JohnBurke

Maybe it's rogue TSA out there again, trying to look in cockpits.

Not satisfied with breaking them domestically, they've got international.

rickair7777

This sheds some light on why Boeing sold the AoA Disagree indicator as an option, vice standard equipment. Not really good...

https://www.npr.org/2019/05/06/72055...h-in-indonesia

Mesabah

I love how Boeing points out specifically that senior leadership didn't know of the issue. As an engineer, I would walk away from that company immediately. There are criminal charges here for covering up required AD reporting, and senior execs want to pin it on their employees.

JohnBurke

It's a non-issue. The Ethiopian crew verbalized the AoA and correctly identified the problem, and even followed the procedure up through cutting off stab trim; we all know this.

The crew had a flyable airplane and the only reason the aircraft crashed was the crew actions. All the chirping about AoA issues and MCAS is a red herring, and politics.

The procedure wasn't any different for these malfunctions than a runaway trim, and there has never been a reason or practice that required increasing airspeed beyond Vmo/Mmo after a trim problem, let alone reactivating stab trim after using the cutoff switches. This was all crew.

pangolin

I argue training. They could not physically manually move the trim. They turned it back on to get it to move. Had they trimmed then immediately turned it back off it might have worked. You know they were overloaded.

2StgTurbine

There seem to be 2 camps.

1. The airplane is broken and shouldn't not have been certificated.

2. The plane has flaws, but a well trained crew should be able to overcome those flaws.

The problem with camp 2 is the solution to the problem comes down to "be a better pilot." The history of aviation has showed us that mindset does not get the best results.

The crew DID the correct procedure, but it didn't get the results they wanted so they acted outside of the SOP. Sure, they failed to control their airspeed which made the situation worse, but is that the whole story?

Manual trim is slow and as the speed increases, the nose down force increases. Is there a speed/altitude combination that makes the recovery impossible without electric trim? Is that speed/altitude combination outside of what a normal crew may experience? I can imagine it can be scary to feel the aircraft pitch over watching the ground get closer and the only thing you can do is use slow manual trim. Maybe their training didn't prepare them for this.

To me this is like the early days of microbursts. This is a new threat that only a few have experienced. It took a while to come up with good windshear recovery procedures. The industry standard procedure isn't even "the best." If you knew what area of the microburst you were in, you could optimize your recovery. But humans are not good at correctly analyzing rapidly changing conditions with conflicting information. As a result, the "dumbed" down the procedure by having us not touch the flaps or gear.

Maybe the MCAS issue is the same. SOPs need to be updated to the way pilots actually perform and training needs to be adjusted to simulate the worst case scenario.

Even go-arounds are routinely screwed up, so I can understand how a crew could incorrectly handle a plane with unreliable airspeed, a flight control issue, and an SOP not immediately fixing the problem close the ground even the they DID correctly identify the problem.

Xjrstreetcar

Do you think they would have balled it up if the failure had occured on any other 737 variant....

Adlerdriver

^^^^^Here's an example of selective interpretation.^^^^^^
Throwing the cut-out switches may technically meet the initial criterion of "correct procedure" but there's a bit more to it than that. Ignoring airspeed to the point that it exceeds flight envelope limits rapidly negates any procedural compliance that may have previously been fulfilled.

Yes - lack of airspeed control is the whole story. They didn't get the results they wanted because it was impossible to get those results with the airspeed outside the far right limits of the envelope.

2StgTurbine

That is why it is better to wait for the full report. What airspeed were they at when it started to nose over? What airspeed were they at when they identified the problem? Did MCAS cause the nose to drop to a point where even if the thrust was brought to idle the airspeed could not be arrested in time? What is the reaction time needed before aircraft control becomes so challenging that it causes 2 pilots to forget about thrust?

While I agree that the crew made a mistake in not bringing back the power, I have not seen enough evidence to believe that alone would have prevented this.

JohnBurke

Do you know why they couldn't move the trim?

Because they were accelerating continuously. Step one is fly the airplane.

They knew the procedure. They simply did not do what they were supposed to do.

Have you actually read the report? It's very clear.

https://assets.documentcloud.org/doc...X-Ethiopia.pdf