5 ms·

I have been trying to go over how this could happen. The damage to the wall seems so severe that I would image even over the sound of the engine the pilot would

by 14 8y ago

I have been trying to go over how this could happen. The damage to the wall seems so severe that I would image even over the sound of the engine the pilot would hear and notice that they had hit a wall. Flying the plane at this point would be risking their life. The first thing that came to my mind was the only reason a pilot would risk his life is if his life was already at risk and if he had been drinking when he hit the wall he would face many year in jail I assume for putting lives at risk. In a panic says to himself the plane is damaged but I know it can still fly and takes off without a plan really but perhaps just to let the alcohol he had leave his system. I hate to speculate here on HN. This is just crazy to me and I really look forward to hearing more details as to how his happened.

codeisawesome 8y ago
How will the alcohol ‘leave his system’ in the 4 hours it takes to fly to Dubai from India?
- ehnto 8y ago
  Pilots would have to blow 0.0 but that doesn't mean zero evidence of alcohol. In 4 hours you can metabolise around 4 standard drinks out of your bloodstream. It's not like drugs where any trace is bad because it's illegal. That said, I'm not sure I am on board with the explanation. It could just be that with everything going on in a cockpit it wasn't noticed.
  - Scoundreller 8y ago
    Does reduced air pressure speed up the removal of alcohol via breathing? If a fever can, wouldn’t alcohol do the same?
    - bcOpus 8y ago
      A fever is, at it’s core, an increase in metabolic rate. Your hypothalamus is telling your body that it’s temperature set point is higher than usual, and it takes energy to raise your temperature. I don’t see how a difference in air pressure would have a similar effect.
    - mediawatcher234 8y ago
      other way around - reduced air pressure is reduced oxygen, which is lower metabolism. Higher metabolism causes EtOH degradation to go more quickly. Fever is higher metabolism.
      - Scoundreller 8y ago
        Your blood oxygenation will stay at 95-99% even while in a cabin. Metabolism in aircraft is pretty low: you’re generally sitting idle, but I think the alcohol metabolism is still constant except the terminal metabolism. Fever is partly metabolism, but largely reduced cooling.
        agurk 8y ago
        I've taken an oximeter with me on flights before, and can give a data point of n=1 to say this isn't the case. My oxygen % decreased initially with altitude until it stabilised around 90-92% (at ~10k feet, IIRC). It sat at this point for the whole flight (8 hours), with a low of 87%. Through forced rapid deep breaths I could get it back up into the mid-high 90s, but also got light headed and funny looks. Moving around the cabin would also raise it.
        Scoundreller 8y ago
        Interesting, the studies i’ve Read pegged the average reduction at 4%.
captain_perl 8y ago
After V1, the accelerate-stop distance, the pilot is committed to continue flying. The cargo area of most airliners is not pressurized, so the gash is not an immediate problem. In a case like this, the pilots would want to climb to several thousand feet and evaluate the situation before landing. Looks like the pilot did a great job once it was realized the airplane was damaged of remaining calm and flying the airplane.
- lavrov 8y ago
  Not a pilot, and not trying to be an armchair pilot, but why would he have ascended all the way to 36000 feet? Isn't there a real risk of depressurization with hull damage?
  - sandworm101 8y ago
    No. If there was a leak then it wouldnt pressurize properly on the way up. If it was holding pressure, it would probably keep doing so.
    - spectre256 8y ago
      It totally depends. A weakened structure can hold pressurization for a while, and then suddenly (and possibly catastrophically) fail. A famous example of this is American Airlines flight 96 (1972): https://en.wikipedia.org/wiki/American_Airlines_Flight_96 https://en.wikipedia.org/wiki/American_Airlines_Flight_96
      - jedmeyers 8y ago
        Also Japan Airlines Flight 123
    - Johnny555 8y ago
      I'd rather not trust my life to "probably". If there was some damage to the hull or a cargo door that could lead to failure, it's under more stress and is more of a hazard as the altitude increases.
mmcconnell1618 8y ago
Over at http://pprune.org http://pprune.org the suggestion is that the pilot's seat was not locked into position correctly and slid back during takeoff. This caused the pilot to pull back on the stick too early and his instinct was the push forward to keep the plane on the correct trajectory. He likely over-corrected and ended up flying 6ft off the ground at the end of the runway where the landing gear caught an antenna and the chainlink fence on top of the brick wall. It's all speculation at this point.
- cjbprime 8y ago
  Ugh, there have been Cessna deaths caused the same way. It's my least favorite failure mode to think about, since there's no obvious way to correct. In a Cessna, best you can do is release the yoke and tiptoe on to the rudders, but professional instructors have still died when this happens to them, since low altitude errors are often not correctable by the time you've lost too much altitude. Usually there ought to be more than one locking mechanism involved, though..? https://generalaviationnews.com/2018/03/16/failure-secure-seat-fatal/ https://generalaviationnews.com/2018/03/16/failure-secure-se... https://generalaviationnews.com/2016/10/18/seat-sliding-backwards-on-takeoff-contributes-to-crash/ https://generalaviationnews.com/2016/10/18/seat-sliding-back...
  - userbinator 8y ago
    In contrast, I can't say I've ever heard of seats in cars having this problem. Is it because plane seats are highly optimised for weight?
    - cjbprime 8y ago
      Could be because people don't generally drive 40 year old cars! The aircraft in the first fatal link above was manufactured in 1979 and the seat failed in 2016; the second was manufactured in 1969 and crashed in 2014. And because it would be less likely fatal in the car, so you'd be less likely to hear of it happening. (Less likely fatal because car collisions are less fatal due to e.g. airbags, and less likely to impact terrain since it only takes a second to undo your car seatbelt, and because there's no pitch control to have messed up.)

by 14 8y ago

codeisawesome 8y ago

How will the alcohol ‘leave his system’ in the 4 hours it takes to fly to Dubai from India?

ehnto 8y ago
Pilots would have to blow 0.0 but that doesn't mean zero evidence of alcohol. In 4 hours you can metabolise around 4 standard drinks out of your bloodstream. It's not like drugs where any trace is bad because it's illegal. That said, I'm not sure I am on board with the explanation. It could just be that with everything going on in a cockpit it wasn't noticed.
- Scoundreller 8y ago
  Does reduced air pressure speed up the removal of alcohol via breathing? If a fever can, wouldn’t alcohol do the same?
  - bcOpus 8y ago
    A fever is, at it’s core, an increase in metabolic rate. Your hypothalamus is telling your body that it’s temperature set point is higher than usual, and it takes energy to raise your temperature. I don’t see how a difference in air pressure would have a similar effect.
  - mediawatcher234 8y ago
    other way around - reduced air pressure is reduced oxygen, which is lower metabolism. Higher metabolism causes EtOH degradation to go more quickly. Fever is higher metabolism.
    - Scoundreller 8y ago
      Your blood oxygenation will stay at 95-99% even while in a cabin. Metabolism in aircraft is pretty low: you’re generally sitting idle, but I think the alcohol metabolism is still constant except the terminal metabolism. Fever is partly metabolism, but largely reduced cooling.
      - agurk 8y ago
        I've taken an oximeter with me on flights before, and can give a data point of n=1 to say this isn't the case. My oxygen % decreased initially with altitude until it stabilised around 90-92% (at ~10k feet, IIRC). It sat at this point for the whole flight (8 hours), with a low of 87%. Through forced rapid deep breaths I could get it back up into the mid-high 90s, but also got light headed and funny looks. Moving around the cabin would also raise it.
        Scoundreller 8y ago
        Interesting, the studies i’ve Read pegged the average reduction at 4%.

captain_perl 8y ago

After V1, the accelerate-stop distance, the pilot is committed to continue flying. The cargo area of most airliners is not pressurized, so the gash is not an immediate problem. In a case like this, the pilots would want to climb to several thousand feet and evaluate the situation before landing. Looks like the pilot did a great job once it was realized the airplane was damaged of remaining calm and flying the airplane.

lavrov 8y ago
Not a pilot, and not trying to be an armchair pilot, but why would he have ascended all the way to 36000 feet? Isn't there a real risk of depressurization with hull damage?
- sandworm101 8y ago
  No. If there was a leak then it wouldnt pressurize properly on the way up. If it was holding pressure, it would probably keep doing so.
  - spectre256 8y ago
    It totally depends. A weakened structure can hold pressurization for a while, and then suddenly (and possibly catastrophically) fail. A famous example of this is American Airlines flight 96 (1972): https://en.wikipedia.org/wiki/American_Airlines_Flight_96 https://en.wikipedia.org/wiki/American_Airlines_Flight_96
    - jedmeyers 8y ago
      Also Japan Airlines Flight 123
  - Johnny555 8y ago
    I'd rather not trust my life to "probably". If there was some damage to the hull or a cargo door that could lead to failure, it's under more stress and is more of a hazard as the altitude increases.

mmcconnell1618 8y ago

Over at http://pprune.org http://pprune.org the suggestion is that the pilot's seat was not locked into position correctly and slid back during takeoff. This caused the pilot to pull back on the stick too early and his instinct was the push forward to keep the plane on the correct trajectory. He likely over-corrected and ended up flying 6ft off the ground at the end of the runway where the landing gear caught an antenna and the chainlink fence on top of the brick wall. It's all speculation at this point.

cjbprime 8y ago
Ugh, there have been Cessna deaths caused the same way. It's my least favorite failure mode to think about, since there's no obvious way to correct. In a Cessna, best you can do is release the yoke and tiptoe on to the rudders, but professional instructors have still died when this happens to them, since low altitude errors are often not correctable by the time you've lost too much altitude. Usually there ought to be more than one locking mechanism involved, though..? https://generalaviationnews.com/2018/03/16/failure-secure-seat-fatal/ https://generalaviationnews.com/2018/03/16/failure-secure-se... https://generalaviationnews.com/2016/10/18/seat-sliding-backwards-on-takeoff-contributes-to-crash/ https://generalaviationnews.com/2016/10/18/seat-sliding-back...
- userbinator 8y ago
  In contrast, I can't say I've ever heard of seats in cars having this problem. Is it because plane seats are highly optimised for weight?
  - cjbprime 8y ago
    Could be because people don't generally drive 40 year old cars! The aircraft in the first fatal link above was manufactured in 1979 and the seat failed in 2016; the second was manufactured in 1969 and crashed in 2014. And because it would be less likely fatal in the car, so you'd be less likely to hear of it happening. (Less likely fatal because car collisions are less fatal due to e.g. airbags, and less likely to impact terrain since it only takes a second to undo your car seatbelt, and because there's no pitch control to have messed up.)