The DC8 50 series w/ our new stage three hush kit burns about 15,500 PPH at 280,000 Pounds at 29000 ft and mach .72 in cruise. Does anyone know the fuel burn for a 757 which is of similar size. I would be very interested to know.
By the way I'm guessing with the 757 at 35000 ft at mach.77 It would burn about half of that. From MIA to Guatemala we burn about 45000 pounds. I bet a 757 would burn about 23000. Is there a pilot here who might fly that route with other equiptment.
A 757 at M.82 at that weight would really be sucking gas. Normal cruising speed is M.80 at altitude. A general fugure for that plane is between 7,500 pph and 8,000 pph depending on weight.
I've got a few pages from the 767-200 manual, which gives the fuel burn in NAM for a given TAS at altitude. Calculated out, book burn rates at 29,000 at Mach .80 are 10,500pph at 220,000 lb (very light) and 11,800pph at 310,000 lb (heavy).