P51 fuel consumption & "fighting weight" on long range escort

[kb]

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]

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]

Thanks for the quick reply. Any idea of the weight difference with the fuselage tank down to 1/3 full?

[Revi16]

Originally Posted by kb

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]

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]

The weight-density of gasoline is about 740 kg/m³ (6.175 lb/US gal; 7.416 lb/imp gal).

[Bill Walker]

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]

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.