Flight Details
The pilot-in-command (PIC) departed with a full fuel load of 82 gallons approximately 1230 PST. The main fuel tank contained 46 gallons of fuel, with 2.9 gallons unusable, and the remaining fuel in external saddle tanks.
Engine Failure
About 2.25 hours after takeoff, at approximately 1445, the engine flamed out while the PIC was executing a zero airspeed pedal turn course reversal over high trees. The helicopter descended into the trees and subsequently impacted terrain.
The PIC reported that within moments before the flameout, he noted the fuel level had reached approximately 15 gallons in the main tank. He then turned on the auxiliary fuel tanks transfer switch. The time between turning on the transfer switch and the flameout was approximately 45 to 60 seconds.
Cruise fuel flow to the engine was reported at 17-20 gallons per hour, and takeoff power fuel flow was reported at 32 gallons per hour.
Post-Crash Examination
Post-crash examination revealed less than one gallon of fuel in the rotorcraft's main fuel tank. No fuel was found in the fuel line connecting the tank to the engine fuel nozzle, the engine-driven fuel pump filter, or the power turbine governor fuel filter. The aircraft's fuel gauge had no markings on the glass faceplate. No fuel leaks were found within the main fuel tank. A post-crash test run of the engine showed normal performance. No low fuel warning system was installed on the rotorcraft.