3 ms·
> unlike on a Boeing (at the time at least) where they're physically connected so you can't have contradictory inputs in the first place I don't know if it's t
by cesarb 3y ago
> unlike on a Boeing (at the time at least) where they're physically connected so you can't have contradictory inputs in the first place
I don't know if it's true, but I recall reading somewhere that this physical connection is a breakable link, so if one of the controls gets stuck the other control can still be used to fly the airplane (after some application of strong force to break the connection).
- f1shy 3y agoYes it is true. The force needed is pretty high.
- immibis 3y agoIt also caused one accident, where both pilots thought the controls were jammed because the other pilot was pulling in the opposite direction. This is no better than averaging. At least Airbus gives an alarm.
- ImPostingOnHN 3y agoWhich accident was that? Thanks!
- immibis 3y agoDon't remember, sorry.
- ImPostingOnHN 3y agoI couldn't find any evidence of it happening either, which makes sense, a system which gives feedback there's a problem intuitively seems better than one which doesn't.
- inferiorhuman 3y agoa system which gives feedback there's a problem intuitively seems better than one which doesn't. Except that your intuition isn't always correct. Airbus throttle levers don't move on their own, Boeing throttle levers (at least pre-FBW) were mechanically linked to the control system and would move in response to computer inputs. Sounds safer, right? Look at the Sriwijaya Air 737 crash (among others). Even with the throttle levers showing wildly asymmetrical thrust, when the automation gave up the pilots didn't notice, didn't react properly, and crashed the plane.
- ImPostingOnHN 3y agoSticks (not throttles) mechanically linked to each other do indeed give feedback indicating there is a problem when the two sticks conflicted, compared to, it seems, the Airbus concept, which did not. I see no reason the intuition here isn't correct: it's better to know about this problem when flying than to not know about it. Stories about throttles or automation are a distraction from what we're talking about: mechanically linked sticks. On that note (back on topic), I still couldn't find any evidence of the crash mentioned above, but maybe I'm just searching wrong. Does anybody know about this crash supposedly caused by Boeing sticks being mechanically linked?
- inferiorhuman 3y agoSo-called "side stories" about throttles that provide feedback are entirely relevant because they address the issue at hand: the supposed benefits of physical feedback in the controls. The Sriwijaya crash is additionally relevant as it happened during a phase of flight where someone's hands were likely to be on the throttle quadrant in the first place. If you're going to double down on the idea that somehow feedback in a control column is a wildly different affair than feedback in the throttle quadrant, Air France recently had a go around where the two pilots provided opposing inputs without realizing it. The inputs were forceful enough to un-synchronize the controls, so yeah, physical feedback is less helpful than one's intuition suggests. With Air France 447, there should've been an annunciator that conflicting input was being provided (as well as the ability to lock out one set of controls). However, when you're task saturated it doesn't matter what you're flying — there are plenty of things you're going to miss. Were there strong benefits to feedback (or lack thereof) on FBW controls there would be some sort of mandate from the FAA or EASA one way or another.
- Lt_Riza_Hawkeye 3y agoIt was an air france accident, it happened twice (both times to air france), one time it resulted in an accident, then it happened again later but it only resulted in an extremely stressful go around