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kb 13th March 2011 21:41

P51 fuel consumption & "fighting weight" on long range escort
 
Looking for some understanding of the fuel consumption of a P51 on the inbound leg of a deep penetration escort (ie, Berlin)?

Assuming an uneventful flight inbound, what would the fuel state typically be upon arrival in the target area?

Would fuselage tank be emptied by that point?

Kutscha 13th March 2011 22:59

Re: P51 fuel consumption & "fighting weight" on long range escort
 
Fuel in the fuselage tank would be burned off to about 1/3 full. Then a switch to the drop tanks would take place. The a/c would have full wing tanks, 1/3 fuselage tank and what ever was left in the drop tanks.

kb 14th March 2011 03:00

Re: P51 fuel consumption & "fighting weight" on long range escort
 
Thanks for the quick reply. Any idea of the weight difference with the fuselage tank down to 1/3 full?

Revi16 14th March 2011 13:05

Re: P51 fuel consumption & "fighting weight" on long range escort
 
Quote:

Originally Posted by kb (Post 124341)
Thanks for the quick reply. Any idea of the weight difference with the fuselage tank down to 1/3 full?

The fuselage tank was 85 US gallons and gasoline weighs approx. 6.5lbs per gallon.
Full tank - 552lbs
1/3 Full - 184lbs.

drgondog 14th March 2011 23:30

Re: P51 fuel consumption & "fighting weight" on long range escort
 
http://www.wwiiaircraftperformance.o...51d-15342.html

This is the best report you will ever see on cruise performance with external stores, rpm, GW, Hg/boost, speeds, altitudes.

Basic stuff - 9760 pounds GW at take off with full load of ammo, 25 gallons in fuse tank, 184 gallons in main, 21 gallons of oil.

Add two 110 gallon drop tanks = 1490 pounds to get 11250 GW at take off with the loaded drop tanks.

Data at cruise altitude 25K = 281mph, 4.91 miles per gallon, 32 '' at 2250 rpm.

Use ~ 12 gallons for warm up and TO, then another 48-50 gallons to get to 25K over Dutch Coast. If you start with Max GW and 85 gallons, add another 60x5.87#/gallon of gasoline (~6.5 for JP5)-----> 11,600 pounds.

Would take about 2 hours to go straight to Berlin, but essing above bombers at 281mph only proceeds to Berlin at 150 mph IAS for B-17 at 25K (~180mph TAS) -----> maybe 2 hr 20 min from Dutch Coast?

at 4.91miles per gallon at 281mph -----> 57 gallons per hour.

Drop tanks at Berlin if there is a fight, say 25 gallons internally in fuse, plus 184 in mains - the bird would be close to 9700 pounds and 41.6#/sf WL.

Use the Brequet equations if you want more precision .. I haven't checked my math

Revi16 15th March 2011 01:52

Re: P51 fuel consumption & "fighting weight" on long range escort
 
The weight-density of gasoline is about 740 kg/m³ (6.175 lb/US gal; 7.416 lb/imp gal).

Bill Walker 15th March 2011 02:46

Re: P51 fuel consumption & "fighting weight" on long range escort
 
Just being picky, but ...

AvGas is less dense than automobile gasoline. for 100/130 octane today, 6.0 lbs per US gallon is a good number. 80/87 is only slightly heavier, say 6.1. I expect aviation fuel in WW2 was closer to 6.0.

drgondog 15th March 2011 14:03

Re: P51 fuel consumption & "fighting weight" on long range escort
 
Revi - according to my handy Hamilton Standard Aero Vest Pocket Handbook 110LL avgas is 5.87 pounds per gallon, JP1 is 6.65, JP6 is 6.759 and Kerosene is 6.7 pounds per gallon..and synthetic oil is 7.74

Berlin is 503 miles vis great circle course from London - the average from the fighter fields north of London was probably about the same.


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