4 ms·

Setting autopilot immediately on takeoff is very tempting because it massively reduces workload vs hand flying during a critical flight stage (high workload). S

Setting autopilot immediately on takeoff is very tempting because it massively reduces workload vs hand flying during a critical flight stage (high workload). So there’s a strong temptation to do this. But if you miss a few checklist items and don’t fully understand the systems, this is the result. The numbers seem to indicate they didn’t immediately recover the situation either I.e immediately switch to hand flying and adjust throttle. At 1000 ft they’re still 80 knots too fast. I also wonder about the decision to continue on after overspeeding the flaps. Takeoff flaps with full load on the 777-300ER is 15 degrees. Max airspeed with that setting is 215. They hit 260 at 175ft.

jacquesm 5y ago
All hail engineering safety margins I guess. Hope they check out that plane, especially anything related to flap mounting and actuating as well as the flaps themselves. That's a lot of force. edit: omegant points out that the tires have been over-speed: https://news.ycombinator.com/item?id=29763515 https://news.ycombinator.com/item?id=29763515
deleted 5y ago
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oceanplexian 5y ago
I have an autopilot in my small single-engine GA aircraft and don’t even think about touching it until long after takeoff when I’m comfortably at pattern altitude. The reason being I’ve read way too many NTSB reports when the pilot engages the thing 50ft after takeoff, it has a mind of its own and the plane goes careening into the ground. There are “failsafes” built in, for example you can easily overpower it with control forces or disengage it, but that’s one more problem you don’t want to deal with during a critical phase of flight.
- mmaunder 5y ago
  Yeah I got into that nasty habit in sims using pilotedge because it’s easier to switch to departure/approach on the climb. Had to break that for real life. (I’m also a GA PPL)
kortilla 5y ago
This wasn’t an autopilot problem. The problem occurred while still in takeoff roll.
- YPPH 5y ago
  >This wasn’t an autopilot problem. The problem occurred while still in takeoff roll. Just an amateur here, I could be wrong. It is true that according to the article, autopilot was not engaged and the pilot was following the flight director during the take off roll. However, had the pilots obtained positive climb, and satisfied autopilot activation requirements, and turned it on, wouldn't it be catastrophic if the altitude had not been set properly? [0] [0] See, eg, https://www.bbc.co.uk/news/uk-46137445 https://www.bbc.co.uk/news/uk-46137445

jacquesm 5y ago

All hail engineering safety margins I guess. Hope they check out that plane, especially anything related to flap mounting and actuating as well as the flaps themselves. That's a lot of force. edit: omegant points out that the tires have been over-speed: https://news.ycombinator.com/item?id=29763515 https://news.ycombinator.com/item?id=29763515

deleted 5y ago

[deleted]

oceanplexian 5y ago

I have an autopilot in my small single-engine GA aircraft and don’t even think about touching it until long after takeoff when I’m comfortably at pattern altitude. The reason being I’ve read way too many NTSB reports when the pilot engages the thing 50ft after takeoff, it has a mind of its own and the plane goes careening into the ground. There are “failsafes” built in, for example you can easily overpower it with control forces or disengage it, but that’s one more problem you don’t want to deal with during a critical phase of flight.

mmaunder 5y ago
Yeah I got into that nasty habit in sims using pilotedge because it’s easier to switch to departure/approach on the climb. Had to break that for real life. (I’m also a GA PPL)

kortilla 5y ago

This wasn’t an autopilot problem. The problem occurred while still in takeoff roll.

YPPH 5y ago
>This wasn’t an autopilot problem. The problem occurred while still in takeoff roll. Just an amateur here, I could be wrong. It is true that according to the article, autopilot was not engaged and the pilot was following the flight director during the take off roll. However, had the pilots obtained positive climb, and satisfied autopilot activation requirements, and turned it on, wouldn't it be catastrophic if the altitude had not been set properly? [0] [0] See, eg, https://www.bbc.co.uk/news/uk-46137445 https://www.bbc.co.uk/news/uk-46137445