAA throughout this process? Absolutely
  • But personally I’d be happy to fly the 737 MAX again once it’s approved by multiple reputable regulators
Ironically airlines might be just as unhappy as passengers about the 737 MAX being cleared to fly again, because they’ll be on the hook for paying for these planes, and won’t be getting compensation from Boeing anymore.

Will passengers really not fly the 737 MAX? Bottom line The EASA has issued a Proposed Air Worthiness Directive for the 737 MAX, and it’s expected that the plane could be flying in Europe again by mid-January. The EASA does have some requirements for the plane, which aren’t identical to the FAA’s requirements, interestingly enough.

With both the FAA and EASA being onboard with the 737 MAX returning to the skies soon, we’ll have to wait and see what other regulators around the world do. I would imagine that most regulators in smaller countries with follow the lead of the FAA and EASA, but what about the Civil Aviation Administration of China, for example, especially given the political implications?

Do you think other regulators will follow the lead of the FAA and EASA?
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Old 25th Nov 2020, 08:24
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Not entirely true. When Boeing rolled out the 747, the 2 main European companies were flying the Concorde, the first airliner using fly-by-wire, which became one of the main Airbus features. One could say for the sake of the argument that the writing was on the wall in 1969 already. That said I agree that the fall of Boeing so deep has been a surprise to most of us .
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Old 25th Nov 2020, 13:53
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ATC Watcher: Not entirely true.

Your dates are a little confused;

B747: rollout 30 Sep1968, first flight 9 Feb 1969
Concorde: rollout 11 Dec 67, first flight 2 Mar 1969.

So the first Concorde flew after the rollout of the B747.

Concorde's fly by wire was all analogue, so bears little relation to the later Airbus digital FBW.
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Old 26th Nov 2020, 08:13
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Kenparry , thanks for the corrections, let's agree it was at the same time OK ? , my point was to say that Europe manufacturers were producing more than Vanguards in 1969 or 70 which is was what was mentioned . As to fly-by wire, Ivanoff, one of the Airbus engineers working on the A320 at the time always said that the FBW used was a derivative of the Concorde technology . That was also my point.

Back to the Thread subject :
I learned during the recent AW&ST webinar that there are 837 Max parked around the world that need to be modified and de-preserved. , it was said that on average it will take 300 hours per aircraft to put them back in the air. estimated at a 15-16 days process per airframe.
In addition the additional pilots training package is apparently 5h with 3h sim and 2 h CBT... So it will take a while to get every airframe back on line..
China has not yet agreed to lift the Grounding and can wait as they have overcapacity since they do not fly internationally at the moment..
As you say in your country : the Max is not completely out of the woods yet.
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Old 26th Nov 2020, 09:33
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And how many MAX simulators are available for training?
A high training volume required for the MAX in combination with very little training in general due to Covid.
It will take som work and money to untangle this mess.
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Old 27th Nov 2020, 12:13
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However, the first commercial flights of both types were almost exactly 6 years apart, as first 747 flight was Jan 22nd 1970, and first Concorde flights were not until Jan 21st 1976.
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Old 27th Nov 2020, 22:40
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In the UK Boeing have 3 at Gatwick and L3 have 1
The Boeing sims are going to be very busy. Not sure if the L3 one is approved or their instructors trained.
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Old 28th Nov 2020, 00:15
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In Canada AirCanada owns 2 and says it has access to a third one. Not sure about WestJet though.

you may find more at: Boeing, reversing itself, says all 737 MAX pilots will need costly flight simulator training | The Seattle Times
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