4 ms·

Why not use this technology for civilian aircraft? In particular, the envisioned supersonic Boom has too little range to be able to service enough routes to be

Why not use this technology for civilian aircraft? In particular, the envisioned supersonic Boom has too little range to be able to service enough routes to be profitable. With refueling the economics might change dramatically.

jpollock 3y ago
If it goes wrong, they crash and you lose two planes and several hundred people. https://www.youtube.com/watch?v=vbQ9LXZwJ78 https://www.youtube.com/watch?v=vbQ9LXZwJ78
- dylan604 3y ago
  This is a bit skewed though. If there was no mid-air refueling and the plane was lost, you still loose several hundred people and a plane, but wouldn't be out the second plane. The second plane is autonomous so no additional people are lost. It's really not making the stat of losing a passenger plane more consequential.
  - enigmurl 3y ago
    Presumably GP was implying that adding a second plane increases the chance of a crash, not claiming that it increases the conseuqences should it happen
  - krisoft 3y ago
    > It's really not making the stat of losing a passenger plane more consequential. It makes it more likely, not more consequential. You know how on the ground they sometimes tell you to not wear your safety belts while they refuel the plane? It is because every refueling has a risk of fire. An inflight refueling probably even more so. > The second plane is autonomous so no additional people are lost. Worth noting that in these experiments the tanker plane was not uncrewed. It is the act of connecting the hose which is automated here. (And they also tested with autonomous receiver planes.)
    - HPsquared 3y ago
      To be fair, spills or leaks during refuelling on land risks forming a pool of burning liquid around the aircraft. Aerial refuelling leaks would go overboard so probably not the same fire risk. It's more a risk of collision, I think.
      - krisoft 3y ago
        > Aerial refuelling leaks would go overboard That assumes it is not an internal leak of course. Where would the receiver probe be? Probably on the nose or on the forward section of the cabin roof and you have to pipe that back to the fuel tanks (mostly in or around the wings). If maintenance ever does a shoddy job on connecting those pipes the time you will realise it is when jet-a is firehosing out of the galley. Now obviously that involves maintenance problems and a bit of bad luck too, but that is not an unheard of combination.
HPsquared 3y ago
I don't think aerial refuelling could ever be described as "economical". Edit: Maybe if the alternative is building and maintaining an airbase for refuelling stops.
- credit_guy 3y ago
  Concorde burned by far the most fuel during takeoff: 450 liters per minute. Of course, once at cruising altitude, it needed to have enough fuel to finish the trip, which was about 60 tons. The empty mass of Concorde was 75 tons, plus passengers and cargo, let's say about 110-120 tons. Imagine now that instead of pushing from the ground 180 tons, you only push 120 tons and refuel once you get there. That means you burn one third less fuel during takeoff. Not only that, you can have smaller engines, which means lighter construction in general, so less weight, etc. It's a virtuous cycle. Aerial refueling, if it can be fully automated, and made routine, and supersafe, could be revolutionary for civilian aircraft.
  - ulfw 3y ago
    I am sorry but automated or not, I don't see how aerial refueling could ever be made as safe as on-ground refueling by just the nature of two moving planes in the air rather than sitting immovable on the ground with just a hose or hose/small tanker vehicle attached.
    - credit_guy 3y ago
      It will never be as safe. But we always accept various tradeoffs. Traveling in a car is less safe than sitting on the couch in front of the TV, yet people do it all the time.
      - okr 3y ago
        Actually, sitting in front of tv is pretty safe. Once you do other sports at home, like taking drugs or climbing a ladder, then it can compete with travelling in cars.
godelski 3y ago
Sure, but it's still hard and unsafe. Use military as a testing ground to develop the technology to a more mature status first and make it economical. Have patience. This isn't going to be a practical technology for commercial flights until it gets cheap and fueling can be done efficiently
deleted 3y ago
[deleted]

jpollock 3y ago

If it goes wrong, they crash and you lose two planes and several hundred people. https://www.youtube.com/watch?v=vbQ9LXZwJ78 https://www.youtube.com/watch?v=vbQ9LXZwJ78

dylan604 3y ago
This is a bit skewed though. If there was no mid-air refueling and the plane was lost, you still loose several hundred people and a plane, but wouldn't be out the second plane. The second plane is autonomous so no additional people are lost. It's really not making the stat of losing a passenger plane more consequential.
- enigmurl 3y ago
  Presumably GP was implying that adding a second plane increases the chance of a crash, not claiming that it increases the conseuqences should it happen
- krisoft 3y ago
  > It's really not making the stat of losing a passenger plane more consequential. It makes it more likely, not more consequential. You know how on the ground they sometimes tell you to not wear your safety belts while they refuel the plane? It is because every refueling has a risk of fire. An inflight refueling probably even more so. > The second plane is autonomous so no additional people are lost. Worth noting that in these experiments the tanker plane was not uncrewed. It is the act of connecting the hose which is automated here. (And they also tested with autonomous receiver planes.)
  - HPsquared 3y ago
    To be fair, spills or leaks during refuelling on land risks forming a pool of burning liquid around the aircraft. Aerial refuelling leaks would go overboard so probably not the same fire risk. It's more a risk of collision, I think.
    - krisoft 3y ago
      > Aerial refuelling leaks would go overboard That assumes it is not an internal leak of course. Where would the receiver probe be? Probably on the nose or on the forward section of the cabin roof and you have to pipe that back to the fuel tanks (mostly in or around the wings). If maintenance ever does a shoddy job on connecting those pipes the time you will realise it is when jet-a is firehosing out of the galley. Now obviously that involves maintenance problems and a bit of bad luck too, but that is not an unheard of combination.

HPsquared 3y ago

I don't think aerial refuelling could ever be described as "economical". Edit: Maybe if the alternative is building and maintaining an airbase for refuelling stops.

credit_guy 3y ago
Concorde burned by far the most fuel during takeoff: 450 liters per minute. Of course, once at cruising altitude, it needed to have enough fuel to finish the trip, which was about 60 tons. The empty mass of Concorde was 75 tons, plus passengers and cargo, let's say about 110-120 tons. Imagine now that instead of pushing from the ground 180 tons, you only push 120 tons and refuel once you get there. That means you burn one third less fuel during takeoff. Not only that, you can have smaller engines, which means lighter construction in general, so less weight, etc. It's a virtuous cycle. Aerial refueling, if it can be fully automated, and made routine, and supersafe, could be revolutionary for civilian aircraft.
- ulfw 3y ago
  I am sorry but automated or not, I don't see how aerial refueling could ever be made as safe as on-ground refueling by just the nature of two moving planes in the air rather than sitting immovable on the ground with just a hose or hose/small tanker vehicle attached.
  - credit_guy 3y ago
    It will never be as safe. But we always accept various tradeoffs. Traveling in a car is less safe than sitting on the couch in front of the TV, yet people do it all the time.
    - okr 3y ago
      Actually, sitting in front of tv is pretty safe. Once you do other sports at home, like taking drugs or climbing a ladder, then it can compete with travelling in cars.

godelski 3y ago

Sure, but it's still hard and unsafe. Use military as a testing ground to develop the technology to a more mature status first and make it economical. Have patience. This isn't going to be a practical technology for commercial flights until it gets cheap and fueling can be done efficiently

deleted 3y ago

[deleted]