Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Incident: American B38M near Nassau on Mar 29th 2021, pitch trim issue/failure

avherald.com

Post reply on HN
Print view View original

41–50 of 125 posts

Re: Incident: American B38M near Nassau on Mar 29th 2021, pitch trim issue/failure

#41

Post by na85 »

mypalmike wrote: post #40
na85 wrote: post #20

Earlier quoted context omitted.

Aerospace engineer here. From TFA: >A component of the main electric trim system became inoperative. Our pilots ran the appropriate checklist, which included manually trimming the aircraft. They returned to MIA and landed uneventfully. The issue was not related to MCAS. That statement is from the airline, not from Boeing, so I'm more inclined to trust it. Additionally, if the airline lies and it turns up on an airwor…

These common imperceptible failures... Do they involve the aircraft turning around and flying an hour back to the departure airport?

That would strain the definition of "imperceptible", wouldn't it?

My point is that aircraft break all the time. Once in a while they break in such a way that they need to return to base. This wasn't an MCAS failure.

Re: Incident: American B38M near Nassau on Mar 29th 2021, pitch trim issue/failure

#42

Post by ilrwbwrkhv »

cratermoon wrote: post #17
geocrasher wrote: post #15

Earlier quoted context omitted.

MCAS was only installed to cover up aerodynamic changes (not flaws) that would have required greater recertification and retraining of pilots. To save that expense, they covered it up with MCAS so they could say "See, it's just another 737!" which caused all the issues we know so much about.

No, they are legit flaws . https://www.business-standard.com/article/international/boei...

Yup never flying Boeing again. Airbus all the way.

Re: Incident: American B38M near Nassau on Mar 29th 2021, pitch trim issue/failure

#44

Post by slacktide »

mypalmike wrote: post #40
na85 wrote: post #20

Earlier quoted context omitted.

Aerospace engineer here. From TFA: >A component of the main electric trim system became inoperative. Our pilots ran the appropriate checklist, which included manually trimming the aircraft. They returned to MIA and landed uneventfully. The issue was not related to MCAS. That statement is from the airline, not from Boeing, so I'm more inclined to trust it. Additionally, if the airline lies and it turns up on an airwor…

These common imperceptible failures... Do they involve the aircraft turning around and flying an hour back to the departure airport?

Yes, they do. I suggest that you set avherald.com as your homepage for a week, and learn how common air turnbacks and diversions are.

Re: Incident: American B38M near Nassau on Mar 29th 2021, pitch trim issue/failure

#46

Post by geocrasher »

cratermoon wrote: post #37
geocrasher wrote: post #24

Earlier quoted context omitted.

LOTS of aircraft have a tendency to pitch up or down based on throttle. This isn't unique to the 737 MAX. A quick google on "thrust line pitch moment" gave me this: https://www.homebuiltairplanes.com/forums/threads/thrust-ang... " I want to adjust the thrust angle from where it was (0° with respect to the chord line) to reduce the downward pitching moment when thrust is added (or more importantly the upward pitch mom…

Not many passenger aircraft have a tendency to pitch up to the point of stalling, though.

Neither does the 737 MAX.

Re: Incident: American B38M near Nassau on Mar 29th 2021, pitch trim issue/failure

#47

Post by manigandham »

cratermoon wrote: post #37
geocrasher wrote: post #24

Earlier quoted context omitted.

LOTS of aircraft have a tendency to pitch up or down based on throttle. This isn't unique to the 737 MAX. A quick google on "thrust line pitch moment" gave me this: https://www.homebuiltairplanes.com/forums/threads/thrust-ang... " I want to adjust the thrust angle from where it was (0° with respect to the chord line) to reduce the downward pitching moment when thrust is added (or more importantly the upward pitch mom…

Not many passenger aircraft have a tendency to pitch up to the point of stalling, though.

It does not just pitch up randomly. It does pitch more than other 737s due to engine size and placement, but that's just the specific behavior of this plane.

Stalls are not a serious problem, they're basically the first thing pilots learn to solve. And there are plenty of aircraft that are more challenging to fly. That's what training is for.

The real issue is that pilots should have full understanding of the behaviors of the airframe instead of relying on software to change it. Especially when they don't have full understanding of the software either, and the system can both override manual inputs while being susceptible to faulty sensors.

Re: Incident: American B38M near Nassau on Mar 29th 2021, pitch trim issue/failure

#48

Post by airhead969 »

scrollaway wrote: post #35
airhead969 wrote: post #30

Earlier quoted context omitted.

I wonder if people realize it's sarcasm. Nope. - Poe's law

How about scrollaway's law of post quality: if your sarcastic post sounds believable enough for Poe's law, it's a shitty post no matter how it's interpreted.

Sounds believable to whom? You're assuming an absolutist perspective of inference.

Sarcasm's law: without a tell, it doesn't always come across as sarcasm without common sense. The latter is often missing these days, hence Poe's law.

internet's law: The average level of common sense, intelligence, sense of humor, benefit-of-the-doubt, and decency decays over time.

airhead's law: Quality sarcasm poetically-highlights an insight rather than ejaculates (meaning no. 2) a humorous quip.

Re: Incident: American B38M near Nassau on Mar 29th 2021, pitch trim issue/failure

#50

Post by BenoitP »

"- A component of the main electric trim system became inoperative. Our pilots ran the appropriate checklist, which included manually trimming the aircraft. They returned to MIA and landed uneventfully. The issue was not related to MCAS."

I don't get it. It is common for other airliners to rely systematically on trimming? Do other airliners have similar 'correcting' systems as MCAS?

Post reply on HN