P-61 Endurance

[33k in the air]

230 mph don't look as max cruise, is possible that 91 was for each engine?

230 mph TAS was the most fuel-efficient cruise setting listed in the charts for 15,000 feet; there were no entries for higher altitudes in Column IV. The Maximum Range (Column V) section had no entries. Bumping the cruise speed up to 240 TAS at 15,000 feet consumed 180 gallons per hour (Column III); at 270 TAS, fuel consumption was 230 gallons per hour (Column II).

The important factor is that these are preliminary figures, and had yet to be flight checked. If anyone has a PFOI for the P-61 which has the flight-checked figures, then please do post the cruise figures from it.

 

[Vincenzo]

I've on the hard disk a 7/45 PFOI it report, for the max cruise, the 91 gph at 35.5 low gear 18k feet with the -10&-65 engine variant
idk if USAAF in this table for twin engined fighter report each engine consume or for both

 

[GregP]

You are correct. 60 to 91 gallons per hour per engine, depending on cruise power. So, that takes us to about 2.5 - 3.2 hours endurance, on internal fuel alone, assuming a 1/2 hour fuel reserve. Combat time significantly reduces that time.