Narrative:

During level flight during solo cross country training in day VFR conditions; I experienced a partial engine failure. I was at 3500 ft MSL cruising at 94 KTS TAS with the engine set at 2400 RPM the engine began to run rough. I put the mixture in full rich with the problem getting worse. I put the carburetor heat on and trimmed the C150 to its best glide speed. Within 30 seconds; the engine at full power would only develop 1700-1800 RPM. At that time I turned 180 degrees into the wind while putting a direct to ZZZ1 airport. I was tuned on the ZZZ1 VOR and centered the needle so as to not drift my course. I then checked both magnetos and engine oil pressure/temperature; all of which were normal. I was over rolling hills and knew I wasn't going to make the airport. As I passed through 2500 ft; I tuned my transponder to 7700 and began making mayday calls on 121.5. As I descended; nobody responded; so I tuned the radio to 122.8 (the CTAF for both ZZZ1 and nearby ZZZ2). I heard traffic in the pattern at ZZZ2. I transmitted my mayday as well as my latitude/longitude off my GPS. Nobody responded again. As I passed through 1700 ft MSL; I saw a small set of telephone lines in my original landing area. With partial power applied; I was unable to maintain my altitude; but could reduce my rate of descent. I dropped 10 degrees of flaps to gain lift and banked hard at about 300 ft. I crossed a hedgerow of 80 ft trees; knowing I would make my landing area dropped full flaps to get down; because slipping the aircraft into the field would not have allowed me to line up with the rows in the field made by the owner's tractor. At about 15 ft AGL; I cut the fuel off to the motor; and pulled the engine off. At 5 ft; I flared holding the nose up until I heard the stall horn. I continued to hold the nose off as the mains touched. I applied full brake pressure after the nose settled. The aircraft was landed with about 75 ft of ground run and no damage. The cause of the failure is believed to be a dropped cylinder or valve. As a student fixed wing pilot; I was able to use my experience as a commercial instrument helicopter pilot to safely land the aircraft without damage. I attribute this to proper emergency procedures; and a thorough understanding of aerodynamics. My primary safety concerns are why nobody answered me on guard or saw my transponder. When I switched to CTAF; I could hear traffic from along way from my position. Why did the aircraft in the pattern at ZZZ2 not respond either.

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Original NASA ASRS Text

Title: C150 STUDENT PLT EXPERIENCES ENG FAILURE AND MAKES AN EMER LNDG IN A FIELD.

Narrative: DURING LEVEL FLT DURING SOLO XCOUNTRY TRAINING IN DAY VFR CONDITIONS; I EXPERIENCED A PARTIAL ENG FAILURE. I WAS AT 3500 FT MSL CRUISING AT 94 KTS TAS WITH THE ENG SET AT 2400 RPM THE ENG BEGAN TO RUN ROUGH. I PUT THE MIXTURE IN FULL RICH WITH THE PROB GETTING WORSE. I PUT THE CARB HEAT ON AND TRIMMED THE C150 TO ITS BEST GLIDE SPD. WITHIN 30 SECONDS; THE ENG AT FULL PWR WOULD ONLY DEVELOP 1700-1800 RPM. AT THAT TIME I TURNED 180 DEGS INTO THE WIND WHILE PUTTING A DIRECT TO ZZZ1 ARPT. I WAS TUNED ON THE ZZZ1 VOR AND CTRED THE NEEDLE SO AS TO NOT DRIFT MY COURSE. I THEN CHKED BOTH MAGNETOS AND ENG OIL PRESSURE/TEMP; ALL OF WHICH WERE NORMAL. I WAS OVER ROLLING HILLS AND KNEW I WASN'T GOING TO MAKE THE ARPT. AS I PASSED THROUGH 2500 FT; I TUNED MY XPONDER TO 7700 AND BEGAN MAKING MAYDAY CALLS ON 121.5. AS I DSNDED; NOBODY RESPONDED; SO I TUNED THE RADIO TO 122.8 (THE CTAF FOR BOTH ZZZ1 AND NEARBY ZZZ2). I HEARD TFC IN THE PATTERN AT ZZZ2. I XMITTED MY MAYDAY AS WELL AS MY LATITUDE/LONGITUDE OFF MY GPS. NOBODY RESPONDED AGAIN. AS I PASSED THROUGH 1700 FT MSL; I SAW A SMALL SET OF TELEPHONE LINES IN MY ORIGINAL LNDG AREA. WITH PARTIAL PWR APPLIED; I WAS UNABLE TO MAINTAIN MY ALT; BUT COULD REDUCE MY RATE OF DSCNT. I DROPPED 10 DEGS OF FLAPS TO GAIN LIFT AND BANKED HARD AT ABOUT 300 FT. I CROSSED A HEDGEROW OF 80 FT TREES; KNOWING I WOULD MAKE MY LNDG AREA DROPPED FULL FLAPS TO GET DOWN; BECAUSE SLIPPING THE ACFT INTO THE FIELD WOULD NOT HAVE ALLOWED ME TO LINE UP WITH THE ROWS IN THE FIELD MADE BY THE OWNER'S TRACTOR. AT ABOUT 15 FT AGL; I CUT THE FUEL OFF TO THE MOTOR; AND PULLED THE ENG OFF. AT 5 FT; I FLARED HOLDING THE NOSE UP UNTIL I HEARD THE STALL HORN. I CONTINUED TO HOLD THE NOSE OFF AS THE MAINS TOUCHED. I APPLIED FULL BRAKE PRESSURE AFTER THE NOSE SETTLED. THE ACFT WAS LANDED WITH ABOUT 75 FT OF GND RUN AND NO DAMAGE. THE CAUSE OF THE FAILURE IS BELIEVED TO BE A DROPPED CYLINDER OR VALVE. AS A STUDENT FIXED WING PLT; I WAS ABLE TO USE MY EXPERIENCE AS A COMMERCIAL INST HELI PLT TO SAFELY LAND THE ACFT WITHOUT DAMAGE. I ATTRIBUTE THIS TO PROPER EMER PROCS; AND A THOROUGH UNDERSTANDING OF AERODYNAMICS. MY PRIMARY SAFETY CONCERNS ARE WHY NOBODY ANSWERED ME ON GUARD OR SAW MY XPONDER. WHEN I SWITCHED TO CTAF; I COULD HEAR TFC FROM ALONG WAY FROM MY POS. WHY DID THE ACFT IN THE PATTERN AT ZZZ2 NOT RESPOND EITHER.

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.