AN ATX TWIN PLT LANDED IN A BEAN FIELD AT NIGHT AFTER FUEL EXHAUSTION.

Narrative

I DEPARTED 3HA BOUND FOR CMI AND SPI ON THE MORNING OF SEP/TUE/92 WITH A STANDARD LOAD OF FUEL (TOPPED INBOARDS; 20 GALLONS IN EACH OUT) 108.6 GALLONS. THIS SHOULD HAVE BEEN ENOUGH TO FLY THE MORNING RUN ON THE OUTBOARDS ONLY. HOWEVER; BOTH OUTBOARD TANKS RAN DRY PRIOR TO REACHING SPI. AS I PREFLTED THAT NIGHT; I NOTICED THE FUEL LEVELS IN THE R INBOARD LOOKED LOW; SO I HAD 5 GALLONS ADDED TO THAT TANK. I FLEW APPROX 15 MINS ON THE R AND 5 ON THE L. I DEPARTED SPI WITH WHAT I BELIEVED TO BE A LITTLE OVER 30 GALLONS IN EACH INBOARD. FLT TO DEC AND CMI WAS NORMAL; FLYING TIME APPROX 30 MIN. THAT SHOULD HAVE LEFT ABOUT 25 GALLONS IN EACH INBOARD; MORE THAN ENOUGH FOR THE 35 MIN FLT TO 3HA. ALL LOOKED NORMAL ON DEP AND I LEVELED OFF AT 5500 FT. AN IFR FLT PLAN WAS FILED BUT NOT ACTIVATED. N OF IKK; I NOTICED BOTH FUEL GAUGES READING ABNORMALLY LOW. A QUICK MENTAL CHK TOLD ME I SHOULD HAVE AT LEAST 15-20 GALLONS PER SIDE; SO I CONTINUED. MINS LATER; THE R ENG SPUTTERED FOLLOWED IN SHORT SUCCESSION BY THE L. I REQUESTED AND RECEIVED IMMEDIATE VECTORS TOWARD C56. WHEN I SAW I WAS TOO FAR TO MAKE C56; I LANDED GEAR UP IN A BEAN FIELD WITH LITTLE DAMAGE TO AIRPLANE. NO INJURIES TO MYSELF. THE FIRST RED FLAG WENT ON WHEN THE OUTBOARDS RAN DRY EARLIER THAN EXPECTED. THE NEXT RED FLAG WENT UP WHEN THE INBOARDS ON THE R SIDE LOOKED ABNORMALLY LOW. AT THAT POINT; I SHOULD HAVE TOPPED OFF BOTH INBOARDS. THAT WOULD HAVE GIVEN A FIXED; ABSOLUTE QUANTITY OF GAS. I ONLY PUT 5 GALLONS IN BECAUSE I WAS UNDER INSTRUCTIONS THAT ONLY NECESSARY FUEL BE ADDED AWAY FROM THE BASE. THEREFORE; AFTER LOOKING AT FLT TIMES; ESTIMATED FLT TIMES AND FUEL GAUGES; 5 GALLONS APPEARED THE ONLY NECESSARY FUEL. HAD THE WX BEEN POOR OR IMC; I WOULD HAVE DEFINITELY TOPPED THE INBOARDS. SECONDLY; AT THE FIRST HINT OF ABNORMAL FUEL LEVELS; I SHOULD HAVE IMMEDIATELY PLANNED TO LAND. I DID NOT BECAUSE; GIVEN FUEL INDICATIONS AT TKOF; THERE SHOULD HAVE BEEN PLENTY TO MAKE DEST. I ASSUMED BOTH GAUGES WERE GOING BAD AND MEANT TO HAVE MAINT LOOK THEM OVER. THE OLD AXIOM: TRUST THE GAUGES WAS NOT LISTENED TO. I COULDN'T COMPREHEND WHERE THE FUEL WENT.