MAX’s Return Delayed by FAA Reevaluation of 737 Safety Procedures

[Peter H]

Originally Posted by Loose rivets

I know it's too late now, but just why is the H-stabilizer not hinged at the front?
It would take a long lever arm to reach the jack-screw, but it is doable within existing confines.

Somebody brought up a query from post #3. This topic was explored in a Tech Log thread. THS hinge point

I gained the impression that it would be difficult to move the pivot point from its current position close to mid-section.

[Speed of Sound]

The FAA will eventually come to an accommodation with other authorities, and I can’t help thinking that sim training will be part of the final agreement, especially as accident reports will soon be released that will make it absolutely clear how under the cosh both crews were.

If Boeing had to chose between further training for MAX crews or retro fitting servos to the stab trim systems of 7000+ NGs I suspect that they would jump at the extra training.

[Fly Aiprt]

Originally Posted by Speed of Sound

The FAA will eventually come to an accommodation with other authorities, and I can’t help thinking that sim training will be part of the final agreement,

Don't know for the FAA, but EASA boss Patrick Ky made it absolutely clear that the training requirements in Europe will be EASA's decision (end of Q&A on the video).

[Ian W]

Originally Posted by Fly Aiprt

The answer is obvious, Ian W : Boeing and FAA top brass should go flying on a random third world airliner, with a crew chosen at the last moment, and having just performed whatever training Boeing and the FAA deemed necessary.
If it's 3/4 of an hour on a tablet, so be it.
Maybe they'll suddenly realize that a little bit more might not be a bad idea...

From some of the posts in this thread they would not need to travel that far. Reduced training was one of the demands from the customers too. It is a kind of institutional normalization of deviance.


From another thread - this applies absolutely to the Max. See 1.2 of link
UK CAA LOC due failure to keep aircraft trimmed

[Speed of Sound]

Originally Posted by Fly Aiprt

training requirements in Europe will be EASA's decision (end of Q&A on the video).

It will be a joint decision by all aviation authorities.

Anything else would be madness.

[Fly Aiprt]

Originally Posted by Ian W

Reduced training was one of the demands from the customers too. It is a kind of institutional normalization of deviance.

So now it's not Boeing's but the customers' fault...

[Fly Aiprt]

Originally Posted by Speed of Sound

It will be a joint decision by all aviation authorities.

Anything else would be madness.

The FAA seems to have demonstrated some form of madness...
This reluctance to ground the airplane, for instance...

[Magnis]

More concerns for Boeing.
Boeing CEO expects 737 MAX to resume flying around November, but possibly not in all countries

By Dominic Gates
Seattle Times aerospace reporter

Boeing chairman and chief executive Dennis Muilenburg on Wednesday reiterated his projection that, despite concerns publicly expressed by Europe’s air safety regulator, the 737 MAX should begin to return to service around November.

However, he conceded that lack of alignment among international regulatory bodies could mean that the grounded jet may first resume flying in the United States, with other major countries following later.

www seattletimes com/business/boeing-aerospace/boeing-ceo-expects-737-max-to-resume-flying-around-november-but-possibly-not-in-all-countries/

[OldnGrounded]

Originally Posted by Speed of Sound

It will be a joint decision by all aviation authorities.

Anything else would be madness.

If that's the case, it seems likely that the resolution will take rather a longer time than Boeing and the FAA have publicly suggested. It doesn't appear that EASA intends to be hurried.

[sb_sfo]

Let alone China given the current political climate?

[Tomaski]

Originally Posted by MemberBerry

Actually that's probably what happened to the Lion Air accident flight, not to the Ethiopian flight. There was not much trimming done on the Ethiopian flight, but on the Lion Air accident flight they did a lot of trimming while fighting MCAS. And the control column forces recorded by the DFDR seem to indicate that the Lion Air captain handed over control to the FO shortly before they lost control.

In addition to the change in pilot electric trim inputs (from frequent to infrequent), the DFDR traces also appear to show a brief, but marked divergence in the control forces exerted between the left and right side control columns. Normally there is a small variance with the pilot flying side showing more force than the non-flying pilot (which is how we can intuit when the change in control took place). At first there was a question raised whether this could have been a mechanical issue, but since that issue has not come forth in any of the Boeing/FAA/EASA discussions, then it is suggestive of inadvertent control interference. We have evidence that the Captain handed control to the FO in order to refer to a manual. It was suggested by another poster awhile back that if the Captain was reaching for his manual (usually stored in a pubs bag to the left and behind), his right leg may have drifted in front of the control column and thus interfered with an aggressive pull by the FO when MCAS activated. Throw in the sudden shock of the Captain being kneecapped into the mix (Captain shouts, FO releases back pressure, nose drops, etc), it may have contributed to the ultimate loss of control. Unfortunately, we don't have a full CVR transcript that might illuminate what exactly transpired.

[armchairpilot94116]

It may be necessary for a whole new management team at Boeing.

[WHBM]

Originally Posted by Magnis

Boeing chairman and chief executive Dennis Muilenburg on Wednesday reiterated his projection that, despite concerns publicly expressed by Europe’s air safety regulator, the 737 MAX should begin to return to service around November.

However, he conceded that lack of alignment among international regulatory bodies could mean that the grounded jet may first resume flying in the United States, with other major countries following later.

Has Muilenburg stopped talking to EASA ?

In fact, did he ever start ?

[MemberBerry]

From those slides presented to the European Parliament, EASA said they found 4 significant technical problems that would need to be addressed:

- Lack of exhaustive monitoring of the system failures resulting in a stabiliser runaway
- Too high forces needed to move the manual trim wheel in case of a stabiliser runaway
- Too late disconnection of autopilot near stall speed (in specific conditions)
- Too high crew workload and risk of crew confusion in some failure cases, especially Angle of Attack single failure at take-off

And, according to the same slides, the solutions Boeing has been working on are:

- Extensive change to the Flight Control Computer architecture and logics (incl. Autopilot)
- Improved crew procedures (and associated training)
- Improved architecture and/or logics for the Angle of Attack system

It seems none of those directly address the issue with the high force that may be required to move the manual trim wheel. I wonder what Boeing's plan is regarding that. I'm guessing they will just try to convince the EASA that it is not actually an issue. But, if after the flight tests the EASA is still not convinced, things could get very messy.

[JPJP]

Originally Posted by MemberBerry

It seems none of those directly address the issue with the high force that may be required to move the manual trim wheel. I wonder what Boeing's plan is regarding that. I'm guessing they will just try to convince the EASA that it is not actually an issue. But, if after the flight tests the EASA is still not convinced, things could get very messy.

One of the interesting off-shoots is the discovery that none of the NG or MAX simulators provide realistic forces on the manual trim wheel.

Surprise !

The Sims are being updated.

[Speed of Sound]

Originally Posted by WHBM

Has Muilenburg stopped talking to EASA ?

In fact, did he ever start ?

Unfortunately I suspect that senior management at Boeing see the FAA as a sub-contractor charged with sorting out their regulatory problems for them. Even worse, I’m sure there are people at the FAA who see themselves in that role too!

[Maninthebar]

Originally Posted by MemberBerry

From those slides presented to the European Parliament, EASA said they found 4 significant technical problems that would need to be addressed:



And, according to the same slides, the solutions Boeing has been working on are:



It seems none of those directly address the issue with the high force that may be required to move the manual trim wheel. I wonder what Boeing's plan is regarding that. I'm guessing they will just try to convince the EASA that it is not actually an issue. But, if after the flight tests the EASA is still not convinced, things could get very messy.

For as long as manual trim is referenced as a risk management tool in memory items, QRH, checklists, manuals or ADs then it will need to be useable by flight crew.

Either it is necessary or it is not

[MemberBerry]

Originally Posted by Maninthebar

For as long as manual trim is referenced as a risk management tool in memory items, QRH, checklists, manuals or ADs then it will need to be useable by flight crew.

Either it is necessary or it is not

Maybe they plan to address it indirectly through the "Improved crew procedures (and associated training)" part of the proposed solutions. For example by re-including the "roller-coaster" technique in the training materials. Of course that wouldn't be ideal, since you need to have enough altitude to use that technique.

Any solution involving hardware changes to the stabilizer trim system would open the "What about the NG?" can of worms, and I'm guessing Boeing would prefer to avoid that.

[krismiler]

The MAX wasn’t simultaneously grounded by the worlds aviation authorities and a return to the skies is unlikely to occur at exactly the same time either. If and when agreement is reached, the first flights will almost certainly be in the US which has the most aircraft on the ground and the best means of getting them back in the air.

Other countries would follow suit suit in their own time with China being the last one as a display of independence and a response to US trade tariffs.

[Australopithecus]

Originally Posted by Peter H

Somebody brought up a query from post #3. This topic was explored in a Tech Log thread. THS hinge point

I gained the impression that it would be difficult to move the pivot point from its current position close to mid-section.

What would moving the axis do? And more importantly, imagine the grotesque manual trimming forces that would be required to move a stabiliser that was so mounted.