John, funny you should mention me!
If you look at the LCN charts, the C-5 is pretty light on its 28 paws. It was designed to fly a radar low-level, land a tank on a dirt runway and recover to FRA out of a CAT III autoland. Exactly how it was going to land, CAT III on the dirt was never explained. I, in a fit of "I don't give a crap" attitude familiar to all ex-mil types, didn't keep a perf manual. It was almost larger than the Flight Manual. But I still have friends, if I ever get off this never-ending trip.
Anyway, TOGW, runway permitting, was 769,000 pounds. Fuel burn of about 28,000 the first hour, 24,000 for the next 4, then gradually back to 20,000 at TOD. Average about 22,000 pph over 8-10 hours. Initial level, between 280 and 310 after near TOGW take-off, step up to 350-380, 9 hours later. Temp deviation was always an important factor.
172,000 pounds of thrust for 5 minutes. Rotate was about 138 knots at 769 and V2 would be around 150-154, as I remember. But acceleration was nothing to rave about check speed at 120 knots would be around 36-40 seconds and take-off roll at Torrejon could be close to a minute and 11,500 of 4-engine run. Most take-offs were closer to 6000-7500 feet, climb limited. At Ramstein with 8600 feet and 200 ft/nm required climb gradient, gross weights of about 735,000 to 750,000 were possible in all but the hottest days-380,000 lbs BOW, 120,000 pounds payload and 225,000-240,000 pounds of fuel for destination KDOV in 9 hours. 240,000 pound payloads necessarily required lots of tech stops or air refueling, not frequent ly done. But the USN seemed to design things to max it out. Dry runway Vmcg, a Pprune fave discussion, was about 80 knots without a crosswind. It was calculated for each take-off, adjusted for wind and runway condition. One of the more remarkable numbers! CF6-80A engines will improve things by reducing required fuel loads by 15%, faster climbs to levels that will optimize the wing.
Is any of this useful?
GF
John, Is Avalon on for next year?
Last edited by galaxy flyer; 22nd July 2008 at 02:29.