Reducing thrust would also reduce airspeed, which would reduce the nose down force; for a given trim setting, the force generated by the stab will increase with airspeed. A large stab deflection at a slow speed will be easier to control than a small one at high speed.

The Ethiopian aircraft impacted at an exceptionally high speed. The natural pilot inclination with a descent close to the ground is to add power, with the notion that excess power over trimmed speed equates to climb performance (and yes, there is a pitching moment associated with a power increase). However, increasing power in a dive, particularly with nose-down trim and increasing nose-down trim, increases airspeed and with the increase in airspeed, even if pitch trim does not change, will result in a stronger nose down tendency.

I have used this example before; I took an interview ride with the owner of a small back country operation, in a Cessna 207. The ride was simple; takeoff with full nose-up trim, fly a truncated (200') left traffic pattern, and land. Run trim full nose down, takeoff, fly a 200' right pattern, and land. His point? Keep it slow, and the trim is manageable. What he looked for was an applicant that understood that relationship.

I don't advocate that practice, but the point of the demonstration is that even in an unusual situation involving control difficulty (CG near or past limits, trim runaway, etc), there's more to consider and more available to the pilot than raw thrust or trim; a fundamental understanding of the control relationship shows that running the airplane to a high speed (eg, max power to 600+ knots until impact) may not be the best control tactic when the controls are heavy and the airplane is getting hard to muscle around.

Many years ago in Wyoming, a crew in a C-119 Boxcar had a runaway propeller, which they were unable to feather. The crew went through a series of oscillations; the propeller would overspeed, causing a great deal of drag. The engine was still running; adding thrust caused the overspeed, reducing thrust slowed the airplane, and prevented the overspeed. What the crew did not grasp was that the overspeed was largely due to higher airspeed; if the crew had slowed the aircraft, they could have used partial power on the engine. Instead, they went through a series of oscillations and eventually put the aircraft down in the high desert. The relationship between airspeed and control issues can't be overemphasized. If the speed keeps increasing and the control difficulty gets worse, perhaps speed increase (and the factors that are contributing to it) are not the best course of action.

If indeed one has cut off power to the elevator trim due to unwanted movement, restoring that power may not be in one's best interest.

MCAS exists for design certification purposes within a specific set of conditions in terms of automation, angle of attack, and aircraft configuration. Pitching moment due to thrust increase or reduction occurs regardless, but the pitch moment due to thrust change may be the more minor issue compared to other players in this case.

Maybe plummeting towards the ground with insufficient pitch up response?

Yes they could have spun the wheel by hand, but maybe they didn't think that was fast enough?

From what I have read there was a procedure taught to 737 pilots some decades ago that could have addressed the issue of being unable to move the trim wheel due to high aerodynamic forces at high speeds. It boils down to releasing pressure on the yoke in order to be able to move the trim wheel. However, this procedure is no longer taught due to its antiquity and the unlikelihood of its ever being required. My guess is that the pilots found their efforts to manually move the trim wheel weren't working and they finally gave up on it, resorting to the only other tool they knew of that could move the stabilizer.

There's plenty of blame to throw around here. Neither Boeing nor the pilots are without fault, as is often the case in serious accidents. Boeing gave the pilots an awful system and inadequate systems knowledge, training, and procedures to deal with what they eventually faced. The pilots failed to control airspeed and thrust while dealing with the emergency situation.

I hope that I would do better if placed in the same situation. But as a fellow professional I think it's arrogant to claim that I would do better without having been in that situation myself. We all are human and have a limited capacity to process information. Almost every crash of the past several years dating all the way back to AF 447 tells us that pilots are capable of being overwhelmed and losing their fundamental flying skills when presented with a startling or time pressured emergency scenario. Should we do better? Yes. Will we? Only those of us who have been through similar scenarios and come out alive can make that claim with certainty.

The “plummeting towards the ground” did not start until after the cutout switches were reset. And even then, there was no effort to trim nose up beyond two quick clicks of the yoke switches.

Answers many, if not all questions in my mind.

https://www.youtube.com/watch?v=HBqDcUqJ5_Q

Please someone, post a video of themselves "easily" spinning the wheel back, with trim position starting in the full down position, speed at or near VMO, and being in air as denses as it is a 1000 ft msl/agl. Think about the bind force on the jack screw you are trying to overcome in that situation.

Of course their efforts weren't working. They had the long forgotten throttles locked in the forward position, driving the aircraft to and past VMO. They needed to SLOW DOWN - just like anyone else trying to deal with a runaway stab situation and requirements to use the manual trim wheels. That was the "tool" to which they need to resort - flying the aircraft. Yoke, throttles, pitch, power, CRM... basics. Turning a failed system back on was not the "only other tool".

It's amazing anyone here is actually claiming that it's understandable that a fully trained 737 crew of a national airline can ignore their airspeed during this event for 6 minutes. There's no excuse. None.

So which accidents that have happened lately do you find excuses for?
Let's do past 20 years and skip 9/11. Which ones were handled correctly?

You seem to have a problem with someone calling a spade a spade.
I'm not excusing any accidents in particular. Many here, including you, seem to want to give these guys a pass and put all the blame on Boeing. I'm just not feeling as forgiving and "it could happen to anyone" as some of the bleeding hearts here seem to be. Based on the clear evidence provided by the FDR, it's my opinion (and I'm not the only one) that these two pilots screwed up badly. The media firestorm and the myriad of "experts" spouting BS about MCAS have turned this into a sympathy party for pilots who should have been able to handle a relatively basic malfunction.
Boeing did a terrible job with this system and they should share the blame for these accidents because a single point, single input failure is an amazingly stupid design. But all that did was drastically raise the probability of a runaway stabilizer event happening on these aircraft. That malfunction is not an unrecoverable event and in the hands of a competent crew should have ended in a safe landing. If you actually think that this outcome could happen to you under the same circumstances, then you really should choose another line of work.

I believe the ones that were handled correctly resulted in a safe landing with little to no media coverage.


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