3 ms·

Hum, it doesn't seem like a lot. Maybe I missing something, but looks like a software update to make MCAS more robust. And if it bug, raise an alarm and flight

Hum, it doesn't seem like a lot. Maybe I missing something, but looks like a software update to make MCAS more robust. And if it bug, raise an alarm and flight-crew operating procedures should be (?) to deactivate MCAS and fly without ? Could pilots actually fly the plane without MCAS ? It must feels like an entirely different aircraft.

rootusrootus 6y ago
> It must feels like an entirely different aircraft No, if MCAS is disabled then the vast majority of the time it will fly just like normal. MCAS is only there to adjust flying characteristics when the wing is at a high angle of attack.
- linuxftw 6y ago
  > only there to adjust flying characteristics when the wing is at a high angle of attack. No, that's a Boeing talking point. It's there to prevent the aircraft from stalling, not to 'adjust flying characteristics.' The nose pitches up during high thrust, MCAS kicks in to to counter what the pilot is doing (stick and thrust) so the plane doesn't stall.
  - rootusrootus 6y ago
    All planes with low mounted engines (read: most current jet airliners) pitch up with increased thrust. It's not controversial, and pilots deal with it routinely. MCAS does not activate under normal flight conditions.
    - linuxftw 6y ago
      > MCAS does not activate under normal flight conditions. This is entirely the problem. If MCAS operates, you're already doing something wrong. It was required in the first place because the likelihood of pilots doing something wrong is high. Now, instead of MCAS backing up the pilot's bad decision making, it might cut out at a critical moment. We already know that Boeing revised (increased) the authority of MCAS without notifying the FAA because testing found the MCAS to be inadequate initially. You can't simultaneously need MCAS and be okay with it being disabled intermittently. Those two things are directly at odds.
  - himinlomax 6y ago
    It's not there to prevent stalling, except in as much as pitching the plane too much does eventually result in stalling; however any pilot will have pushed the stick or trimmed long beforethat. It's there to make the plane behave exactly like an older model at a high angle of attack, to counteract the engines being further forward than those models.
racnid 6y ago
Yes, to my understanding the only issue a pilot would run into with MCAS disabled and neutral is decreasing control forces at high angles of attack. The FAA requires control forces to monotonically increase with angle. I say "only" but that probably makes for a very weird feeling airplane to fly; how dangerous that actually is for a trained pilot I can't answer for sure but my gut and experience tells me not very.
- salawat 6y ago
  It is a specifically enumerated disqualification for civil transport aircraft, created in a time where all aircraft were flown by hand. I'd be comfortable with taking it as a given this is not an avenue worth excavating.

rootusrootus 6y ago

> It must feels like an entirely different aircraft No, if MCAS is disabled then the vast majority of the time it will fly just like normal. MCAS is only there to adjust flying characteristics when the wing is at a high angle of attack.

linuxftw 6y ago
> only there to adjust flying characteristics when the wing is at a high angle of attack. No, that's a Boeing talking point. It's there to prevent the aircraft from stalling, not to 'adjust flying characteristics.' The nose pitches up during high thrust, MCAS kicks in to to counter what the pilot is doing (stick and thrust) so the plane doesn't stall.
- rootusrootus 6y ago
  All planes with low mounted engines (read: most current jet airliners) pitch up with increased thrust. It's not controversial, and pilots deal with it routinely. MCAS does not activate under normal flight conditions.
  - linuxftw 6y ago
    > MCAS does not activate under normal flight conditions. This is entirely the problem. If MCAS operates, you're already doing something wrong. It was required in the first place because the likelihood of pilots doing something wrong is high. Now, instead of MCAS backing up the pilot's bad decision making, it might cut out at a critical moment. We already know that Boeing revised (increased) the authority of MCAS without notifying the FAA because testing found the MCAS to be inadequate initially. You can't simultaneously need MCAS and be okay with it being disabled intermittently. Those two things are directly at odds.
- himinlomax 6y ago
  It's not there to prevent stalling, except in as much as pitching the plane too much does eventually result in stalling; however any pilot will have pushed the stick or trimmed long beforethat. It's there to make the plane behave exactly like an older model at a high angle of attack, to counteract the engines being further forward than those models.

racnid 6y ago

Yes, to my understanding the only issue a pilot would run into with MCAS disabled and neutral is decreasing control forces at high angles of attack. The FAA requires control forces to monotonically increase with angle. I say "only" but that probably makes for a very weird feeling airplane to fly; how dangerous that actually is for a trained pilot I can't answer for sure but my gut and experience tells me not very.

salawat 6y ago
It is a specifically enumerated disqualification for civil transport aircraft, created in a time where all aircraft were flown by hand. I'd be comfortable with taking it as a given this is not an avenue worth excavating.