What was improper about the execution of runaway trim by either LNI610 or ET302? Those two cases are different. LNI043 and LNI610 are also different but the similarity is 4 of 5 pilots didn't recognize it as runaway trim. And does it? Boeing says it does, but saying things doesn't make it true. It's much more aggressive than the kind of runaway trim pilots are trained for.
So again, what was improper? Especially ET302 where they absolutely did run the checklist rather immediately and by that time it was already in a mistrim situation.
ET302 ultimately turned the electric trim back on which was their death knell, in violation of procedures.
A contributing factor to ET302 is that mechanical trim wheel rotation can be very difficult in some flight regimes.
A further contributing factor is ET302 left an unreasonable amount of power in and got to an overspeed situation, which makes rotating the trim wheel yet more difficult. Being trimmed a bit nose down should not kill you. It should be the kind of thing you experience in training.
> It's much more aggressive than the kind of runaway trim pilots are trained for.
Bullshit. A stuck stabilizer trim switch will run away much faster than MCAS, and this is the primary thing they're trained for. The problem with MCAS is that it's an insidious, intermittent runaway-- an unlikely failure mode for a switch.
But sure, add to my list that "the trim wheel is often very hard to rotate manually", and "the flight crew left the thrust levers nearly full-forward creating an overspeed condition".
>ET302 ultimately turned the electric trim back on which was their death knell, in violation of procedures.
No it wasn't, they'd run out of checklist, and were deep in "oh shit" territory.
>A contributing factor to ET302 is that mechanical trim wheel rotation can be very difficult in some flight regimes.
>A further contributing factor is ET302 left an unreasonable amount of power in and got to an overspeed situation, which makes rotating the trim wheel yet more difficult. Being trimmed a bit nose down should not kill you. It should be the kind of thing you experience in training.
It was absolutely not unreasonable given the environment and stage of the flight (initial climbout) and the fact that pulling power would have led to nose drop (the opposite of what the current desired tendency of the plane was). Also, the plane was suffering by definition airspeed unreliable which dictates advancing throttles to the appropriate throttle position for the desired state of flight and leaving them there.
And what training? Oh! You mean that training they should have had because MCAS was a two sensor system, and therefore required level D simulator time that never happened because the manufacturer decided to cut corners to make more sales of their "best selling plane of all time"? That training?
Or the one hour glorified PowerPoint training that never mentioned a single detail of a flight control computer algorithm, or the disabling of a trim override switch built into the yoke, or the changing of the functionality of the STAB TRIM CUTOUT switches on the console to degrade the granularity of control with regards to which systems were electrically isolated from the trim motors because a hidden AoA dependent control routine had to be allowed to run uninterrupted because to do so would jeopardize their competitive advantage/ability to generate shareholder value by disqualifying their airframe outright or severely delaying its delivery because regulators started asking really inconvenient questions? That training?
The training unacceptable because Boeing would owe USD 1,000,000 per airframe to one of their largest customers if they implemented their safety system correctly in accordance to engineering best practices? That training?
The training that would have to happen anyway after their hacked together design had already killed 400 people, increasing scrutiny, causing them to finally do analysis they should have done in the first place, but didn't, because they were too busy trying to financially engineer the company after absorbing the management that drove McDonnell Douglas into the ground?
I get it. You sound like a knowledgeable dude, but you also sound like someone who has absolutely not sat front and center, day in, and day out, as companies try to go through the wildest mental gymnastics to avoid being held responsible for complying with regulations that have a damn good reason for being there.
You know what? Those pilots might have made mistakes. But the entire job of an Engineering firm is to ensure that the opportunity for those mistakes to occur are as rare and infrequent as practicable, with a dash of practicality thrown in; at least enough to keep the bean counters and management from sweating bullets. That means clearly communicating details of safety critical systems, being willing to admit a system is safety critical, and putting your bloody books behind in priority to getting the job done right as much as is reasonably necessary.
I'm a hobbyist. I do Quality Assurance as my day job. I could see plain as day the issues and risks they would be taking. I sat down and calculated the bloody forces that would have to be applied to the screw jack to actuate against the airstream at those velocities, and the torque numbers I got without even factoring in the extra pressure from the elevators was well into the output range of an automotive engine. I could also tell, just from the press releases over the development years the type of culture they had slipped into. That complacency by management kills, and did kill people.
Those pilots were the very last thing between those people and that crater, and did everything to the letter to the moment they had to improvise, and even then, they went into it insufficiently informed on the particulars of their aircraft.
I've bounced the details of this entire event passed maintenance people, passed crash investigators, passed anyone who'll care to listen. Boeing did things that are pretty much universally amongst them considered "things no one in their right mind should do."
If you want to buy in to "oh, they just sucked as pilots", fine. I'll give you Lion Air, but Ethiopian Airlines has a stellar safety record, and can fly in American airspace. So they obviously can't be that bad.
Oh, almost forgot!
>Bullshit. A stuck stabilizer trim switch will run away much faster than MCAS, and this is the primary thing they're trained for. The problem with MCAS is that it's an insidious, intermittent runaway-- an unlikely failure mode for a switch.
I call Bullshit right back, sir, seeing as, just as you mentioned, MCAS manifests differently from the classical stab trim runaway. Something which could be cause for pause for someone expecting a continuous runaway.
Just because they weren't you now does not mean primary fault can or should be attributed to them.
They walked onto that plane, cocksure, and as full of enthusiasm as you would have on any day. Up until the point Boeing's reckless design decisions came to light, no one had a clue just how different the MAX was from the 737's every airline pilot is familiar with.
You want to trade places with them? Ask God. He may oblige. Then mayhaps 150 or so may still be alive. That doesn't change the fact Boeing created an unsafe plane, hid the fact/didn't analyze hard enough to determine that fact at the pressuring of management, and to add insult to injury, tried to firmly pin the blame on the pilots, your comrades. It isn't even the first time they've done it if you recall the nastiness of the rudder reversals in the 90's, and some of their difficulties getting the 727 certified in Europe back in the 60's.
I'm frankly shocked you're so willing to jump to Boeing's defense in light of the mountain of evidence that has hitherto come to light, considering it's you they want to pin the blame on to avoid taking responsibility for what they decided to do.
Good day, sir. I only hope people take the time to do their own research.
After you've spouted invective and abuse at me? I see you've edited it out since.
> > ET302 ultimately turned the electric trim back on which was their death knell, in violation of procedures.
> No it wasn't
Wrong. Boeing OMB, dated November 6, 2018:
"In the event an uncommanded nose down stabilizer trim is experienced... do the Runway Stabilizer NNC ensuring that the STAB TRIM CUTOUT switches are set to CUTOUT and stay in the CUTOUT position for the remainder of the flight."
Followed by an airworthiness directive requiring the immediate revision of flight manuals and familiarity of pilots with this OMB.
ET302 was 10 March 2019.
It goes on to state that you should neutralize trim forces before going to STAB TRIM CUTOUT.
"Electric stabilizer trim can be used to neutralize control column pitch forces before moving the STAB TRIM CUTOUT switches to CUTOUT."
I told you before that MCAS was faulty. It's the most important link in the failure chain, but it sure is unwise to advocate ignoring the rest of the links.
As I said to you elsewhere: "The crews that crashed did not do great. But if a system is regularly putting crews to the test in a way that requires high levels of personal performance to survive, that's a bigger problem." This summarizes my thoughts on this topic. MCAS should get fixed; Boeing should be found liable for the accidents; Pilots should be better informed about the systems on their aircraft... AND we've proven that pilots that don't get recurrent training and evaluation on stab trim issues do badly with them.
> I sat down and calculated the bloody forces that would have to be applied to the screw jack to actuate against the airstream at those velocities, and the torque numbers I got without even factoring in the extra pressure from the elevators was well into the output range of an automotive engine.
OK, and humans can exert torques on trim wheels with a handle "well into the output range" of an automotive engine, too, so you've established nothing.
You've still declined to answer my simple question in the other posts, too-- which I suspect is because you don't have an answer.
So again, what was improper? Especially ET302 where they absolutely did run the checklist rather immediately and by that time it was already in a mistrim situation.