Source: Boeing whistleblowers report 737 Max problems to FAA

[nitpicker]

https://www.cnn.com/2019/04/26/politics/faa-hotline-reports/index.html

Source: Boeing whistleblowers report 737 Max problems to FAA

By Drew Griffin, CNN Investigations

Updated 1:15 AM ET, Sat April 27, 2019

(CNN) — The day after Ethiopia's minister of transportation released a preliminary crash report on Ethiopian Airlines flight 302, four Boeing employees called an Federal Aviation Administration whistleblower hotline that allows employees and the public to report aviation safety issues.

A source familiar with the matter says the hotline submissions involve current and former Boeing employees describing issues related to the angle of attack sensor -- a vane that measures the plane's angle in the air -- and the anti-stall system called MCAS, which is unique to Boeing's newest plane.
(snip)

The FAA tells CNN it received the four hotline submissions on April 5, and it may be opening up an entirely new investigative angle into what went wrong in the crashes of two Boeing 737 Max commercial airliners -- Lion Air flight 620 in October and Ethiopian Air flight 302 in March. Among the complaints is a previously unreported issue involving damage to the wiring of the angle of attack sensor by a foreign object, according to the source.

Boeing has reportedly had previous issues with foreign object debris in its manufacturing process; The New York Times reported metal shavings were found near wiring of Boeing 787 Dreamliner planes, and the Air Force stopped deliveries of the Boeing KC-46 tanker after foreign object debris was found in some of the planes coming off the production line.

Other reports by the whistleblowers involve concerns about the MCAS control cut-out switches, which disengage the MCAS software, according to the source.

A preliminary report by Ethiopian investigators found that a malfunctioning angle of attack sensor on Ethiopian Airlines flight 302 was sending incorrect data to the MCAS system. The MCAS, behaving as if it were in a stall, repeatedly forced the nose of the plane down as the pilots struggled for control, and ultimately the aircraft crashed.
(snip)

The airline's CEO will hold a news conference on Monday following a shareholder meeting in Chicago. A meeting of international civil aviation authorities is also taking place Monday in the Dallas area to discuss the issues surrounding the 737 Max.

[Sherman A1]

1. These aircraft and I use that term loosely

Need to be scrapped.

[watoos]

2. I don't think a software upgrade will cure the problem.

Or giving the pilots a class, not on a simulator, teaching them how to react, makes me feel any better.

[Roy Rolling]

3. Beyond a technical fix

This is a gigantic PR problem for Boeing, partially made worse by our idiot president publicly reassuring flyers the plane was safe. When there was a critical flaw in the jet making it crash, our idiot president was on TV telling people "have confidence", go ahead and fly on his buddy's 787s.

Fucking moron. A jet is fatally flawed, he's encouraging people to get on board. Who does that except in the Biblical version of "the Devil" himself? Who gives a green-light to a death machine?

And because of getting in bed with "the Devil", Boeing will never be able to save that plane. No technical fix can restore the lost confidence of lied-to flyers. Ever. It's toast. Corporations like Boeing should be smarter than to have the Village Idiot endorse their company.

[Vinca]

4. I cringe to think who might be in charge of the FAA. Didn't Trump want his pilot to head it?

[GetRidOfThem]

5. I noticed an i,important detail in this story...

That they had trouble with the cut out mechanism. The Ethiopian Airlines pilots did exactly what the were supposed to do: they tried to switch the system off.

So it seems we have had two failures: the sensor vane and the system cut-out.

[Ramsey Barner]

6. Hats off to the whistleblowers.

Once again.

[watoos]

7. I mean, it doesn't make me feel any better,

listening to an explanation that metal shavings cut a wire to a sensor. WTF, in 2 plane crashes, metal shavings are to blame? That has to be the lamest explanation yet. Why would the wires be exposed to being pinched?

[localroger]

8. The problem is not fundamental to the plane

The problem is that Boeing wanted to sneak the MAX in under the existing 737 certification, and installation of a new and untested system like MCAS, which was necessary because of the new engine position, jeopardized that.

MCAS should have gone through a thorough review process which would have revealed its single points of failure. Instead it was snuck in and glossed over.

That the airframe is less stable with the new engine position is not really a problem. No aircraft is completely stable, and part of the pilot's training is learning what it takes to keep it stable. The MAX wouldn't really even need MCAS if Boeing simply admitted that it was a different aircraft than the 737 and needed additional pilot training; the purpose of MCAS was to make the MAX "feel" like the old 737 to the pilots. The problem with that is that when MCAS failed, the pilots either had no idea what to do, or in the case of the Lion Air flight the cutout mechanism may have failed when the pilots correctly tried to use it. Again, single points of failure like that aren't supposed to exist, and a proper design review would have caught that.

Instability isn't an inherently bad thing; it's necessary for controlled flight, which is one of the major things the Wright Brothers learned. Before them people were trying to build stable aircraft. Coming from their bicycle shop the Wrights recognized that the plane had to be maneuverable, and it would be up to the pilot to keep it stable. And experience shows pilots can do that really well if their controls are correctly designed.

[Locrian]

9. yes

the MCAS is more of a cover-up band aide

Additional simulator training would have cost more - but actually addresses the issue

[watoos]

10. So what did the pilots do wrong in the Lion Air flight?

[localroger]

11. It's not clear

It's not definite so far whether they didn't know how to turn MCAS off, or whether the cutout didn't work when they correctly activated it. Either way putting MCAS through the usual review process for new aircraft features would have probably fixed the problem.

[Locrian]

12. not enough information

They're all complex systems (aircraft) but from where I sit - they made a complex machine more complex and didn't communicate well the additional complexity, nor did the "added on" system have critical features to check itself (compare sensors /channels, verify angle on ground etc).

I keep hearing "but the US pilots know now to disengage the system, it's easy etc" - but it's still a system (human user interface) failure if they do not communicate that process to the pilots adequately.

They thought that complexity could be mitigated by the sensor /software - not fully hidden but not clearly communicated.

If the MCAS didn't disengage when ordered - that's a whole different problem...

[Boomer]

13. Thank you

That was one of the most insightful explanations of this situation that I've read.