5 ms·

Well, loss of engine power and gliding to a stop is not that a far fetched case. Why is there not a fuel dump button to prevent a whole trips worth of fuel goin

Well, loss of engine power and gliding to a stop is not that a far fetched case. Why is there not a fuel dump button to prevent a whole trips worth of fuel going up in flames?

Mindwipe 1y ago
They were only 600ft in the air, barely anything would have got out before they hit the ground and you'd have just set non-zero amount of innocent people on fire in all likelihood when the crash ignited the trail they'd left. There is a dump fuel button if you're not in the middle of a populated city and you're far enough in the sky you've got a few minutes.
iamtheworstdev 1y ago
because painting an entire neighborhood in flammable fluid isn't safe... if it doesn't catch fire it'll corrode everything it touches. most planes can't dump fuel anymore. if it's a serious enough emergency you land overweight. If it's not then you fly long enough to burn it off and land below max landing weight.
- sofixa 1y ago
  > most planes can't dump fuel anymore. if it's a serious enough emergency you land overweight. When fuel is dumped, it's at high altitude where it just evaporates. Short haul jets can't do it, but their max takeoff weight is around their max landing weight, so it's fine. For long haul, it's not the same.
  - dspillett 1y ago
    It wouldn't have been in this case, is the point people are making.
  - krisoft 1y ago
    This airplane was not at high altitude. It crashed right after taking off. It only ever climbed to a few hundred feet in the air.
    - sofixa 1y ago
      Yes, I was refuting the generic "planes don't dump fuel" statement.
  - Larrikin 1y ago
    Are both opposing replies just wild speculation from two educated software engineers that don't actually know anything on the topic?
    - Symbiote 1y ago
      > most planes can't dump fuel anymore This is true but irrelevant to this crash. Most commercial jets are smaller (A320, 737 etc) and can't dump fuel. Long-haul jets like the 787 do have the capability. https://www.boeing.com/content/dam/boeing/boeingdotcom/commercial/airports/faqs/fueldump.pdf https://www.boeing.com/content/dam/boeing/boeingdotcom/comme...
    - Mistletoe 1y ago
      If it’s HN, yes always.
    - speakfreely 1y ago
      No one overestimates themselves in other knowledge domains quite like software engineers... with the possible exception of medical doctors.
- wkat4242 1y ago
  It won't corrode I don't think. It's just oil, it's not petrol like in small airplanes.
mdavidn 1y ago
There is, but dumping takes time, and it’s not done over populated areas. It would be low on the pilots’ checklist in an emergency.
- wkat4242 1y ago
  Yes and smaller airliners don't have it. As I understand it, it's for the widebodies because they often have a higher maximum takeoff weight than maximum landing weight. Meaning that if they just took off and need to return right away they have a big problem. Because they're too heavy to land.
ekianjo 1y ago
It's possible to dump fuel but you don't have time to dump enough in an emergency
detaro 1y ago
Most airplanes can dump fuel, but it's not an immediate thing, so not really applicable here (and obviously doing it over a city is to be avoided as well). It's primarily needed for weight management in planes that can take off heavier than they can safely land. I.e. if the plane had enough control to abort the flight and return to the airport, then it might have been appropriate.
- buildsjets 1y ago
  No. Most airliners CANNOT dump fuel. This capability is limited to long range wide bodies, like this 787. Neither the 737 nor the A320, which constitute the majority of commercial air traffic, can dump fuel. Fuel dumping is normally performed at an altitude where it should be able to evaporate before hitting the ground, and it takes a long time, maybe 15 minutes to get from full fuel to maximum landing weight. Using it would have made no difference to the outcome of the flight other than making a larger fire on the ground.
  - randomNumber7 1y ago
    A more dispersed fire. The amount of fuel isn't changed by dumping.
    - buildsjets 1y ago
      No. I said a larger fire, and I meant it. The fuel on the aircraft is not the only thing feeding the post-crash fire. Dousing the entire flight path with an accelerant would have resulted in many many buildings being on fire, instead of just a few of them.
  - AnimalMuppet 1y ago
    Didn't Sully dump fuel before landing in the Hudson, thereby increasing the buoyancy of the plane?
    - thecosmicfrog 1y ago
      No, the Airbus A320 cannot dump fuel.

Well, loss of engine power and gliding to a stop is not that a far fetched case. Why is there not a fuel dump button to prevent a whole trips worth of fuel going up in flames?

Mindwipe 1y ago

They were only 600ft in the air, barely anything would have got out before they hit the ground and you'd have just set non-zero amount of innocent people on fire in all likelihood when the crash ignited the trail they'd left. There is a dump fuel button if you're not in the middle of a populated city and you're far enough in the sky you've got a few minutes.

iamtheworstdev 1y ago

because painting an entire neighborhood in flammable fluid isn't safe... if it doesn't catch fire it'll corrode everything it touches. most planes can't dump fuel anymore. if it's a serious enough emergency you land overweight. If it's not then you fly long enough to burn it off and land below max landing weight.

sofixa 1y ago
> most planes can't dump fuel anymore. if it's a serious enough emergency you land overweight. When fuel is dumped, it's at high altitude where it just evaporates. Short haul jets can't do it, but their max takeoff weight is around their max landing weight, so it's fine. For long haul, it's not the same.
- dspillett 1y ago
  It wouldn't have been in this case, is the point people are making.
- krisoft 1y ago
  This airplane was not at high altitude. It crashed right after taking off. It only ever climbed to a few hundred feet in the air.
  - sofixa 1y ago
    Yes, I was refuting the generic "planes don't dump fuel" statement.
- Larrikin 1y ago
  Are both opposing replies just wild speculation from two educated software engineers that don't actually know anything on the topic?
  - Symbiote 1y ago
    > most planes can't dump fuel anymore This is true but irrelevant to this crash. Most commercial jets are smaller (A320, 737 etc) and can't dump fuel. Long-haul jets like the 787 do have the capability. https://www.boeing.com/content/dam/boeing/boeingdotcom/commercial/airports/faqs/fueldump.pdf https://www.boeing.com/content/dam/boeing/boeingdotcom/comme...
  - Mistletoe 1y ago
    If it’s HN, yes always.
  - speakfreely 1y ago
    No one overestimates themselves in other knowledge domains quite like software engineers... with the possible exception of medical doctors.
wkat4242 1y ago
It won't corrode I don't think. It's just oil, it's not petrol like in small airplanes.

mdavidn 1y ago

There is, but dumping takes time, and it’s not done over populated areas. It would be low on the pilots’ checklist in an emergency.

wkat4242 1y ago
Yes and smaller airliners don't have it. As I understand it, it's for the widebodies because they often have a higher maximum takeoff weight than maximum landing weight. Meaning that if they just took off and need to return right away they have a big problem. Because they're too heavy to land.

ekianjo 1y ago

It's possible to dump fuel but you don't have time to dump enough in an emergency

detaro 1y ago

Most airplanes can dump fuel, but it's not an immediate thing, so not really applicable here (and obviously doing it over a city is to be avoided as well). It's primarily needed for weight management in planes that can take off heavier than they can safely land. I.e. if the plane had enough control to abort the flight and return to the airport, then it might have been appropriate.

buildsjets 1y ago
No. Most airliners CANNOT dump fuel. This capability is limited to long range wide bodies, like this 787. Neither the 737 nor the A320, which constitute the majority of commercial air traffic, can dump fuel. Fuel dumping is normally performed at an altitude where it should be able to evaporate before hitting the ground, and it takes a long time, maybe 15 minutes to get from full fuel to maximum landing weight. Using it would have made no difference to the outcome of the flight other than making a larger fire on the ground.
- randomNumber7 1y ago
  A more dispersed fire. The amount of fuel isn't changed by dumping.
  - buildsjets 1y ago
    No. I said a larger fire, and I meant it. The fuel on the aircraft is not the only thing feeding the post-crash fire. Dousing the entire flight path with an accelerant would have resulted in many many buildings being on fire, instead of just a few of them.
- AnimalMuppet 1y ago
  Didn't Sully dump fuel before landing in the Hudson, thereby increasing the buoyancy of the plane?
  - thecosmicfrog 1y ago
    No, the Airbus A320 cannot dump fuel.