Narrative:

I was en route to ZZZ1 from the east. Headwinds were stronger than forecast. Low on fuel when the engine started running rough. I elected to land at ZZZ2; 3 mi away. I made a self-announcement over the CTAF for ZZZ2 declaring an emergency and landed on runway 18. As I taxied to the fuel pump the engine ran smooth again. I put fuel in the plane and did numerous run-ups. The engine ran fine. I elected to go into the on-field restaurant whereupon a man said that I was the first plane into the now opened airport. A short time later the man returned and said that the airport was still closed. I replied that there was no yellow 'X' on the runway for the runway 18 approach. I taxied to the runway 18 departure end for takeoff and noticed a yellow clump off to the right side of the runway. I departed with no further problems. Later I checked and found ZZZ2 to be notamed closed. In the future I think better flight planning is called for.

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Original NASA ASRS Text

Title: PA28 PLT LANDS AT CLOSED ARPT WHEN ENGINE MALFUNCTIONS.

Narrative: I WAS ENRTE TO ZZZ1 FROM THE E. HEADWINDS WERE STRONGER THAN FORECAST. LOW ON FUEL WHEN THE ENG STARTED RUNNING ROUGH. I ELECTED TO LAND AT ZZZ2; 3 MI AWAY. I MADE A SELF-ANNOUNCEMENT OVER THE CTAF FOR ZZZ2 DECLARING AN EMER AND LANDED ON RWY 18. AS I TAXIED TO THE FUEL PUMP THE ENG RAN SMOOTH AGAIN. I PUT FUEL IN THE PLANE AND DID NUMEROUS RUN-UPS. THE ENG RAN FINE. I ELECTED TO GO INTO THE ON-FIELD RESTAURANT WHEREUPON A MAN SAID THAT I WAS THE FIRST PLANE INTO THE NOW OPENED ARPT. A SHORT TIME LATER THE MAN RETURNED AND SAID THAT THE ARPT WAS STILL CLOSED. I REPLIED THAT THERE WAS NO YELLOW 'X' ON THE RWY FOR THE RWY 18 APCH. I TAXIED TO THE RWY 18 DEP END FOR TKOF AND NOTICED A YELLOW CLUMP OFF TO THE R SIDE OF THE RWY. I DEPARTED WITH NO FURTHER PROBS. LATER I CHKED AND FOUND ZZZ2 TO BE NOTAMED CLOSED. IN THE FUTURE I THINK BETTER FLT PLANNING IS CALLED FOR.

Data retrieved from NASA's ASRS site as of January 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.