[BenLurkin]

Just d-mn

[csvset]

So, in this case, RTFM was useless ?

[Paladin2]

Who’s flying this plane anyway?

[Berlin_Freeper]

Trouble me

[z3n]

Loss of lift, or uncontrollable plunge? hrmmm...

Putting the aircraft into a dive to regain speed across the wings without pilot input sounds like a great idea, and I agree with it, because time is off the essence in a stall situation, so I’m guessing that one of the software checks would be for available altitude, but you’d think they’d take into account the possibility of equipment failure. This is done all the time. If you go into a dive and your air speed readings don’t change, there should be a time-out on the maneuver.

[TADSLOS]

[Moonman62]

A bit more info from here:

https://www.seattletimes.com/business/boeing-aerospace/u-s-pilots-flying-737-max-werent-told-about-new-automatic-systems-change-linked-to-lion-air-crash/

A former Boeing executive, speaking on condition of anonymity because discussion of accident investigations is supposed to be closely held, said that Boeing engineers didn’t introduce the change to the flight-control system arbitrarily.

He said it was done primarily because the much bigger engines on the MAX changed the aerodynamics of the jet and shifted the conditions under which a stall could happen. That required further stall protection be implemented to certify the jet as safe.

[smokingfrog]

https://onemileatatime.com/boeing-737-max-safety/

[Moonman62]

This makes Boeing look bad, but Lion Air replaced the AOA sensor the day before so I think there’s going to be other causes, too.

[Arlis]

This is why I’ll never buy one of the new cars that can take over your brakes and steering without your approval.....”to avoid an accident”.......a disaster waiting to happen.......nothing made by man is perfect.......

[Politically Correct]

There needs to be a big red button that lets the pilot take complete control without the benefit of the computer.

[Rio]

Give me a good old-fashioned stall warning, and I’ll push the nose down myself.

[Revel]

Compare this to sudden acceleration in Toyota’s.

For all of you fly by wire fans. Your new system sucks.

[Reno89519]

Bad for Boeing. BTW, didn’t the earliest 737 also have similar or rather deadly crashes—nosediving into swamp and such? I remember for several years wanting to avoid accident prone 737. Maybe should again?

[Reno89519]

Here is list of Boeing 737 crashes based on write-off of the plane (e.g., beyond repair). 168 planes lost. Interesting, still reading it.

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

[DiogenesLamp]

When the system senses the plane is close to losing lift on the wings, it automatically commands a lowering of the nose to counteract the risk. However, the chief sensor used to predict a loss of lift — known as an angle-of-attack vane — was malfunctioning on the Lion Air flight. It essentially tricked the system into ordering a sharp dive.

Of all the stupid ideas. Bad sensor on a system that has actual control of the aircraft is what killed these people. Idiot who thought this was a good idea is ultimately responsible.

System should have warned pilots. Pilots should have been able to override system.

[fruser1]

Exactly like in “Airframe”.

Maybe the son of the pilot was in the captain’s chair too.

[PAR35]

So the crash was caused by a Boeing designed in feature that the pilot can’t override?

Let’s see what the Boeing cheerleaders here have to say. I do wonder how many of them are on the Boeing payroll. I expect we won’t hear from them on this thread.

[ThunderSleeps]

Ok, so it sounds like the intent is to create an automated low speed stall recovery system. The usual means of recovering is to lower the nose first, once a favorable angle of attack is achieved gently add thrust. Note that with the engines below the wing on the 737 adding thrust sharply can tend to push the nose up. So as I understand it, adding thrust is a second stage of the recovery. You are going to trade some altitude to regain airspeed and control.

So I'll bet Boeing engineers were trying to automate that procedure - have the computer recognize a low speed condition and automate at least the initial stages of the recovery maneuver - namely reduce AOA. All well and good but, this raises several questions:

Does initiation of the maneuver depend solely on one sensor? Did they not anticipate a faulty sensor?

Once initiated, shouldn't there be limits to how much nose-down pitch the system is allowed to command?

Once initiated, shouldn't a low AGL override this so as not to dive into the ground? (ie. the old "controlled flight into terrain" problem)

It seems disturbing that this automated system can take over and initiate substantial maneuvers even when the pilots are manually flying the aircraft. (ie. autopilot off)

It seems even more disturbing that the actions of this system were not briefed and training provided to air crews.

[Ozark Tom]

No pilot wants his fate undermined by an aircraft that fails to respect the pilots authority. At least it isn’t the French Government deciding the pilot is expendable in the courts, falsifying the flight recorder data to save their aircraft company.

http://www.crashdehabsheim.net/CRenglish%20phot.pdf

[logi_cal869]

https://www.flyingmag.com/blogs/fly-wire/missing-instrument