3 ms·
Not an expert, but it seems very clear to me that autothrottle is not intended to disengage when you press the takeoff/go around button. The whole point of that
by amenhotep 2y ago
Not an expert, but it seems very clear to me that autothrottle is not intended to disengage when you press the takeoff/go around button. The whole point of that button is that you press it when you need to take off or go around and the plane attempts to set itself to a configuration where as long as you point the nose in the right direction then that should happen.
But it does rather sound like it was an expected behaviour. The system has a history of nuisance disconnects, the manufacturer recommends that you reject takeoff when that happens, and for some reason instead of doing that, the crew reacted to the disconnect warning by pressing the button again and, at that point, trusting that it was engaged and working. My reading of that is that the plane regularly has an A/T fault that can be fixed by simply pressing the button again, so this crew has developed a habit of doing that, but this time it was a different fault with different behaviour that their usual fix didn't work for, and they just failed to notice.
The report is clearly limiting itself to describing the difference between what actually happened and what the procedures say should happen, rather than speculating about what the pilots were thinking, but that's the only way it makes sense to this very much not expert that you shouldn't pay too much attention to.
- Dalewyn 2y agoWhat's damning about the pilots is they utterly failed to monitor their engine gauges, which for those who don't know are always prominently displayed on one of the big displays near the center of the instrument panel and easily visible to anyone anywhere in the cockpit. Takeoff is by far the most stress the engines will endure during a nominal flight, it is imperative that the engines are monitored closely during takeoff in case they fail so the pilots can respond immediately. We're talking Basic Flying 101 here and these guys failed it.
- ratg13 2y agoFailed to monitor their gauges and failed to do their pre-flight checklists. They might be piloting a shit vehicle, but they put no effort into doing their jobs.
- NikkiA 2y agoIt is intended to disengage upon any physical movement of the throttles. Normal usage of the TOGA buttons would be to push them and not move the throttles - assuming the throttle has normal non-worn or adjusted throttle friction. Abnormal usage may well be that the throttle friction has worn or has not been adjusted by maintenance (afaik it's not crew-adjustable on boeing aircraft as it is on smaller light airliners), and thus pressing TOGA may shift the throttle lever enough to disengage A/T.