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-   -   MAX’s Return Delayed by FAA Reevaluation of 737 Safety Procedures (https://www.pprune.org/rumours-news/621879-max-s-return-delayed-faa-reevaluation-737-safety-procedures.html)

DType 6th Sep 2019 15:06

SoS
The date of the communication may be meaningful?

Speed of Sound 6th Sep 2019 15:41


Originally Posted by DType (Post 10563475)
SoS
The date of the communication may be meaningful?

Doh!

I thought it was very ‘undiplomatic’ although it was marked private.

OldnGrounded 6th Sep 2019 15:55


Originally Posted by Speed of Sound (Post 10563435)
Wow!

No delegation to FAA” That is harsh!

Or maybe just careful.

fgrieu 6th Sep 2019 16:14

From a presentation of 2019-09-03 by EASA's Executive Director Patrick KY, as posted on the European Parliament's website:
IMHO, "Too high forces needed to move the manual trim wheel in case of a stabiliser runaway" is technically challenging. I can't see an easy fix. At best, software can make stabilizer runaway extremely unlikely. Training can improve recovery to a degree (see the Boeing advice on "aerodynamically relieving airloads" using manual stabilizer trim thread), but subject to altitude constraints.

PEI_3721 6th Sep 2019 16:40

# 2225
The fourth item could also be challenging;
It can be assumed that MCAS is now well protected from a single AoA failure, but the coincident effects on other systems - ADC, speed corrections, Stick Shake, EFIS low speed awareness, are unacceptable during takeoff given the likely failure rate of the AoA input (accident history / investigation).

Why did the AoA fail at or before takeoff in the two accidents and not later in the flights?

A failure in a dual AoA system can be detected by comparison, and the disagreement alerted, but a correct value cannot be identified, which other systems could switch to. Hence rumoured requirement for a triple AoA system - or a much higher reliability sensor.

Similarly for flight without MCAS, which could be acceptable for rare occurrences, but if the AoA reliability was low then this too could be unacceptable for certification.


oceancrosser 6th Sep 2019 16:45

Thanks fgrieu... one can't begin to wonder if the MAX return to service is going to happen before Summer 2020...

Another interesting thing in that EASA document is where they propose ECO-Labels on aircraft, like on your household appliances, washers and dryers...

ST Dog 6th Sep 2019 17:53


Originally Posted by CurtainTwitcher (Post 10562995)
It really was that simple. This whole crisis was to increase profit by $1 million per airframe in reduced training costs, for some large operators.

$280 million is a sizable chunk of change.

And of course you try to build what the customer wants. I read elsewhere that SWA wasn't really interested if it was going to take significant retraining/resources (may as well buy a different aircraft then). So if your primary customer wants something you try mighty hard to give it to them. At the same time SWA said sure we'll buy them under that scenario, but for us to commit we need some assurance you won't change the goal later, hence the $1 million incentive.

Sometimes you win such a gamble, sometimes not. Here, in the end, Boeing did not. Neither did SWA.

edmundronald 6th Sep 2019 21:03


Originally Posted by Speed of Sound (Post 10563435)


Wow!

No delegation to FAA” That is harsh! The FAA must be feeling like Boris Johnson after his brother resigned, to put the national interest above friendship with his brother.

I can only assume that this stance has been taken after EASA failed to reach a unified approach to the recertification. Something tells me that Boeing and the FAA are going to have to compromise on the sim time requirements at the very least.That will pose some contractual difficulties for Boeing as I assume that the ‘iPad only’ conversion was written into the purchasing agreements.

And condition #2 is so open ended as to be meaningless.

And we haven’t yet seen what the Chinese will demand.

Edmund

Chris2303 6th Sep 2019 21:14


Originally Posted by Speed of Sound (Post 10563435)
No delegation to FAA” That is harsh!

I don't think that anyone in Boeing or the FAA understands the damage done to both their reputations by self certification.

The actions of EASA (in particular) may just be a reminder to the USA that the FAA is not the sole certifying agency. One wonders when Canada and China are going to follow suit

Less Hair 6th Sep 2019 21:29

I understand why EASA is now so strict, they have to be this way. But separating authorities and certification again is the wrong way to go.
We need a bullet proof trustworthy system again. Where everybody can rely on each other. Better bring back the trust again and change everything that's in between.
EASA is not fighting Boeing or anybody else but they must be sure that no interference with the industry takes place (again). We need a united approach to bring it back to flight not a patchwork world. A robust, proven and flight demonstrated modification will be the beginning.

Speed of Sound 6th Sep 2019 21:59


Originally Posted by Less Hair (Post 10563711)

We need a bullet proof trustworthy system again. Where everybody can rely on each other. Better bring back the trust again and change everything that's in between.

And the first step must be an end to the FAA’s Designated Representative system.

Teachers don’t get the kids to mark their own homework. The same should apply here. :suspect:

Bend alot 6th Sep 2019 23:22

3. Accidents of JT610 and ET302 are deemed sufficiently understood.

I am guessing EASA want the final reports out to review, before they guess what needs to be addressed. They would not want to commit only to get embarrassed by an oversight, by something in one of the two reports yet to be released.

etudiant 7th Sep 2019 00:52

Seems the 777X also has some issues.
Seattle radio KOMO reports the aircraft had a door pop off during extreme pressurization testing, with FAA officials watching.
https://twitter.com/hashtag/KOMONews?src=hashtag_click

Perhaps merely something misrigged, but Boeing historically uses plug type doors, so perhaps something more serious.

Dave Therhino 7th Sep 2019 01:49

Further reporting on KOMO now that the final test where they bend the wing to failure failed.

https://komonews.com/news/local/door...ng-stress-test

Pilot DAR 7th Sep 2019 02:34


And the first step must be an end to the FAA’s Designated Representative system.
Might not serve the public interest as well as could appear at first glance. Delegates relieve the authority of having to employ thousands more staff to have the full breath of knowledge and experience, as well as capacity for the workload. By applying the logic that the FAA should not delegate design approval there would seem to be a parallel suggestion that all pilot examiners, and maintenance signatories should also be employees of the FAA. after all, they too issue or renew certificates on behalf of the authority. I'm not saying that the designee system worked perfectly in this case, but unless you want every STC, C of A and pilot license or rating to be issued by an employee of the authority, paying all those staff, and waiting for the service. it is probably better to refine and perhaps oversee the present system more carefully.

Possibly, aircraft were issued a design approval with a flaw, by a designee, and unfortunate crashes can be attributed to that. Has a pilot, who has been issued a license by a designated examiner, ever caused an accident? Has there been a call to return all pilot examinations to staff of the authority?

Dave Therhino 7th Sep 2019 02:50

The DER system worked very well for over 50 years. Don't associate that system with the recent direct results of ODA.

MemberBerry 7th Sep 2019 05:27

It's interesting that the EASA presentation included a graphical description of MCAS by AFP, calling it an "anti-stall system":

https://cimg5.ibsrv.net/gimg/pprune....565aee6f18.png

Bend alot 7th Sep 2019 05:47


Originally Posted by MemberBerry (Post 10563874)
It's interesting that the EASA presentation included a graphical description of MCAS by AFP, calling it an "anti-stall system":

https://cimg5.ibsrv.net/gimg/pprune....565aee6f18.png

Mandatory wearing of helmets on a push bike is

a) a injury prevention method.
b) a death prevention method
c) a regulatory requirement.



D) ALL of the above!!!!!!!!!!!!


MCAS is only a regulatory requirement - none of the others were required when MCAS was developed and redeveloped.

Stick to the story - stalls never happen at high AoA and never would a lighter stick force, at a high AoA lead to even one unintentional stall - ever.

ozaub 7th Sep 2019 05:55

EASA need not wait for both accident reports but will I imagine wait for Indonesian report on JT 610. It’s due next month.
ICAO Annex 13 requires that State conducting investigation make Final Report publicly available “if possible” within twelve months. If not, State shall make an interim statement on each anniversary of the occurrence, detailing progress and any safety issues identified.
I expect the report to be just as timely, professional and non-judgemental as Indonesia’s report on Air Asia A320 flight QZ8501 - https://www.bea.aero/uploads/tx_elyd...XC-reduite.pdf. Indeed some aspects will be depressingly similar; defect reporting, maintenance, startle/CRM.

groundbum 7th Sep 2019 09:01

A very unfortunate side effect of this debacle is that Boeing have put themselves into play in world trade tensions. Whereas before the different FAAs all had mutual recognition agreements, at a time of Trump inspired trade wars Boeing has made themselves into the ball that will be kicked up and down the muddy pitch until it is bent out of all shape. And all to save a few hundred million dollars and undo decades of superb engineering. It's hard to think of a bigger self-inflicted injury. The entire 737 management team at B would resign out of honour if they were Japanese.

G


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