ecblackiii Loc: Maryland

The highly publicized crashes only happened with certain third-world airlines which had previously been criticized for using flight crews that US and European airlines would not allow to fly. But that got hushed up in the third-world country's investigation of its own airline. Everyone involved wanted to avoid legal and financial liability, so they stuck it to "deep pockets" Boeing.

In fact, the MCAS is only an adjunct to the autopilot. And the autopilot is not needed to safely fly the plane. It is merely a convenient feature, like the cruise control in a car. But a normal person who discovers the cruise control is not working would simply turn it off and not keep turning it back on until he finally crashes into a tree.

When any kind of failure occurs, all pilots are taught to solve the problem by isolating and turning off whichever system caused the problem. The ordinary "redundant design" for an autopilot failure (in all planes) is for the pilot to simply turn off the autopilot and fly the airplane manually, the way they were taught in flight school. In both the crashes, the foreign pilots successfully isolated the failure when they switched off the autopilot. Once they did that the planes flew normally. But they just wouldn't leave well enough alone. Instead of flying the plane manually (which all pilots are taught to do), once the problem went away, they stupidly turned the autopilot back on, thus reinitiating the failure. I understand they did it multiple times and each time were "surprised" that the autopilot didn't work correctly. (Remember what Einstein said was the definition of "insanity"?)

In the Boeing engineers' minds (and of the FAA Engineers who examined and approved the initial MCAS design), it was inconceivable that any intelligent person (much less a supposedly professionally trained pilot) would keep turning back on an autopilot system that wasn't working properly. So, now they have had to redesign the system to anticipate really dumb decisions by poorly trained and experienced pilots of some third-world airlines.

Would I fly on a 737 Max? Absolutely, if it were flown by a major airline. Would I fly any plane of a third-world airline? Nope!

TriX Loc: Raleigh, NC

Completely agree, but that upgrade changed the flight characteristics in a way that required SW compensation in some circumstances, and the design of that compensation had a potential flaw that was not adequately communicated to the operators of the aircraft. Is that incorrect?

TriX Loc: Raleigh, NC

BUT, every other part of the autopilot, flight director, auto throttle, flight controls and communication systems of the aircraft had mechanical/electrical redundancy (that does not involve manually flying the aircraft). If the MCAS system had multiple sensors as do all of the other systems I mentioned, it may be that the issue might not have occurred. I agree that if the auto throttle and autopilot had been disengaged, the aircraft might have been able to be recovered. But it does seem that the Boeing bears SOME responsibility for the design of the system and documentation.

The NTSB response to Ethiopia’s investigation attributed the cause to:
1) “the uncommanded nose down input from the MCAS due to erroneous AOA value” and
2) “the flight crew’s inadequate use of manual electric trim and management of thrust to maintain airplane control.”

I agree. if I were still flying regularly, I’d have no qualms about flying ANY Boeing aircraft, and I would avoid third world small airlines like the plague.

ecblackiii Loc: Maryland

That’s a common misconception. The “redundancy” for an autopilot is simply the basic piloting skill of flying the aircraft manually, as one must be able to do in order to obtain a license. In the case of the Flight Director, the redundancy is in the six specialized “basic flight instruments” that all instrument-rated aircraft must have. These are the airspeed indicator, altimeter, vertical speed indicator, attitude indicator, heading indicator, turn and bank indicator (turn coordinator). The first three are powered by air pressure while the others are powered by gyroscopes. A backup to the heading indicator is the magnetic compass. With just those instruments, the plane can be safely flown to its destination.

There are really no backups to the pilot’s flight control column, rudder pedals, or engine throttles per se, but it’s hard to conceive of a pilot breaking them off. If the rudder fails, the pilot can normally control the aircraft direction with ailerons and differential engine power. In the case of hydraulic-driven systems, each engine has a hydraulic pump. Likewise, in the case of electricity there are usually multiple redundancies. Boeing planes have quintuplicate electrical redundancy—at least two generators (one on each engine), an auxiliary power unit (generator) in the tail section (normally only used on the ground), the large battery pack itself, and, if all else fails, a “pop-out” wind-driven emergency generator that normally hides within the fuselage.

There are usually multiple radios operating on different frequencies, but they normally are used for different purposes and are not really redundancies, per se. Should all radios fail, pilots are trained to use “dead reckoning” in flying the currently approved flight plan and making an approach to landing at the time specified in that flight plan.

TriX Loc: Raleigh, NC

Does the 737 not have 2 separate autopilot computers, each with an engage switch?

Artcameraman Loc: Springfield NH

Ever get the feeling that the goal of the media is to put Boing and a lot of others out of business so you know who can take over.

Canonuser Loc: UK and South Africa

As I said earlier, my grandson is a UK pilot and the pre crash information about how to fly the plane he was given was contained in one A4 sheet of paper which stipulated NO simulator training was needed. Post crash when the planes were allowed to fly again, Boeing advocated two days of simulator training.
You need to watch the film Downfall, which explains Boeing’s awful inadequacy in this situation.
Blaming the problem on foreign pilots is both ignorant and disgraceful.

ecblackiii Loc: Maryland

The same sensor input goes into each of them. So, if the input sensor for pitch is bad, both autopilots are immediately affected with the same failure. So, both should be shut off and the pilot should fly the plane manually, as taught to do in flight training.

ecblackiii Loc: Maryland

Facts are Facts!
• There are 1,126 commercial airlines in the world today.
• In the last 25 years, there have been 23 fatal crashes of 737s in the world.
• Not one of them was a passenger aircraft operated by a U.S., European, or Japanese airline!

Please learn the truth before casting stones.

ecblackiii Loc: Maryland

Breaking news, Canonuser. Both pilots fell asleep on an Indonesian airliner with 157 passengers onboard!

https://www.msn.com/en-us/travel/news/pilots-fall-asleep-in-mid-air-nightmare-aircraft-veers-off-course-with-157-passengers/ar-BB1jHhyD?ocid=hpmsn&cvid=3efeae0ec2ee4afcabd760f4c4441544&ei=45

bikinkawboy Loc: north central Missouri

Lively discussion! I guess I’m a good example of how to apply it to camera.

I normally shoot jpeg (although not normally the automatic setting). So I’m basically turning the driving over to the camera. There are times when it isn’t able to give me what I want, so I turn the knob to manual to make it do what I want it to do. I don’t want to have to make manual adjustments for every shot like in the so called good old days, but knowing what to do in those instances sure helps.

Adjusting a camera isn’t a life or death situation like it is for airline passengers, but if the automatic controls aren’t doing what they need to do, then you turn them off and do it by hand. You don’t repeatedly stick your finger into a fan and get the end chopped off, even if the guard does have holes big enough to do so. Sound like some pilots need to relearn the “once burned, twice shy” lesson.

Latsok Loc: Recently moved to Washington State.

The wheel falling off, and the plane veering off the runway are not Boeing problems; rather these are symptoms of dangerously sloppy and unprofessional maintenance procedures at United Airlines. There were other United airlines problems in the near recent times.

ecblackiii Loc: Maryland

Canonuser Loc: UK and South Africa

Apparently it did not work that way, which of course resulted in the problem. It was not possible to switch MCAS off. Clearly if returning controls to manual, which these pilots tried to do worked, the planes would not have crashed.
The film Downfall, makes this very clear.

ecblackiii Loc: Maryland

MCAS is not a piece of hardware. It is a subset of computer code within the autopilot's overall software code. Turning off the autopilot turns off all its code, including the part called MCAS.