Posted on 11/18/2018 1:19:55 PM PST by BenLurkin
One of the Max 8's new features is an anti-stalling device, the maneuvering characteristics augmentation system (MCAS). If the MCAS detects that the plane is flying too slowly or steeply, and at risk of stalling, it can automatically lower the airplane's nose.
It's meant to be a safety mechanism. But the problem, according to Lion Air and a growing chorus of international pilots, was that no one knew about that system.
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Investigators are currently examining whether an angle of attack (AOA) sensor on the outside of the Lion Air plane transmitted incorrect data that could have triggered the MCAS to force the plane's nose down.
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Investigators said that the day before the crash, the jet experienced problems with its AOA sensor, which was replaced. The last four flights -- including, crucially, the flight that crashed, according to Soerjanto Tjahjono, the head of Indonesia's National Transportation Safety Committee (KNKT) also had problems.
On Wednesday, the Wall Street Journal reported that Southwest Airlines, a US carrier that also has a fleet of MAX 8 planes, replaced two malfunctioning AOA sensors, during the three weeks before the Lion Air crash.
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A Federal Aviation Authority (FAA) emergency directive sent to all MAX 8 operators on November 7 explained that pilots can stop a malfunctioning automated system on those planes by pressing two buttons.
The FAA bulletin said that all carriers were to revise their manuals within three days. "This condition, if not addressed, could cause the flight crew to have difficulty controlling the airplane, and lead to excessive nose-down attitude, significant altitude loss, and possible impact with terrain,"
(Excerpt) Read more at cnn.com ...
lead to excessive nose-down attitude, significant altitude loss, and possible impact with terrain
If the plane is flying too slowly or steeply, and at risk of stalling, the pilot is incompetent.
I’m wondering how this is different from stick pushers that have been installed in many commercial jets for decades.
Aviation ping
I tried using it on my wife, but it didn’t help.
There will be big litigation against Boeing on this issue. Pilot error or Boeing error Training error by lion? I guess will will see it all unfold over the next 24 months. Very costly error.
For the record I flew on a SWA 737 Max in Mid October. The plane was delivered to Southwest in July 2018. Very impressive plane. The only flaw there was on my flight was no WiFi that evening from Fort Lauderdale to Kansas City. It was not a big deal. Otherwise the Plane, Pilots and Crew were great.
Pushing for “self-flying” airplanes. That’s where this is going. (to save money and maximize profit) The selling point will be that it will save lives. No it won’t. Safety features can assist pilots, not take their places.
I’m just glad they fixed (too late) that vertical stabilizer valve system. I had just flown from St. Louis, with a connecting flight, to Connecticut, when US Air 427 happened. None of my planes were 737’s on that trip, though. I was laying on the bed in my hotel room watching the news that evening.
I always had good rides on a 737, especially once the 300 series hit (long, long ago). One time they had trouble sealing the door. Looking back, I might have asked to deplane.
They are installing a device that the passengers have no idea is there, a device which adds weight and cost but you think it’s a step to maximizing profits? How do you feel about auto air bags and collision avoidance sensing?
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Obviously exists for the same reason. The fix on older craft was to verify that you are still safely flying, then disable a system by turning a switch to OFF or pulling the appropriate CB. And use a checklist.
So how dumb are todays pilots, or is the system so inaccessible that pilots are physically unable to disconnect, turn OFF or otherwise disable a malfunctioning system?
Old pilot of old times
“I’m wondering how this is different from stick pushers that have been installed in many commercial jets for decades.”
The difference is that the new system seems to be less reliable.
You know there was big trouble when one pilot on Air France 447 was pulling BACK on the joystick (SMH) while the other was pushing forward.
And by accounts, the aircraft pancaked into the ocean.
Isn’t that the flight where the pilot allowed his kid to fly the plane?
“you think it’s a step to maximizing profits”
In a novel written by a former pilot, it was said that the flight management system could fly the plane more efficiently and smoothly than the living breathing pilot.
I’d guess flight management systems are tested with all sorts of unusual conditions including malfunctioning sensors. Also, I’d guess that the plane has more than one of all of the important sensors.
A good thing to do would be to familiarize yourself with the manual of the aircraft you are entrusted with. Especially when hundreds of live count on it.
This system has a defeat switch for just this circumstance. See Juan Brown’s discription on how this workshttps://www.youtube.com/watch?v=OVmoo2dw4oU&t=0s&list=UUphqjYZxxzjNbONVmY-0J7Q&index=9 Sorry it wouldn’t hotlink for me.
“If the MCAS detects that the plane is flying too slowly or steeply, and at risk of stalling, it can automatically lower the airplane’s nose.”
Yeah, that’ll really help when you are landing and setting up your flare.
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