Boeing 737 MAX MCAS

That's not really what happened here.If you know what's going on, MCAS is quite safe - there are two highly visible switches that kill electric trim completely (thus disengaging MCAS) and allow the pilots to take manual control. Activating these switches is a memory item (i.e. pilots have to memorize the checklist) for runaway trim and would be universal across 737 variants.Unfortunately, it appears that both the Lion Air pilots and the Ethiopian Airlines pilots did not recognize

The problem is they don't know MCAS exists so it looks like the trim system has failed and is running away so the normal and natural solution is to disable electronic trim.Had they known about MCAS they could have potentially known they could override it then disbale the trim system but that information was hidden by Boeing so they didn't do it..

No amount of "stability" is going to correct for a system constantly adjusting your nose to point into the floor.All mcas does is adjust the offset on the elevator.it is a failure of UX and oversight. Pilots weren't trained, Alarms weren't installed. Its as simple as that.

Your suspicion is correct.FAA rules require on all planes that the control stick takes more and more pressure to pull back as the plane approaches stall.The 737 MAX doesn't meet this requirement, apparently it gets easier to pull the stick back as it approaches stall due to engine nacelles. This is what MCAS fixes, as the plane approaches stall, it adjusts trim to provide that extra back-pressure on the stick.No amount of additional pilot training will allow the plane to fly withou

Everything I wrote is true. The LA crew restored normal trim 25 times, but never thought to turn off the stab trim system. The trim cutoff switch is right there on the center console within easy reach for just that purpose.The EA crew oversped the airplane (you can hear the overspeed warning horn on the CVR) and did nothing to correct it. This made things worse. They were also given an Emergency Airworthiness Directive which said to restore normal trim switches, then turn off the trim system.

Prior to MCAS, most causes of trim runaway could be stopped by countermanding it with the control column, but, because MCAS is intended to avoid a pilot-commanded (though presumably accidental) stall, this is not the case for MCAS:"[MCAS intervention] can be stopped by the pilot counter-trimming on the yoke or by him hitting the CUTOUT switches on the center pedestal. It’s not stopped by the pilot pulling the yoke, which for normal trim from the autopilot or runaway manual trim trigge

This article seems to focus on things from a perspective of things from a small plane pilot. So a little wider perspective might be helpful.A 737 first off is not a Cessna like the author mentions flying. You do not get to use direct inputs easily nor do you want to have to fight stab trim because the force on the stabilizer control surfaces is muuuch higher than those on a slower flying plane. Because of this, when the 737 came out there were designs for trim systems that can help. These sys

The issue with the MCAS-fiasco was that it (by design) was not communicated to the pilots, so when it failed, they didn't know immediately what to do. If they had known, they would have cut out the trim motor and left it off and trimmed manually until landing. In the accident flight, the crew repeatedly turned on and off the electric trim and never figured out why it started moving the trim every time they turned it on again (though, yeah, it's an open question why they did this more t

The aircraft flies fine. MCAS is a stability control system that applies in certain cases (full power, high angle of attack) where the nose pitches up. It may lead to a stall but that's not what it's correcting for and it doesn't just happen during level flight. If the MCAS system was disabled then pilots handle it manually. Trim is not an exotic concept and just takes training and understanding of the operating characteristics.Airliners are very safe. They're not i

In theory, nothing here is obscure. Trim is a control that airplanes have that cars don't. It's a very basic control, it's right there on the control column. A mechanical or computer failure could cause the plane to mistrim itself, so one of the most basic emergency responses that every airliner pilot knows is how to disable the auto-trim and fix it manually. MCAS is a new way for mistrim to happen, but there were already many others before.It sounds like the main issue is