RPTR RAN HELI OUT OF FUEL.

Narrative

ON AN INST TRAINING FLT FROM 48V TO FNL AND RETURN IN PISTON HELI; WE EXPERIENCED AN ENG FAILURE DURING HOVER. IT WAS DETERMINED THAT THE ENG QUIT DUE TO FUEL STARVATION. DURING PREFLT I CHKED THE FUEL TANKS WITH A DIPSTICK AND DETERMINED THAT THERE WAS 28 GALLONS AND RETURNED THE DIPSTICK TO ANOTHER HELI. ON THE RETURN FLT; WE BECAME CONCERNED WITH THE FUEL LEVEL. ACCORDING TO THE HELI OPERATOR IT BURNS 12.4 GALLONS PER HR. ON THIS POINT HE IS ADAMANT. USING THAT FIGURE WE DETERMINED THAT WE SHOULD HAVE 1.8 HRS FLT TIME WITH RESERVES. AFTER ONLY 1.3 HRS; THE FUEL LEVEL WAS INDICATING UNDER 30 LBS. WE DECIDED TO MAKE A PRECAUTIONARY LNDG AT AN ARPT COMMUNITY. WE WERE ABLE TO LOCATE A RESIDENT; WHO CAME OUT AND TURNED ON THE 100 LOW LEAD FUEL PUMP. THE PUMP WAS OF THE TYPE WHERE ALL THE NUMBERS ARE WHITE ON BLACK WITH NO DECIMAL POINT. I ASKED IF THE PUMP READ IN TENTHS OR GALLONS AND HE REPLIED GALLONS. BEING AS BOTH PLTS ARE USE TO HIGH CAPACITY FUEL PUMPS USED IN TURBINE OPS; WE DID NOT FIND THIS CURIOUS. I DISPENSED 12 GALLONS AND WE SECURED THE PUMP AND DEPARTED. IT WAS LATER DETERMINED THAT THE PUMP READS IN TENTHS AND THAT WE HAD ONLY TAKEN 1.2 GALLONS DURING REFUELING. DURING POST MAINT CHK FLTS IT WAS ALSO DETERMINED THAT THE HELI WAS BURNING 16 GALLONS PER HR AND NOT 12.4 GALLONS PER HR AS WAS PREVIOUSLY RPTED. CONTRIBUTING FACTORS WERE: TURBINE PLTS USE TO HIGH CAPACITY FUEL SYS; FAILURE TO VERIFY FUEL DELIVERED WITH A DIPSTICK AND ERRONEOUS FUEL CONSUMPTION CALCULATIONS. THE CORRECTIVE ACTION HAS BEEN TO OBTAIN AND CARRY A FUEL DIPSTICK AND CALCULATE FLT TIMES BASED ON 16 GALLONS PER HR.