Narrative:

When I arrived at swf I told the FBO to top off both fuel tanks with 100LL gas. It was a sunny warm day. My passenger and I went to inspect a local job site. We returned to stewart approximately XX15. I got a WX briefing and filed an IFR flight plan. After preflting the aircraft (including a thorough examination of the fuel tank and caps. The tanks were full to the top. When I rocked the wings I could see fuel coming from the vents) I picked up my clearance. My clearance was different than what I filed for. I reviewed my new route then taxied out and did my run-up using my checklists for each activity. We departed on runway 27 directly into bright sunshine. At approximately 1200 ft we noticed fuel coming out of the right fuel tank. I notified stewart tower that I was going to come back and land. The controller asked what was wrong. I told him I had fuel leaking from my right wing. He cleared me to land on any runway. I performed the prelndg checklist on downwind and told my passenger that we were going to land and when the plane stopped we would get out of the plane right away. On short final the controller informed me he was going to roll the crash trucks. I told him we were doing fine. We landed, stopped and got out of the plane. The crash crews met us and looked the plane over. We could find nothing that seemed wrong with the cap. I inspected the o-ring and mechanism. It seemed fine. After looking at my left fuel cap it looked like it was different than my right cap. I removed it and checked both caps. The tank was still full. I did another preflight (using my checklists). I contacted ground and was cleared to taxi to runway 27. On my takeoff roll at approximately 30 KTS, I noticed fuel coming out of the right cap. I aborted the takeoff. I taxied back to the FBO where I bought the fuel. They sent a mechanic to look at the cap. He removed the cap and disassembled it. He told me he did not find anything obviously wrong with the cap but while we had it apart he replaced both o-rings. We decided to fly around the pattern while we watched to see if any fuel was leaking. The cap was fine, no leaking. We came back and landed. I got a new briefing, filed my flight plan, preflted the plane. I contacted ground, got my clearance and departed.

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Original NASA ASRS Text

Title: FUEL SYPHONING FROM FUEL CAP. RETURN LAND.

Narrative: WHEN I ARRIVED AT SWF I TOLD THE FBO TO TOP OFF BOTH FUEL TANKS WITH 100LL GAS. IT WAS A SUNNY WARM DAY. MY PAX AND I WENT TO INSPECT A LCL JOB SITE. WE RETURNED TO STEWART APPROX XX15. I GOT A WX BRIEFING AND FILED AN IFR FLT PLAN. AFTER PREFLTING THE ACFT (INCLUDING A THOROUGH EXAMINATION OF THE FUEL TANK AND CAPS. THE TANKS WERE FULL TO THE TOP. WHEN I ROCKED THE WINGS I COULD SEE FUEL COMING FROM THE VENTS) I PICKED UP MY CLRNC. MY CLRNC WAS DIFFERENT THAN WHAT I FILED FOR. I REVIEWED MY NEW RTE THEN TAXIED OUT AND DID MY RUN-UP USING MY CHKLISTS FOR EACH ACTIVITY. WE DEPARTED ON RWY 27 DIRECTLY INTO BRIGHT SUNSHINE. AT APPROX 1200 FT WE NOTICED FUEL COMING OUT OF THE R FUEL TANK. I NOTIFIED STEWART TWR THAT I WAS GOING TO COME BACK AND LAND. THE CTLR ASKED WHAT WAS WRONG. I TOLD HIM I HAD FUEL LEAKING FROM MY R WING. HE CLRED ME TO LAND ON ANY RWY. I PERFORMED THE PRELNDG CHKLIST ON DOWNWIND AND TOLD MY PAX THAT WE WERE GOING TO LAND AND WHEN THE PLANE STOPPED WE WOULD GET OUT OF THE PLANE RIGHT AWAY. ON SHORT FINAL THE CTLR INFORMED ME HE WAS GOING TO ROLL THE CRASH TRUCKS. I TOLD HIM WE WERE DOING FINE. WE LANDED, STOPPED AND GOT OUT OF THE PLANE. THE CRASH CREWS MET US AND LOOKED THE PLANE OVER. WE COULD FIND NOTHING THAT SEEMED WRONG WITH THE CAP. I INSPECTED THE O-RING AND MECHANISM. IT SEEMED FINE. AFTER LOOKING AT MY L FUEL CAP IT LOOKED LIKE IT WAS DIFFERENT THAN MY R CAP. I REMOVED IT AND CHKED BOTH CAPS. THE TANK WAS STILL FULL. I DID ANOTHER PREFLT (USING MY CHKLISTS). I CONTACTED GND AND WAS CLRED TO TAXI TO RWY 27. ON MY TKOF ROLL AT APPROX 30 KTS, I NOTICED FUEL COMING OUT OF THE R CAP. I ABORTED THE TKOF. I TAXIED BACK TO THE FBO WHERE I BOUGHT THE FUEL. THEY SENT A MECH TO LOOK AT THE CAP. HE REMOVED THE CAP AND DISASSEMBLED IT. HE TOLD ME HE DID NOT FIND ANYTHING OBVIOUSLY WRONG WITH THE CAP BUT WHILE WE HAD IT APART HE REPLACED BOTH O-RINGS. WE DECIDED TO FLY AROUND THE PATTERN WHILE WE WATCHED TO SEE IF ANY FUEL WAS LEAKING. THE CAP WAS FINE, NO LEAKING. WE CAME BACK AND LANDED. I GOT A NEW BRIEFING, FILED MY FLT PLAN, PREFLTED THE PLANE. I CONTACTED GND, GOT MY CLRNC AND DEPARTED.

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.