Crash: Ethiopian B38M near Bishoftu on Mar 10th 2019, impacted terrain after departure

Runaway stabilizer trim is a procedure that is required to be learned and memorized by pilots of all versions of the 737. The only thing that MCAS has done in the 737MAX is to make the event of a runaway stabilizer trim event more likely than it may have been in the past.

In other versions of the 737, runaway stabilizer trim had basically two likely causes: A defective yoke trim switch, or a defective autopilot. (There are also other, much less likely causes such as a short in the stab trim electrical wiring.) In the MAX, a third cause would be a failure of the MCAS system or its AOA sensors.

However, the procedure to correct the situation is the same for all three causes, and should have been known by the pilots. As the excerpt from the OP's article shows, the Ethiopian Airlines pilots were inadequately trained in the stabilizer trim runaway procedure. Further, after the Lion Air the Ethiopian Airlines pilots were given these specific instructions:

Just my opinion, but I think it means the stab trim motor could not have been energized by the control yoke stab trim switch when either of the cutout switches were in the off position. The powered stabilizer trim was used (as opposed to the handwheel trim) just prior to the crash. This means the power trim was re-energized by the crew in violation of procedures outlined in the flight manual. See Juan Brown’s youtube channel “blancolirio” for a pilots interpretation. While there are problems with the MCAS, these pilots violated procedure.

You are 100% wrong.

Runaway stabilizer trim does not work on the Max in the same way it works on the NG.

That is why they crashed....not because the crew were inadequately trained.

Multiple American Airline crews fought the MCAS in situations where components did not fail (like in the Ethiopian crash).

American and Boeing pilots in the simulator crashed in the Max after they reproduced the situation for both Lion Air and the Ethiopian flights using the FDR information.

So, please do not come here spouting off like any competent pilot could have handled this. When you have less than 40 seconds to recognize and take action, resulting from a component that does not exist on the NG, it is deadly and will result in many proper lawsuits against Boeing.

It seems to me four major potential factors jump out in this Ethiopian incident.

1) after using the STAB TRIM CUT OUT switch, one of the pilots returned it to its normal position. If it had been left CUT OUT, the MCAS would not have driven it to the ground. The pilots absolutely should have known this and not returned the CUT OUT SWITCH to its original position.

2) Boeing software should have monitored the single input AoA sensor to MCAS for potential failure modes. It's data values were wildly outside the any normal bounds and therefore detectable as an electronic failure from very early in the flight. The other AoA sensor could quickly have (software-wise) been deemed to be working normally/predictably to agree with the early phases of 99.98% of flights.

The MCAS should have been known to use the other AoA sensor's output and (in the longer term) put up a warning dialog with the pilots to beware of potential consequences and prompt pilots with POH information and alternatives.

Boeing software management seem potentially to be the weightiest culprits in this mix. They could and should have kept these apparent issues from crashing those two planes, (though I know less about the Lion Air flight, so maybe just the Ethiopian 737 Max 8 flight.

This vulnerability sticks out so "red-thumb" clearly that the failure of those MCAS input AoA sensors that figured in both the Lion Air crashes needs to be gone over with a microscope in so many ways!

3) There is so much "redistribution of income" potential with this seemingly small vulnerability that one must consider the potential for sabotage.

4) The corrupt FAA are a potential factor here, as are the Chinese, who were champing to be allowed to sell their licensed knock-offs to be purchased even the US Airway System. That permission would be huge! That one piece of the puzzle is so huge that it must be taken in dead earnest as a possibility! These factors were also very much in play in the not-distant past, yet before both crashes. Trump's negotiation with Chinese struggled over these questions.

FAA certification of Chinese craft have had hanky-panky going on. Other FAA corruption has been known, yet not rectified, charged, or seen people fired. Someone may well have been helping the Chinese get their way.

Ethiopian Flight 302 crashed 133 days after the Lion Air Flight that crashed on the 302nd day of the year. There are very, very few coincidences in this world, and these gematria items could be the calling card and fingerprints of the Deep State.

I thought it was fairly well established the Ethiopian pilots followed the correct procedures by turning off the stab trim toggles. Exactly why and when they turned it back on will

The prevailing theory, given the discussion in the cockpit, is that they could not turn the manual trim wheel, so they turned the Auto Trim switches back on in order to use the electric trim on the yoke.

Using the electric trim disables MCAS while you are holding the switch. But once you let go for 5 seconds, MCAS turns back on.

The electric trim barely changed the trim of the aircraft according to the FDR. That is disturbing and probably means the electric motor could not overcome the aerodynamic forces over the trim tabs.

Pilots are trained to apply electric trim, then evaluate if you need to apply more. That wait and evaluation killed them as MCAS moved the trim beyond the point where electric trim is allowed to operate.

Runaway stabilizer trim does not work on the Max in the same way it works on the NG.

In what way does the runaway stabilizer trim procedure for the Max differ from the runaway stabilizer trim procedure for the NG or the Classic?

Cite your references or don't YOU come spouting off like you understand how to fly an aircraft, let alone the 737.

Here's some light reading for you:

http://www.b737.org.uk/mcas.htm

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