The have zero points of failures that are classified as single-point-of-failure.
Once in a while, the classification turns out to be incorrect, as seen in the 737 MAX crashes, especially the first one.
Boeing still should never have had the MAX system rely on only one AOA sensor.
Were these pilots trained with the new procedure and the other pilots who died not trained?
They trimmed it back to normal a couple times, then just turned it off.
Sounds too simple to be true, but it is true. There's a toggle switch on the console that cuts off power to the trim system. It's there in case of runaway trim.
The thing is, this revealed a vulnerability: real pilots in runaway trim scenarios do not do nearly as well as they do in training. And 737MAX ended up testing crews with runaway trim scenarios at a much higher rate than they had been at the past. Some crews failed.
Safer to say that they're designed and certified attempting to have no single points of failure.
E.g. the MD-83 stab trim jackscrew system. Two nuts were used on the acme screw, on different portions of the screw, driven by redundant gearboxes and motors: no single point of failure! But there were common-mode failures stripping the screw and nuts.
You blow a fuel pump and can’t fuel the engines.
Wings fall off.
I dunno. I can think of a bunch of failure points on a modern airliner.
not catastrophic failure, like you get with a rocket or a helicopter.
https://theaviationist.com/2014/09/15/f-15-lands-with-one-wi...
Not as small of a risk as you’d expect (though not anything to seriously worry about). This metal fatigue grounded a large chunk of the US training fleet and similar cracks were frequently found in other Piper Arrows (including ours).
How many cycles does the airframe have to go through in order for this to become a problem? I tend to think that if the FAA gave a shit about general aviation maybe we wouldn't be flying planes from the 1960s
My dad's B-17 in WW2 was scrapped after 30 missions, it was considered worn out.
I discovered this when trying to understand what the barking noise is on airbus planes.
And as for “the wings fall off” part, makes me remember a quote of an engineer I once read that goes something like this: “The wings are the strongest part of the airplane. If you worry about them ripping apart or falling off, you have way bigger problems than that, like the rest of the plane missing”.
https://www.wired.com/images_blogs/autopia/2010/03/index.jpg
I did the calculations for the 757 elevators to show it wouldn't flutter. And yes, it was also verified on the test stand.
https://taskandpurpose.com/history/1983-negev-mid-air-collis...
- https://theaviationist.com/2017/08/16/the-crazy-story-of-the...
- https://en.wikipedia.org/wiki/Fairchild_Republic_A-10_Thunde...
Right. But the plane drops oxygen masks and goes down to a lower altitude.
> You blow a fuel pump and can’t fuel the engines.
Multiple fuel pumps and multiple gas tanks.
> Wings fall off.
Wings have dual internal structure.
> I can think of a bunch of failure points on a modern airliner.
No single point of failure is an FAA requirement.
http://www.slate.com/blogs/the_eye/2015/06/25/air_france_fli...