A PLT OF A LIGHT SINGLE ENG ACFT EXPERIENCED ENG FAILURE BECAUSE OF FUEL STARVATION AS A RESULT OF AIR IN THE FUEL LINE.

Narrative

ENG FAILURE DUE TO FUEL STARVATION (MECHANICAL FAILURE). ON-ARPT ENG-OUT FORCED LNDG AT ZZZ RESULTED. NO DAMAGE. NO REPAIRS NEEDED. PREFLT PERFORMED POST-MAINT AT ZZZ1 SHOP RAMP. NORMAL PREFLT WAS PERFORMED; EXCEPT PLT WAS UNABLE TO REACH L TIP TANK FUEL SUMP DUE TO POS OF PLANE ON RAMP. PLT DID NOT NOTE FUEL AMOUNT IN TIP TANKS ON PREFLT; DUE TO FULL (35 GALLONS) MAIN TANK AND PLANNED 40 MIN FLT. AFTER NORMAL TKOF; A NORMAL CLBOUT FOR RETURN WAS PERFORMED. PLT NOTED R WING BEGAN TO FEEL 'HEAVY.' SUSPECTED AILERON TRIM TAB MAY HAVE BEEN BENT DOWN SLIGHTLY DURING MAINT; ALTHOUGH IT HAD APPEARED NORMAL DURING PREFLT. PLT THEN NOTED FUEL GAUGES INDICATED ALMOST FULL MAIN TANK (30 GALLONS); 20 GALLONS IN R TIP TANK; BUT 0 GALLONS INDICATED IN L TIP TANK (AUX TANK WAS EMPTY). TIP TANK GAUGES ARE ERRATIC AND NOTORIOUSLY INACCURATE; BUT AS A PRECAUTION; PLT ELECTED TO RETURN IMMEDIATELY TO HOME BASE DUE TO INCREASINGLY 'HVY' R WING. SHORTLY; THE ENG SURGED SLIGHTLY DURING CLBOUT. MIXTURE; PROP; AND PWR SETTINGS WERE NOTED TO BE NORMAL. ENG SURGED AGAIN APPROX 10 SECONDS LATER AND MANIFOLD PRESSURE DROPPED TO 20 INCHES FROM 26 INCHES. PLT ACTIVATED ELECTRIC BOOST PUMP; SUSPECTING ENG-DRIVEN FUEL PUMP FAILURE. ENG RECOVERED MOMENTARILY TO 36 INCHES MANIFOLD PRESSURE; THEN WENT TO IDLE 2-3 SECONDS LATER FOR APPROX 5 SECONDS. ENG THEN RECOVERED TO APPROX 20 DEGS MANIFOLD PRESSURE (AS DESIRED) FOR APPROX 30 SECONDS. BY THEN ACFT WAS DOWN TO 1100 FT MSL AND APPROX 140 KIAS; BUT ONLY APPROX 2 MI W OF ZZZ. ENG FAILED COMPLETELY 10 SECONDS LATER. PLT DECLARED EMER; LOWERED GEAR; FLAPS AND LANDED UNEVENTFULLY. AIRSPD AND ALT WERE SUFFICIENT TO LAND SAFELY; BUT INSUFFICIENT TIME TO CYCLE FUEL TANKS; ATTEMPT ENG RESTART OR EVEN SQUAWK 7700. ON POSTFLT INSPECTION; FUEL SELECTOR WAS STILL ON MAIN (VERIFIED APPROX 30 GALLONS REMAINING); L TIP TANK WAS VERIFIED AT 0; R TIP TANK WAS STILL APPROX 20 GALLONS. L TIP TANK SUMP VALVE WAS FOUND SLIGHTLY AJAR. L TIP TANK SUMP VALVE WAS RE-SEATED (VERIFIED BY A&P); TIP TANK WAS FILLED; BOOST PUMP RE-PRIMED AND ENG STARTED IMMEDIATELY AND GND RUN FOR 15-20 MINS UNEVENTFULLY. CONCLUSION: COMBINATION OF 25% PLT ERROR (FAILED TO VERIFY FUEL IN ALL TANKS BEFORE FLT; FAILED TO VERIFY TIP TANK SUMP VALVE FULLY SEATED BY WETNESS TEST; FAILED TO CORRECTLY IDENT AND ATTEMPT TO ADJUST FOR FUEL LOSS INFLT; ALTHOUGH POSSIBLY IRRELEVANT DUE TO NATURE OF THE MECHANICAL VALVE FAILURE). 5% MAINT ERROR (FAILED TO NOTE FUEL LEAKING OVER 2 DAYS; PARKED ACFT IN AWKWARD POS FOR THOROUGH PREFLT TO BE PERFORMED). 70% MECHANICAL FAILURE.