Narrative:

The extra 300/left aircraft is equipped with discretely selectable wing and fuselage fuel tanks. Engine start; taxi; takeoff; and initial climb was done using fuselage fuel tank; which was full before departure. Approximately 5 mins after takeoff; I selected wing fuel tanks and operated on wing fuel for approximately 35 mins. When wing fuel was nearly exhausted; I selected fuselage tank to complete the flight. About 5 seconds after doing so; I noticed fuel flow indication climbing from 16 gph past 25; indicating that air; rather than fuel; was being drawn from the tank and that engine failure was imminent. I reselected wing fuel; turned on electric fuel boost pump and waited for the fuel flow to settle back to 16 gph. I then selected the fuselage tank again and saw the same behavior; though this time I let the engine quit. I reselected wing fuel and the engine restarted. I reduced power to low cruise; began a climb to increase the likelihood that I could glide to an airport; and adjusted the mixture to the minimum fuel flow. (During this climb I believe I entered the northernmost ring of the class B airspace.) my wingman; who was flying a similar airplane alongside me; remained clear of the class B and assisted me in locating usable nearby airports in case a power-off or precautionary landing was required. I selected ZZZ; approached it overhead at 6800 ft MSL and low power. During this period; I tried 4 more times to select the fuselage tank; but each time the engine quit; after it did so; I returned to the wing tank; at which time it restarted. I expected the engine to quit again at any moment due to wing fuel exhaustion. Once I was sure I could reach the runway power-off; I changed to unicom frequency and announced my intentions; including a statement that I had an emergency. Other aircraft approaching the airport gave way and I landed without further incident. After landing I sumped the gascolator and fuselage tanks but found no evidence of contaminated fuel. My mechanic arrived; we uncowled the airplane and disconnected the fuel source line from the servo. Each selected tank was able to source fuel into the injector; the fuel; captured in a container; appeared uncontaminated. I later contacted the us importer of the airplane; explained the circumstances; they are advising on how to investigate the problem. What would I have done differently? If I had time; I'd have contacted the TRACON and informed them of the situation; given that wing fuel exhaustion was imminent; though; my sole focus was getting the airplane safely on the ground; preferably at an airport. I'd also have set my transponder on 7700; which would have been useful for tracking purposes in case I needed to land off airport. My wingman however; had me in sight for the entirety of my descent and landing at ZZZ.callback conversation with reporter revealed the following information: an airworthiness directive exists for the fuel selector in this aircraft and it will be replaced before the next flight. The 'O' rings in this selector tend to deteriorate and cause leaks but have not been reported to cause flow problems. The reporter flew through light rain at near freezing temperatures; then climbed to below freezing temperatures and believes that tank vent icing may be the source of the problem.

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Original NASA ASRS Text

Title: EA300 PLT RPTS INABILITY TO FEED FUEL FROM FUSELAGE TANK CAUSING PRECAUTIONARY LANDING. RPTR SUSPECTS TANK VENT ICING MAY HAVE CONTRIBUTED TO THE INCIDENT.

Narrative: THE EXTRA 300/L ACFT IS EQUIPPED WITH DISCRETELY SELECTABLE WING AND FUSELAGE FUEL TANKS. ENGINE START; TAXI; TAKEOFF; AND INITIAL CLB WAS DONE USING FUSELAGE FUEL TANK; WHICH WAS FULL BEFORE DEP. APPROX 5 MINS AFTER TAKEOFF; I SELECTED WING FUEL TANKS AND OPERATED ON WING FUEL FOR APPROX 35 MINS. WHEN WING FUEL WAS NEARLY EXHAUSTED; I SELECTED FUSELAGE TANK TO COMPLETE THE FLT. ABOUT 5 SECONDS AFTER DOING SO; I NOTICED FUEL FLOW INDICATION CLBING FROM 16 GPH PAST 25; INDICATING THAT AIR; RATHER THAN FUEL; WAS BEING DRAWN FROM THE TANK AND THAT ENGINE FAILURE WAS IMMINENT. I RESELECTED WING FUEL; TURNED ON ELECTRIC FUEL BOOST PUMP AND WAITED FOR THE FUEL FLOW TO SETTLE BACK TO 16 GPH. I THEN SELECTED THE FUSELAGE TANK AGAIN AND SAW THE SAME BEHAVIOR; THOUGH THIS TIME I LET THE ENGINE QUIT. I RESELECTED WING FUEL AND THE ENGINE RESTARTED. I REDUCED POWER TO LOW CRUISE; BEGAN A CLB TO INCREASE THE LIKELIHOOD THAT I COULD GLIDE TO AN ARPT; AND ADJUSTED THE MIXTURE TO THE MINIMUM FUEL FLOW. (DURING THIS CLB I BELIEVE I ENTERED THE NORTHERNMOST RING OF THE CLASS B AIRSPACE.) MY WINGMAN; WHO WAS FLYING A SIMILAR AIRPLANE ALONGSIDE ME; REMAINED CLEAR OF THE CLASS B AND ASSISTED ME IN LOCATING USABLE NEARBY ARPTS IN CASE A POWER-OFF OR PRECAUTIONARY LNDG WAS REQUIRED. I SELECTED ZZZ; APCHED IT OVERHEAD AT 6800 FT MSL AND LOW POWER. DURING THIS PERIOD; I TRIED 4 MORE TIMES TO SELECT THE FUSELAGE TANK; BUT EACH TIME THE ENGINE QUIT; AFTER IT DID SO; I RETURNED TO THE WING TANK; AT WHICH TIME IT RESTARTED. I EXPECTED THE ENGINE TO QUIT AGAIN AT ANY MOMENT DUE TO WING FUEL EXHAUSTION. ONCE I WAS SURE I COULD REACH THE RWY POWER-OFF; I CHANGED TO UNICOM FREQUENCY AND ANNOUNCED MY INTENTIONS; INCLUDING A STATEMENT THAT I HAD AN EMER. OTHER ACFT APCHING THE ARPT GAVE WAY AND I LANDED WITHOUT FURTHER INCIDENT. AFTER LNDG I SUMPED THE GASCOLATOR AND FUSELAGE TANKS BUT FOUND NO EVIDENCE OF CONTAMINATED FUEL. MY MECHANIC ARRIVED; WE UNCOWLED THE AIRPLANE AND DISCONNECTED THE FUEL SOURCE LINE FROM THE SERVO. EACH SELECTED TANK WAS ABLE TO SOURCE FUEL INTO THE INJECTOR; THE FUEL; CAPTURED IN A CONTAINER; APPEARED UNCONTAMINATED. I LATER CONTACTED THE US IMPORTER OF THE AIRPLANE; EXPLAINED THE CIRCUMSTANCES; THEY ARE ADVISING ON HOW TO INVESTIGATE THE PROBLEM. WHAT WOULD I HAVE DONE DIFFERENTLY? IF I HAD TIME; I'D HAVE CONTACTED THE TRACON AND INFORMED THEM OF THE SITUATION; GIVEN THAT WING FUEL EXHAUSTION WAS IMMINENT; THOUGH; MY SOLE FOCUS WAS GETTING THE AIRPLANE SAFELY ON THE GND; PREFERABLY AT AN ARPT. I'D ALSO HAVE SET MY TRANSPONDER ON 7700; WHICH WOULD HAVE BEEN USEFUL FOR TRACKING PURPOSES IN CASE I NEEDED TO LAND OFF ARPT. MY WINGMAN HOWEVER; HAD ME IN SIGHT FOR THE ENTIRETY OF MY DSCNT AND LNDG AT ZZZ.CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: AN AIRWORTHINESS DIRECTIVE EXISTS FOR THE FUEL SELECTOR IN THIS ACFT AND IT WILL BE REPLACED BEFORE THE NEXT FLIGHT. THE 'O' RINGS IN THIS SELECTOR TEND TO DETERIORATE AND CAUSE LEAKS BUT HAVE NOT BEEN RPTED TO CAUSE FLOW PROBLEMS. THE RPTR FLEW THROUGH LIGHT RAIN AT NEAR FREEZING TEMPERATURES; THEN CLBED TO BELOW FREEZING TEMPERATURES AND BELIEVES THAT TANK VENT ICING MAY BE THE SOURCE OF THE PROBLEM.

Data retrieved from NASA's ASRS site as of May 2009 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.