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HS.748 Fuel Usage

Posted: 06 Jul 2006, 21:24
by Graeme
Hi All,

I've been doing some measurements of the 748 fuel burn, and thought I'd share it to assist with flight planning. Figures based on a MTOW departure, under ISA conditions.

Ground Idle: 600 lbs/h (272kg/h)
Taxi: 800 lbs/h (363kg/h)
Normal Startup & Taxi Allowance 250 lbs (113kg)

Sea Level Takeoff and 170kts IAS climb (14200rpm, 730tgt) to:
FL50: 220 lbs (100kg) - 5 minutes
FL100: 400 lbs (181kg) - 11 minutes
FL150: 600 lbs (272kg) - 18 minutes
Use next highest value in planning, ie for FL130, use FL 150 figures

Cruise (14200rpm, 730tgt) at:
FL50: 2150 lbs/h (975kg/h) - 210Kts IAS
FL100: 1900 lbs/h (862kg/h) - 200Kts IAS
FL150: 1450 lbs/h (658kg/h) - 190Kts IAS
Use next lowest value in planning, ie for FL130, use FL 100 figures

Decent to Sea Level at 180Kts IAS (11400rpm, full dec) from:
FL50: 70 lbs (32Kg) - 7 minutes
FL100: 130 lbs (59Kg) - 11 minutes
FL150: 180 lbs (82Kg) - 16 minutes
Use next highest value in planning, ie for FL130, use FL 150 figures

Approach & Reserves
10min Approach Config: 325 lbs (147 Kg)
45min Low Level Hold 180Kts IAS: 1315 lbs (596 Kg)
45min FL50 Diversion (Worse case): 1615 lbs (733 Kg)
Total Approach & Reserves: 3255lbs (1476Kg)

Hope this helps, if you find any figures vastly out please let me know, remember these figures are based on MTOW Takeoff so your actual burn should not exceed these figures at normal altitudes and temperatures.

Cheers,
--Graeme

Posted: 08 Jul 2006, 16:58
by Rick Piper
Hi Graeme

Yes very useful info.

Not too far from the real figures either to my surprize :worried: .

Regards
Rick :wink:

Posted: 22 Jul 2006, 22:59
by RAF_Quantum
Tks Graeme,

I've 'stickied' this to keep it near the top

Rgds

John