AN EXPERIMENTAL EXPERIENCED FUEL EXHAUSTION AFTER A 25 YR OLD PLASTIC FUEL PUMP INLET CONNECTOR FAILED.

Narrative

AFTER NORMAL PREFLT; TAXI; TAKEOFF; AND CLB TO 1800 FT MSL; APPROX 8 MILES FROM ARPT ENGINE BEGAN TO LOSE PWR. ONLY SUITABLE FIELD WAS A MATURE SOYBEAN FIELD APPROX 3 FEET DEEP. AFTER QUICK EMER CHK OF FUEL AND ELECTRIC; PLT MADE LNDG IN SAID FIELD CAUSING DAMAGE TO PROPELLER AND LNDG GEAR. INCIDENT; AS DESCRIBED IN 49 CFR PART 830-5; EXEMPTS THIS BEING RPTED. REASON FOR THIS RPT IS IN INTEREST OF SAFETY; IN LIGHT OF THE FACT THAT APPROX 3000 KITS FOR THIS AIRPLANE WAS SOLD IN THE LATE 70'S AND 80'S OF WHICH APPROX 300 WERE COMPLETED. AFTER INCIDENT; INVESTIGATION REVEALED PROBABLE CAUSE OF POWER FAILURE WAS DUE TO FUEL EXHAUSTION -- CAUSED BY A FORM FITTING AT THE FUEL INLET PORT (FUEL PUMP BODY CONSTRUCTION WAS OF BAKELITE PLASTIC). THE FUEL PUMP WAS MOUNTED DIRECTLY TO THE CARBURETOR MADE OF CAST ALUMINUM BOTH OF WHICH WERE PAINTED GRAY. FITTING FAILURE CAUSED BY AGE AND VIBRATION (25 YEARS OLD AT BEST ESTIMATE; 230 HRS FLT TIME). FUEL PUMP FITTING WAS FOUND TO BE VERY BRITTLE. OTHERS IN THE FIELD ARE PROBABLY IN THE SAME CONDITION. THIS PUMP WAS INSTALLED ON A CONVERTED ONAN STATIONARY GENERATOR ENGINE. IN THE INTEREST OF SAFETY TO ANY LIGHT AIRPLANE FLOWN IN THE FALL; HARVEST TIME OF YEAR; A SAFETY CIRCULAR OR POSTER HIGHLIGHTING THE DIFFICULTY OF AN OFF ARPT LNDG; WOULD BE OF BENEFIT TO PLTS UNFAMILIAR WITH AGRICULTURAL CROPS (SOY BEANS 3 FT TALL STOP AN AIRPLANE IMMEDIATELY).