Trump Grounds Boeing 737 MAX 8 and 9 Jets After Two Crashes


#43

So out of honest curiosity here (and kudos to Trump regardless for appearing to act like an adult for a time) but would Trump have anything to do with this decision at all? I would imagine the nice people at the FAA said kill the plane, and Trump just notified the public. I could, of course, be wrong hence the question, but it doesn’t strike me as something that would require a decision from the very top.


#44

Given the circumstances i dont think there is anyway they can financially get away with ignoring the problem or paying to make it go away.

You can think of this as the modern incarnation of the Ford Pinto. The difference is that 100s die each occurance as opposed to 1 to 4. The math alone and the far more happy litigation paridigm will have actuaries screaming fix this ■■■■ NOW.

Personally i am quite confident this is just a bad oversight in programming code coupled with pilot training to not know when to disengage the autopilot when the plane is diving thinking it is a stall situation. Since it is a fly by wire system, the ap should disengage based on certain pilot input such as moving the yoke in some manner or other inputs. Sort of like tapping the breaks in a car turns off cruise control. But if the ap software were overengineered based on the premise that the programmers know flight operations better than the guy in the seat its possible it would not accept that input and continue on protocol hence causing the crash.

To whit in this case the software could think … the plane is gonna stall, adjust the pitch to pick up airspeed. Pilot is pulling back the yoke, but i dont know the condition of the pilot, maybe he panicked and doesnt know what he is doing. Solution, continue stall mitigation protocol, which causes the crash.

Its an interesting study.


#45

Are you familiar with Alaska Airlines flight 261?


#46

I am. It was the basis for the movie Flight, which is one of my favorite movies.

FYI i also hold a private pilots license which is mostly irrelevant to the topic since most VFR pilots dont use ap enabled planes. But i mention it because i do have an interest in aircraft in general and have a pretty decent understanding of piloting.


#47

I didn’t know they made a movie out of it, thanks. It’s a case study I’ve been working on.

I’ll defer to your expertise.


#48

They did. Of course the movie is hollywoodized. The real flight 261 never actually flew inverted and it crashed and killed everyone. In the movie the plane flew inverted and only 3 died. But the tail jackscrew controlling the horizontal stabilizer failing was the common element.


#49

Maintenance error. Drift into failure.

I think my case study says it was inverted, but I’ll have to double check.


#50

Definitely maintenance error. The first dive was mitigated by pilot input pulling the yoke completely back and holding it which took a amazing amount of effort. The 2nd dive was caused by the complete failure of the jackscrew at which point threre was no recovery possible. Essentially after the first dive the screw caught by friction due to pilot input, after that it was gone.

But no, no inverted flight happened. And logically even if inverted flight had happened even if it was a couple hundred feet above ground, the moment the plane returned to normal upright flight the plane would have still sunk nose down at the same rate or worse than it had before the inversion and crashed. In the movie after returning from inversion the plane returned to level flight which is absurd since nothing changed with the stabilizers.


#51

That can happen on a quit a few aircraft now days. On the lion air crash, pilots I know that fly them said there was a switch on throttle quadrant to turn off the over rides. I want to know what every switch does. My last type rating the instructor would get irritated that I would ask what switches did. He was a technology baby. I don’t think he could fly if it was not for the FMS.


#52

We have gotten so lazy in this era of technology we place our faith in it without question. We trust the tech but never question those who created it.

To illustrate, would you trust a fire alarm that cost $15 if it were designed by a high schooler? Probably not, but you wouldnt know it was when you walked into a hardware store and bought it on the cheap.

Obviously different situation here as aircraft parts and software arent created by idiots, but one simple oversight is enough to cause a very big problem, and reliance on technology isnt enough to mitigate it. At the end of the day the output is only as good as the input.


#53

“Many experts believe that during the first crash, the Indonesian pilots lost their battle with M.C.A.S.

Possibly because of faulty sensor readings, the automated system pushed the nose of the Lion Air plane down. The pilots repeatedly counteracted it and pulled the nose back up, only to be overridden by the system again. Each interval took about 15 to 20 seconds, leaving a repetitive signature on the data for the plane’s vertical speed.

That led to the series of variations of altitude until the pilots crashed.

The public data for the Ethiopian flight is less clear and complete, but it appears to show a similar signature — an interval where the plane was gaining altitude and then leveling out.”


#54

That’s a bit premature …


#55

That was a Douglas MD83, not a Boeing 737. That was a bad design and a lack of maintenance. This is a computer software issue. There is nothing wrong with the plane itself.


#56

I don’t see anyone arguing to the contrary. They seem to have a pretty good idea what’s going on here. Either the pilots are freaking out and crashing them fighting the computer or there’s still a software issue that needs to be addressed.

Less was known 24 hours ago and I’d say this is a prudent move. Personally I’d have leaned towards quicker action as similar as both crashes seem to have been but I’m not going to be overly critical of the delay.


#57

It is, but at least two of the reports I’ve heard/seen said they’d had the required simulator retraining. One disconcerting thing I heard is that the first officer only had 200hrs in this model where over a thousand would be required for anyone in that position in the US.


#58

Perhaps a topic of another thread, but this issue you bring up is yet another in a long line of safety precautions so easily overlooked for the bottom line.

Pilot certification can be relaxed because of a shortage in qualified pilots. In some cases regulations make absolute sense and in the case of airline pilots less is not a good thing.


#59

Not in the US. We can’t however enforce our standards on airlines operating outside of the US.


#60

Nor do we have to or should.

Grounding our flights here with this particular aircraft was a sensible thing to do so kudos to trump for doing the right thing.


#61

I don’t think the delay was a bad thing. Gave the US some time to see preliminary reports and data. I think Trump made a great call.

Personally, i think this is poorly trained foreign pilots fighting the computer system. But time will tell.


#62

It may be a combo of both computer issue and the engine forward design of the two engines and placement of the attachment point of the wings. Causing a natural pitch up of the nose, coupled with a faulty correction software glitch.