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

[DaveReidUK]

Originally Posted by Smythe

Interesting today how Boeing was careful to word the news of 777X blowing up on final ground test into a non-issue, and the stock soars...

It's perfectly possible that it will indeed turn out to have been a non-issue.

[Smythe]

It may, then why not be up front?

What are the results of the wing test?

I think the proposed solution is that both existing vanes will be used simultaneously rather than consecutively to provide a dual channel input to to the system which requires only a software change. Adding a third vane to existing aircraft is a whole different ball game and will delay things even further.

Even with three AoA inputs and polling software, there is no guarantee that MCAS would be sensor error free. Depending on where this extra vane is located, there are still certain situations such as uncoordinated flight, where all three vanes are outputting a different value to the FCC.

So following your logic, under common maneuvers such as a climbing turn, isnt one of the AoA shielded?

So with using 2 you are relying on the various algorithms applied to each to compare variables such as crosswinds, climbing/descending turns, vertical winds, and high AoA maneuvers to compare the 2 AoA readings, then another algorithm to report which one is valid?

[Speed of Sound]

Originally Posted by Smythe

So with using 2 you are relying on the various algorithms applied to each to compare variables such as crosswinds, climbing/descending turns, vertical winds, and high AoA maneuvers to compare the 2 AoA readings, then another algorithm to report which one is valid?

Absolutely.

Undoubtedly three sensors are better than two but because of location and the particularity of AoA measurement, it is not foolproof in the way that three temperature gauges measuring temperature at the same place would be.

Also more complex algorithms can introduce another failure point especially in a processor which it has been claimed is running close to capacity.

[kiwi grey]

Just the FAA

Originally Posted by fruitflyer

For airlines like Southwest an FAA clearance is all that's needed. Norwegian not so much.

Originally Posted by OldnGrounded

As a regulatory matter, FAA clearance is sufficient. But I think Southwest might have a difficult time explaining to pax why it is flying aircraft that other major CAAs are not willing to allow in their airspace. It doesn't take much imagination to visualize the headlines.

This is true, but only one of the issues. In an FAA-only scenario:

• Insurers are bound to be very reluctant to cover the aircraft & its contents
• US airlines (including SWA) couldn't fly a MAX to or from Mexico or Canada, or even to Alaska if that involved going through Canadian air-space

The absolute minimum would be to carry the Mexican and Canadian authorities along with the USA. IIRC, Transport Canada said that simulator training would be required, and the Mexican government owes the US Government a favour just now because ... ah, no, not so much.
Even if a MAX can be flown in the USA, Canada and Mexico, there still might be major insurance problems if EASA and CAAC hold off

[Speed of Sound]

Originally Posted by kiwi grey

Even if a MAX can be flown in the USA, Canada and Mexico, there still might be major insurance problems if EASA and CAAC hold off

I think that this may have more of an effect than regional restrictions, pilots’ union concerns, or public disquiet.

Many insurance underwriters will struggle to provide cover for an aircraft which a major international safety authority still has reservations about its fitness to fly. At the very least they will either massively increase premiums or restrict cover on the MAX.

Let’s not forget that many of the issues flagged by EASA were in addition to the initial concerns which grounded the MAX. A coordinated international ungrounding is the only realistic outcome here and the FAA and Boeing need to suck it up and accept that it could be the middle of 2020 before the 737 Max flies again.

[sphealey]

It is possible to talk oneself into being afraid of anything. It is very possible to talk oneself into distrusting any complex technological system, and gets easier the deeper one looks into the design, development, and testing of that system. The problem is, where does one stop? When is enough reanalysis and fixing enough? If the standard is, never, it must be perfect, be prepared to return to a world where you walk from your hut to your field and scratch the dirt with a stick. Until the blisters you get from using the stick break and get infected...

[fdr]

Originally Posted by Smythe

It may, then why not be up front?
So following your logic, under common maneuvers such as a climbing turn, isnt one of the AoA shielded?

?

Most aircraft are more or less in balance in a climbing turn, it keeps the lipstick off the windows at row 68Z and avoids sloshing elsan blue out into the aisles. There is a slight change in aoa between left and right as the aircraft rolls around the longitudinal axis... but no "shielding". Turns are a coordinated manoeuvre, due to design of the aircraft, yaw dampers, and driver skill.

[Big Pistons Forever]

While Boing clearly failed to adequately assess the implications of the MCAS system and likely allowed commercial pressures to override airworthiness rigour,, I am starting to feel that EASA is politicizing the return to service question. Where does legitimate concern cross over to Airbus protectionism .?

Maybe before EASA leadership make statements like “EASA” would not have allowed Boing to self certify MCAS they should review the EC225 crash report. It is s pretty devastating indictment of regulatory failure, especially a failure to learn the lessons of one fatal crash and only after the second fatal crash from the same cause, was the aircraft grounded.......that sounds depressingly familiar.......

post 1916 on the EC225 thread in the Helicopter forum offers a summary of some of the issues.

[Australopithecus]

Big Pistons, the delayed action of the FAA who had to be dragged kicking and screaming to the grounding by the other regulators set the stage for the conditions of the ungrounding. The FAA is perceived as having been captured by the industry generally and Boeing in particular, hence the reticence to accept any FAA certification process as untainted.

Will politics and national interest affect future type certs? Depends on which side of the money you stand. It does not help that trade, tariffs and treaties are all currently more in play than they historically have been.

I don’t personally think that EASA is the paragon of virtue in the airworthiness/documentation/procedures game, but at least they have not had their budgets slashed to the point where they have to accept wholesale self-certification with all of its attendant irony.

[EDLB]

Technical you need for such a powerful flight control system a DAL-A solution. If Boeing tries to cut corners again, we will not see the MAX in the air in 2020.

[pilotmike]

Originally Posted by Smythe

So following your logic, under common maneuvers such as a climbing turn, isnt one of the AoA shielded?

Seriously??? Care to explain how that works?

[Maninthebar]

We now know what the requirements for re-certification are from EASA, I am not aware of a similar structured presentation from the FAA. Perhaps they are similar.

If not, then we might reasonably enquire why the FAA are not making these requirements. After all, if you refer back to the beginning of this very thread you will find that the PPRuNe Hive Mind came up with the same issues identified in the Ky presentation.

[Torquelink]

I am starting to feel that EASA is politicizing the return to service question. Where does legitimate concern cross over to Airbus protectionism .?

I think this is more than a little unfair to EASA. Even assuming that the certification authority would stoop so low, they really don't need to - especially now of all times: Airbus is hardly in any need of protection.

[Speed of Sound]

Originally Posted by Big Pistons Forever

I am starting to feel that EASA is politicizing the return to service question.

In that case, can you point out which of EASA’s additional concerns do not need addressing?

[WHBM]

Originally Posted by Big Pistons Forever

I am starting to feel that EASA is politicizing the return to service question. Where does legitimate concern cross over to Airbus protectionism .?

That's just a nonsense; claiming that EASA's professional concerns are done out of "being political" is the sort of Boeing management attitude that got us here in the first place. The Max has very many European parts on it of course, starting with its engines which are 50% a French product between Safran and GE. Safran (bit of a clue in the last four letters of the name), which still has a significant French government ownership stake, must be going to lose a lot of money in all this.

[Maninthebar]

Originally Posted by WHBM

That's just a nonsense; claiming that EASA's professional concerns are done out of "being political" is the sort of Boeing management attitude that got us here in the first place. The Max has very many European parts on it of course, starting with its engines which are 50% a French product between Safran and GE. Safran (bit of a clue in the last four letters of the name), which still has a significant French government ownership stake, must be going to lose a lot of money in all this.

.....and it's not only SWA who are suffering for the lack of MAX deliveries

[SLF3]

EASA will be treading on eggshells - the last thing they want is a tit for tat certification war with the US, particularly given the mercurial temperament of the current US president and his willingness to ban this and tariff that.

I don't think EASA are politicising it: I think (after ten months, with no end in sight) it is so bad that they cannot ignore it.

[.Scott]

Originally Posted by Loose rivets

I know it's too late now, but just why is the H-stabilizer not hinged at the front?

I don't know whether hinging the stabilizer is workable, but I would not say that it is "too late now".
I don't think that the FAA is going to allow practicality or economics to factor into its go/no-go decision.

So far, I have not heard anything in the news that would suggest that changes to the air frame can or cannot be avoided.
I am not predicting that such changes will be needed, but they are not off the table.

[Ian W]

Originally Posted by Fly Aiprt

Thanks for that, grizzled.
I would add that the decisions of Boeing and the FAA dearly impacted hundreds of innocent families whose only fault was to trust the planemaker and regulators.
What did they do for those families after the crashes ? Incriminate the pilots, and move their cases to Indonesia in order to compensate less.

They would keep their own families "out of this", but the flying public is invited to put their own families on board...
I for one wouldn't board any of those 737 MAX unless I have witnessed Boeing and the FAA's top brass flying around the world with their best beloved...

I think that the same could be said for training of the crews. As was shown the first Lion Air aircraft flew to destination after the crew switched of Stab Trim and the Second Lion Air flight, had the captain remained flying could well have recovered. There have been multiple posts here that the aircraft were flyable and could have been recovered but the crews lacked the training to do so. I think I echo a previous poster in saying that there needs to be more attention to training of manual flying and also handling of 'surprise' failures especially those failures that provide cascades of 'attention getting' alerts. (and human factors people need to pay attention to potential cognitive overloads caused by such cascades of alerts)

Do you want your family to fly on an aircraft with a crew that has not been trained sufficiently to be completely confident in switching off automatics and flying and recovering the aircraft manually?

[Fly Aiprt]

Originally Posted by Ian W

Do you want your family to fly on an aircraft with a crew that has not been trained sufficiently to be completely confident in switching off automatics and flying and recovering the aircraft manually?

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...