Narrative:

Briefly, I experienced carburetor icing and successfully landed off airport with no damage to aircraft, property, or persons. Power loss was partial but I couldn't make it to the runway. I simply failed to recognize the carburetor ice and apply carburetor heat. Subtle engine changes are hard to realize in the loud, rough cabin of the super cub. At dusk on mar/xx/95, while approaching to land at mck, northeast, I experienced carburetor ice resulting in an off airport landing. The event occurred at the end of a long eastbound flight, approaching darkness, greater than forecast headwinds which were uncustomarily out of the east rather than the west, and a long descent (5500 ft down to traffic pattern altitude). Because of these stress factors, I failed to apply carburetor heat. There was no time to consult a checklist. Maintaining control and finding a suitable landing site were my primary focus. After 750 hours in a PA18-150 and many instances of carburetor icing at all RPM's and flight sits, I still have trouble recognizing carburetor icing and believe it's due to the high noise environment and vibrations of the PA18-150. In the PA18-150 super cub, one does not hear the RPM drop or feel the roughness of the engine usually associated with carburetor icing as in other aircraft. To prevent a recurrence, pilots of PA18-150's need to pay special attention to carburetor icing in any flight confign. Perhaps a placard warning of this special problem of PA18-150's is warranted.

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Original NASA ASRS Text

Title: OFF ARPT LNDG BECAUSE OF CARB ICING.

Narrative: BRIEFLY, I EXPERIENCED CARB ICING AND SUCCESSFULLY LANDED OFF ARPT WITH NO DAMAGE TO ACFT, PROPERTY, OR PERSONS. PWR LOSS WAS PARTIAL BUT I COULDN'T MAKE IT TO THE RWY. I SIMPLY FAILED TO RECOGNIZE THE CARB ICE AND APPLY CARB HEAT. SUBTLE ENG CHANGES ARE HARD TO REALIZE IN THE LOUD, ROUGH CABIN OF THE SUPER CUB. AT DUSK ON MAR/XX/95, WHILE APCHING TO LAND AT MCK, NE, I EXPERIENCED CARB ICE RESULTING IN AN OFF ARPT LNDG. THE EVENT OCCURRED AT THE END OF A LONG EBOUND FLT, APCHING DARKNESS, GREATER THAN FORECAST HEADWINDS WHICH WERE UNCUSTOMARILY OUT OF THE E RATHER THAN THE W, AND A LONG DSCNT (5500 FT DOWN TO TFC PATTERN ALT). BECAUSE OF THESE STRESS FACTORS, I FAILED TO APPLY CARB HEAT. THERE WAS NO TIME TO CONSULT A CHKLIST. MAINTAINING CTL AND FINDING A SUITABLE LNDG SITE WERE MY PRIMARY FOCUS. AFTER 750 HRS IN A PA18-150 AND MANY INSTANCES OF CARB ICING AT ALL RPM'S AND FLT SITS, I STILL HAVE TROUBLE RECOGNIZING CARB ICING AND BELIEVE IT'S DUE TO THE HIGH NOISE ENVIRONMENT AND VIBRATIONS OF THE PA18-150. IN THE PA18-150 SUPER CUB, ONE DOES NOT HEAR THE RPM DROP OR FEEL THE ROUGHNESS OF THE ENG USUALLY ASSOCIATED WITH CARB ICING AS IN OTHER ACFT. TO PREVENT A RECURRENCE, PLTS OF PA18-150'S NEED TO PAY SPECIAL ATTN TO CARB ICING IN ANY FLT CONFIGN. PERHAPS A PLACARD WARNING OF THIS SPECIAL PROB OF PA18-150'S IS WARRANTED.

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.