APU Fuel burn/hour A320, 757, 767

[Fargoo]

Just a call for help from our pilot colleagues.
I'm currently trying to put a business case together for some permanent ground power support on some currently unpowered remote stands at LHR.
We are at the moment supposed to use GPU's (diesel powered) but these are always nicked by the terminals and never returned. Consequently we generally use the APU's for overnight maintenance on these stands.
If I can put a proper business case together with savings (both cash and environmental) it might kick the right bums into action.

I know you boys and girls generally encounter long delays where extended use of the APU will be needed. Can you give me some real world consumption figures for the aircraft you fly (kg/hour).

I'm only after A319.320.321 or B757.767 as these are the types we operate on these stands.

Thanks very much in advance. :)

[Preppy]

APU fuel consumption data is readily available from onboard manuals - much depends on whether the a/c packs are in use or not. What is more difficult to ascertain is the hourly fixed (overhaul) costs of an APU.
Actually none of this really matters in the UK, as all airports are subject to CAP 642:
APUs are not to be used as a substitute for either FEGP or GPUs. and Airlines and handlers are to ensure that APUs are used for the absolute minimum time
necessary to meet operational needs.
Heathrow Airport bye laws reflect this guidance material.
Back to the drawing board? :)

[XPMorten]

Have a 757 manual that says;

APU (airborn) 200 lb/h
APU(ground) 235 lb/h

M

[Fargoo]

Thanks to both of you.

Preppy, unfortunately there are lots of regs and byelaws at LHR that aren't adhered to. What constitutes absolute minimum time to meet operational requirements for example? We very rarely get the yellow perils out as far as these stands as they're engineering stands and are only used for parking or maintenance.

[Canuckbirdstrike]

Fargoo:

I have done this type of analysis and business case many times. The easy elements to capture are the APU fuel consumption values. The tough ones to capture are the APU capital costs and maintenance costs.

However, as a guideline APU costs when compared to fixed GPU systems are from 6 (A320) to 25 (A340-500) times more expensive.

In addition to the fuel/operating cost portion of the business case the other issue is environmental pollution.

If you want to discuss further PM me.
Richard
Technical Pilot, Fuel & Operating Efficiency

[Bealzebub]

A320 2.17 kg/min 130kg/hr
A321 Same
B757 1.78kg/min 107kg/hr
B767 1.92kg/min 116kg/hr
A319 Don't know but probably same as A320

[None]

APU Cost to Operate
APU Burn Rate Cost Per Hour
Aircraft Gal/Min Fuel Maint. Fuel & Maint.
B757 0.82 $110.14 $25.42 $135.56
B767 ER 0.82 $96.97 $12.25 $109.22
B777 1.42 $212.85 $66.46 $279.31