Narrative:

A neighbor requested I fly his cub as he had had some surgery and the plane hadn't been used for 3-4 weeks. Normal preflight completed with no discrepancies noted. Start-up, taxi and takeoff were normal. Approximately 150 ft up and 1/4 mi past south end of our grass strip, I reduced power very slightly. 1 or 2 seconds later, the engine spooled down and quit. I started a right turn back towards runway, checked magnetos on both and fuel still on, which both items were. Approximately 90 degrees to runway I decided there was no way I would make it back, so I continued straight ahead and landed in an open field, which, although muddy from recent rain, was firm enough for a cub. No damage to me, property, or the plane. All of this occurred within sight and sound of our airpark. Several neighbors arrived promptly, including a mechanic who does the maintenance for the owner. He checked the plane, especially the fuel drain, and found no obvious problem. Temperature was about 70 degrees with moderate humidity. There was a fair amount of condensation on the carburetor and he suspected it was a carburetor ice situation. Engine restarted on first attempt and run at various power settings for several mins. All seemed ok so I took off and landed immediately on our strip with no problem. Ai later pulled the carburetor bowl and fuel screen, and found no solid contaminants. We conclude it was indeed a carburetor ice incident. I had always associated carburetor ice with reduced power settings, as in landing, but will certainly be more aware of the possibility at other stages of a flight from now on.

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Original NASA ASRS Text

Title: A HIGHLY EXPERIENCED PLT, FLYING A CUB AT 83R, WAS TAKING OFF WHEN CARB ICE BUILT UP, CAUSING THE ENG TO QUIT. THE RPTR MADE AN OFF ARPT FORCED LNDG.

Narrative: A NEIGHBOR REQUESTED I FLY HIS CUB AS HE HAD HAD SOME SURGERY AND THE PLANE HADN'T BEEN USED FOR 3-4 WKS. NORMAL PREFLT COMPLETED WITH NO DISCREPANCIES NOTED. START-UP, TAXI AND TKOF WERE NORMAL. APPROX 150 FT UP AND 1/4 MI PAST S END OF OUR GRASS STRIP, I REDUCED PWR VERY SLIGHTLY. 1 OR 2 SECONDS LATER, THE ENG SPOOLED DOWN AND QUIT. I STARTED A R TURN BACK TOWARDS RWY, CHKED MAGNETOS ON BOTH AND FUEL STILL ON, WHICH BOTH ITEMS WERE. APPROX 90 DEGS TO RWY I DECIDED THERE WAS NO WAY I WOULD MAKE IT BACK, SO I CONTINUED STRAIGHT AHEAD AND LANDED IN AN OPEN FIELD, WHICH, ALTHOUGH MUDDY FROM RECENT RAIN, WAS FIRM ENOUGH FOR A CUB. NO DAMAGE TO ME, PROPERTY, OR THE PLANE. ALL OF THIS OCCURRED WITHIN SIGHT AND SOUND OF OUR AIRPARK. SEVERAL NEIGHBORS ARRIVED PROMPTLY, INCLUDING A MECH WHO DOES THE MAINT FOR THE OWNER. HE CHKED THE PLANE, ESPECIALLY THE FUEL DRAIN, AND FOUND NO OBVIOUS PROB. TEMP WAS ABOUT 70 DEGS WITH MODERATE HUMIDITY. THERE WAS A FAIR AMOUNT OF CONDENSATION ON THE CARB AND HE SUSPECTED IT WAS A CARB ICE SIT. ENG RESTARTED ON FIRST ATTEMPT AND RUN AT VARIOUS PWR SETTINGS FOR SEVERAL MINS. ALL SEEMED OK SO I TOOK OFF AND LANDED IMMEDIATELY ON OUR STRIP WITH NO PROB. AI LATER PULLED THE CARB BOWL AND FUEL SCREEN, AND FOUND NO SOLID CONTAMINANTS. WE CONCLUDE IT WAS INDEED A CARB ICE INCIDENT. I HAD ALWAYS ASSOCIATED CARB ICE WITH REDUCED PWR SETTINGS, AS IN LNDG, BUT WILL CERTAINLY BE MORE AWARE OF THE POSSIBILITY AT OTHER STAGES OF A FLT FROM NOW ON.

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.