Narrative:

Incident report: during level cruise at 1500' AGL, upon switching to left tank, the engine quit. Restart procedures were ineffective. Landed in hay field, no damage. Restart successful, took off on road. Cause: 1 week prior to flight, engine driven fuel pump began leaking. Left tank selector on, left tank emptied overnight. Upon replacing pump, 10 gals per side were put on board. Engine run on right tank was successful after fuel lines were purged (this model has no 'both' selection). Flight to other airport on right tank 20 mins long. Upon takeoff and reaching 1500', pilot switched to left tank. Air in line between reservoir and selector flowed into fuel pump causing vapor lock. With insufficient altitude to purge the lines, the forced landing was made. Attempts to restart on both right and left tank were unsuccessful. Preventive measures: properly flush or bleed fuel system after fuel system has been drained to prevent air anywhere in system. Pilot should run engine on both tank systems on ground until stable engine conditions are attained on both tank selections.

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Original NASA ASRS Text

Title: SMA HAS ENGINE FAILURE WHEN SWITCHING TANKS. EMERGENCY LNDG.

Narrative: INCIDENT RPT: DURING LEVEL CRUISE AT 1500' AGL, UPON SWITCHING TO LEFT TANK, THE ENG QUIT. RESTART PROCS WERE INEFFECTIVE. LANDED IN HAY FIELD, NO DAMAGE. RESTART SUCCESSFUL, TOOK OFF ON ROAD. CAUSE: 1 WK PRIOR TO FLT, ENG DRIVEN FUEL PUMP BEGAN LEAKING. LEFT TANK SELECTOR ON, LEFT TANK EMPTIED OVERNIGHT. UPON REPLACING PUMP, 10 GALS PER SIDE WERE PUT ON BOARD. ENG RUN ON RIGHT TANK WAS SUCCESSFUL AFTER FUEL LINES WERE PURGED (THIS MODEL HAS NO 'BOTH' SELECTION). FLT TO OTHER ARPT ON RIGHT TANK 20 MINS LONG. UPON TKOF AND REACHING 1500', PLT SWITCHED TO LEFT TANK. AIR IN LINE BTWN RESERVOIR AND SELECTOR FLOWED INTO FUEL PUMP CAUSING VAPOR LOCK. WITH INSUFFICIENT ALT TO PURGE THE LINES, THE FORCED LNDG WAS MADE. ATTEMPTS TO RESTART ON BOTH RIGHT AND LEFT TANK WERE UNSUCCESSFUL. PREVENTIVE MEASURES: PROPERLY FLUSH OR BLEED FUEL SYS AFTER FUEL SYS HAS BEEN DRAINED TO PREVENT AIR ANYWHERE IN SYS. PLT SHOULD RUN ENG ON BOTH TANK SYSTEMS ON GND UNTIL STABLE ENG CONDITIONS ARE ATTAINED ON BOTH TANK SELECTIONS.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.