Posted on 11/13/2018 1:42:33 PM PST by BenLurkin
Boeing and the Federal Aviation Administration issued directives last week telling flight crews about the system, which is designed to provide extra protection against pilots losing control. That prompted aviators, unions and training departments to realize that none of the documentation for the Max aircraft included an explanation of the system, the union leaders said.
“We don’t like that we weren’t notified,”
Few details have been released about the underlying causes of the Lion Air crash Oct. 29 in the sea near Jakarta, but Indonesian investigators say that an erroneous sensor prompted the plane’s computers to push the aircraft into a steep dive. A new safety measure added on the Max models to prevent pilots from losing control is what caused the plane to point downward, according to the FAA and Boeing.
When Boeing designed its latest version of the 737, it added the new safety feature to combat a loss of lift, which is a leading contributor to the loss-of-control accidents that by far cause the most crash deaths around the world.
Known as the Maneuvering Characteristics Augmentation System, it was added “to compensate for some unique aircraft handling characteristics,” according to a bulletin sent by Southwest’s flight operations division to its pilots on Nov. 10.
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.
(Excerpt) Read more at time.com ...
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?
From that link: “There have been 171 737 hull-losses, including 4 hijackings/bombings and 7 ground accidents. This may sound high but remember that almost 10,000 737’s have been built since 1967. This gives a 2.3% accident rate or approx 3 per year or one every 2.5 million flight hours. Furthermore, over 40% of occupants survive fatal 737 accidents.”
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.
This.
” replaced the AOA sensor”
Seems like there would be more than one of those sensors on the plane - redundancy, you know.
Exactly like in “Airframe”.
Maybe the son of the pilot was in the captain’s chair too.
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.
I don’t recall the 737, but I know the early 727s had a really bad safety reacord. It’s been a few decades, but it may have been crashes on landing.
“For all of you fly by wire fans. Your new system sucks.”
Who cares if it sucks, it’s HIGH TECH !!!!
Sure, there will be some Neanderthals not willing to give up their lives for ‘technology’, but PROGRESSIVE PEOPLE, the ones not afraid of change, will not have a problem here.
Is it really Boeing’s fault that the pilots are tight-wad non-progressive types, who value their lives above the advancement of ‘technology’? I don’t think so.
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.
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
“The condition can even lead to “excessive nose-down attitude, significant altitude loss, and possible impact with terrain,” the official noted.
Ya think?
I don’t care if this IS Boeing. Someone is responsible for this tragedy. I also cannot relieve the pilots of responsibility in failing to control the aircraft. Unless, of course, Boeing’s flight control system made that impossible as a result of its “safety feature”...
This statement is comforting and what I would expect from a well-trained pilot:
“A Boeing 737-800 Captain who works for a major US airline and has logged more than 6,000 hours of flight on this equipment tells Airways that “we train extensively on unreliable airspeed abnormals. The key is recognition, after which through power settings and ground speeds, the jet is controllable.””
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