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It seems that flight planning is done on the basis that the loss of all flight computers is possible, and to make sure that your runway is long enough to accomm

It seems that flight planning is done on the basis that the loss of all flight computers is possible, and to make sure that your runway is long enough to accommodate that situation. So thankfully the loss of all three computers isn’t inherently dangerous, and is demonstrated by this incident. Based on my reading of the report the primary take away from this (apart from a an issue with the flight computers software), is that flight plans aren’t and prep by the airport wasn’t conservative enough, so they ended up with slightly less safety margin than they expected in this scenario.

ncmncm 5y ago
> loss of all three computers isn’t inherently dangerous You seem to be using a different definition of "dangerous" from the rest of us. Loss of systems that pilots are used to depending on is inherently dangerous. After that, degrees of luck, skill, and conservative planning become major factors in the outcome. The loss of spoilers and reversers is itself dangerous. In slightly different conditions, e.g. snow, the aircraft would not have stopped where it did. There was a Lockheed aircraft that ran off the end of a runway at an above-usual touchdown speed: the spoilers would not go up because for lack of weight on wheels, and brakes had no traction because spoilers were not up.
- avianlyric 5y ago
  I don’t know what to say. Pilots are trained for this exact situation, flight plans are designed for this situation. Every reasonable measure is taken to ensure that this exact situation isn’t unnecessarily more dangerous than it absolutely needs to be. As proven by this exact incident. You can talk about hypotheticals like snow, but this is a commercial airport. They will either have snow clearing equipment or they’ll redirect planes if they can’t clear the snow. It’s also Taipei where it basically never snows around the city. Simply put if it was unsafe to land this plane in this state with snow (and snow was believed to fall that day), then the plane wouldn’t even take off. Lockheed aircraft aren’t passenger airlines, they have a completely different risk profile and risk appetite. I imagine Lockheed aircraft occasionally get taken down my enemy fire, but we don’t build commercial aircraft to handle that situation.
  - ncmncm 5y ago
    "[Not] unnecessarily more dangerous" is very far from the same as "not dangerous". If you cannot imagine this identical failure occurring at a different airport, in different ground conditions, I don't know what to say. You might as well say Sully splashing down in the Hudson without loss of life was unsurprising because he was trained for emergencies. (And, incidentally, airlines do not, in fact, train pilots for "all engines failed"; it is considered too unlikely and too unsurvivable.) Lockheed did make many, many passenger aircraft, and the failure I cited was, in fact, in a passenger aircraft. If you cannot understand changes in the aircraft business landscape, I don't know what to say.
    - zaarn 5y ago
      > (And, incidentally, airlines do not, in fact, train pilots for "all engines failed"; it is considered too unlikely and too unsurvivable.) Nope, that is wrong. Even before Sully, pilots are trained for All Engines Out. Aircraft even have systems to handle this like the RAT (Ram Air Turbine) which deploy on loss of power to enable critical systems like control surfaces and basic navigational gear (GPS, Radar, Artifical Horizon). Prop planes will feather all engines to maximize gliding distance. All Engines Out is definitely survivable and in some cases was even recoverable in flight. After Sully, the practise of training for All Engines Out was expanded to even lower altitudes and earlier in the takeoff procedure (as noone had failed all three engines that low before). You can read that in the FAA report (and the Mayday Episode summarizing it). There is other episodes too, like cases where the aircraft ran out of fuel (Gimli Glider) or flew through Volcanic Ash (BAF 9).
      - ncmncm 5y ago
        My brother is an airline pilot. He is given exactly zero hours of simulator time for "All engines out". That flights have survived the event does not contradict the fact.
        zaarn 5y ago
        Well, probably ask your brother again, because All Engines Out is required for a pilots license in the US and most other countries. Even Helicopter pilots have to train in the simulator for engine failure (autorotation landing). It must come up in training atleast once and every aircraft has an "all engine failure" checklist for this exact situation (The FAA recommended the addition of a "all engine failure at low altitude" checklist as well, which I believe has occured). Either your brother is incorrect about the simulator requirement, forgot about it or is flying a two-seater Cessna. You can verify this also by watching some of the videos of popular pilots on youtube such as Mentour of 74Crew.

ncmncm 5y ago

> loss of all three computers isn’t inherently dangerous You seem to be using a different definition of "dangerous" from the rest of us. Loss of systems that pilots are used to depending on is inherently dangerous. After that, degrees of luck, skill, and conservative planning become major factors in the outcome. The loss of spoilers and reversers is itself dangerous. In slightly different conditions, e.g. snow, the aircraft would not have stopped where it did. There was a Lockheed aircraft that ran off the end of a runway at an above-usual touchdown speed: the spoilers would not go up because for lack of weight on wheels, and brakes had no traction because spoilers were not up.

avianlyric 5y ago
I don’t know what to say. Pilots are trained for this exact situation, flight plans are designed for this situation. Every reasonable measure is taken to ensure that this exact situation isn’t unnecessarily more dangerous than it absolutely needs to be. As proven by this exact incident. You can talk about hypotheticals like snow, but this is a commercial airport. They will either have snow clearing equipment or they’ll redirect planes if they can’t clear the snow. It’s also Taipei where it basically never snows around the city. Simply put if it was unsafe to land this plane in this state with snow (and snow was believed to fall that day), then the plane wouldn’t even take off. Lockheed aircraft aren’t passenger airlines, they have a completely different risk profile and risk appetite. I imagine Lockheed aircraft occasionally get taken down my enemy fire, but we don’t build commercial aircraft to handle that situation.
- ncmncm 5y ago
  "[Not] unnecessarily more dangerous" is very far from the same as "not dangerous". If you cannot imagine this identical failure occurring at a different airport, in different ground conditions, I don't know what to say. You might as well say Sully splashing down in the Hudson without loss of life was unsurprising because he was trained for emergencies. (And, incidentally, airlines do not, in fact, train pilots for "all engines failed"; it is considered too unlikely and too unsurvivable.) Lockheed did make many, many passenger aircraft, and the failure I cited was, in fact, in a passenger aircraft. If you cannot understand changes in the aircraft business landscape, I don't know what to say.
  - zaarn 5y ago
    > (And, incidentally, airlines do not, in fact, train pilots for "all engines failed"; it is considered too unlikely and too unsurvivable.) Nope, that is wrong. Even before Sully, pilots are trained for All Engines Out. Aircraft even have systems to handle this like the RAT (Ram Air Turbine) which deploy on loss of power to enable critical systems like control surfaces and basic navigational gear (GPS, Radar, Artifical Horizon). Prop planes will feather all engines to maximize gliding distance. All Engines Out is definitely survivable and in some cases was even recoverable in flight. After Sully, the practise of training for All Engines Out was expanded to even lower altitudes and earlier in the takeoff procedure (as noone had failed all three engines that low before). You can read that in the FAA report (and the Mayday Episode summarizing it). There is other episodes too, like cases where the aircraft ran out of fuel (Gimli Glider) or flew through Volcanic Ash (BAF 9).
    - ncmncm 5y ago
      My brother is an airline pilot. He is given exactly zero hours of simulator time for "All engines out". That flights have survived the event does not contradict the fact.
      - zaarn 5y ago
        Well, probably ask your brother again, because All Engines Out is required for a pilots license in the US and most other countries. Even Helicopter pilots have to train in the simulator for engine failure (autorotation landing). It must come up in training atleast once and every aircraft has an "all engine failure" checklist for this exact situation (The FAA recommended the addition of a "all engine failure at low altitude" checklist as well, which I believe has occured). Either your brother is incorrect about the simulator requirement, forgot about it or is flying a two-seater Cessna. You can verify this also by watching some of the videos of popular pilots on youtube such as Mentour of 74Crew.