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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 tr
by 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 agoI 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 agoIt 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 agoActually, 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.
- inglor_cz 3y ago"Actually, sitting in front of tv is pretty safe." For injuries, yes. For general health, no. Sedentary lifestyle is a silent killer.
- notahacker 3y agoThe "this flight has significantly more risk of accident but it gets to your destination an hour earlier than a regular flight without a refuel stop" tradeoff isn't obviously one a significant proportion of consumers will take though, especially not at prices geared towards the "very important" set And even if they were willing to, it's entirely possible regulators wouldn't let them
- svnt 3y agoThese analyses always seem incomplete to me. You need a whole second plane, and that plane needs to take off and land, and carry and elevate significant extra fuel during its takeoff. I feel like the fuel economy savings are probably technically there because of the different aircraft characteristics, but again, you need to circuit an entire second plane and crew to “save” that fuel. I’m sure someone’s done the analysis.
- hef19898 3y agoPlus, you can fly non-stop half way, and then some, across the globe in existing planes today. More range ain't needed. Supersonic civilian aircraft are dead for a reason.
- krisoft 3y agoBut my understanding is that the Concorde was inneficient during takeoff because it was flying slower than the optimal speed dictated by its airframe and engines. Are you proposing to refuel it at cruise speed? If not, one would think that the refueling would use up a lot of fuel in itself.
- jdiez17 3y agoIt was inefficient at takeoff because it was using afterburners to get the thrust needed.
- SonicScrub 3y agoWhich was required due the huge amounts of aerodynamic drag produced by aircraft designed for supersonic flight while flying subsonic. These design are very aerodynamically inefficient outside their cruise speeds, and thus require a lot of thrust. This phase of flight extends all the way from take-off, and climb out. Not just while barreling down the runway. Having an extended subsonic flight period to do a mid-air refuelling would be brutal to the financial viability of a supersonic passenger aircraft. And that's even before we consider the operational costs of the tanker aircraft