# How far could a KC-10 tanker fly if it consumed all of its internal fuel tanks?

I have read that the KC-10 tanker aircraft carries a maximum load of 356,000 lbs of fuel. It also consumes the same fuel that it carries for refueling other aircraft. So naturally, I am wondering: If the KC-10 took off at max weight and flew continuously until forced to land, how long would it fly? How far would it have flown in that time?

I just want a ballpark figure but I don't know how to go about estimating one.

• If you find the fuel burn per hour at cruise of the KC-10 you could determine a rough estimate. Oct 14, 2021 at 0:52
• Welcome to Av.SE!
– Ralph J
Oct 14, 2021 at 2:46
• For a transport airplane like this, it's roughly 1/3 structural weight, 1/3 payload, and 1/3 fuel. For a tanker the payload is also fuel, so the total range is roughly double of its airliner cousin. Oct 14, 2021 at 18:16

Not too hard to work out an educated guesstimate.

The CF6-50 used in the KC-10 has a thrust specific fuel consumption of .375-ish lbs fuel/lb-thrust/hour. Takeoff thrust is in the range of 53000 lbs.

Cruise thrust can be anywhere from 25-35% of max takeoff thrust depending on how fast you want to go. Let's say 30%.

30% of 53000 = 15,900. X .375 = 5,962 lbs/hr per engine.

Times 3 engines = 17,887 lbs/hr total fuel burn.

With 356000 lbs on board, it works out to 19.9, we'll say 20ish hours absolute endurance. Deduct a little bit to account for takeoff and climb.

Say you're able to get it to around Mach .8, or 460 kt true at 35000 ft. That gives an absolute range of somewhere around 9000 nautical miles.

Allowing for my sloppy quick math and different power settings, and takeoff/climb burn, a good ballpark range would be somewhere between 8-10,000 nautical miles and somewhere around 17-23 hours in the air.

• Wikipedia claims a ferry range of 10,000 nautical miles, so there you go, math still works! Oct 14, 2021 at 2:52
• Cool! I'll bet that's by slowing it down to M.7 or something. Oct 14, 2021 at 4:09
• Ugh, that's a long time in the air!
– Ralph J
Oct 14, 2021 at 21:07
• The Canadair Argus, a Bristol Britannia with R3350 turbo compound radials, optimized for maritime patrol, had a patrol endurance of 29 hrs at normal cruise, and low 30s dialed back from that. The R3350TC had the specific fuel consumption of an automotive diesel. Oct 14, 2021 at 23:46