C172 pilot had engine failure and forced landing on takeoff.

Attributes
ACN	514564
Time
Date	200106
Day	Fri
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : gvq.airport
State Reference	NY
Altitude	agl single value : 200
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Operator	general aviation : personal
Make Model Name	Skyhawk 172/Cutlass 172
Operating Under FAR Part	Part 91
Flight Phase	descent : approach
Route In Use	approach : straight in
Flight Plan	None
Person 1
Affiliation	other
Function	flight crew : single pilot
Qualification	pilot : multi engine pilot : commercial pilot : instrument pilot : cfi
Experience	flight time last 90 days : 2.0 flight time total : 2500 flight time type : 800
ASRS Report	514564
Person 2
Affiliation	other
Function	maintenance : technician
Qualification	technician : powerplant technician : airframe
Events
Anomaly	aircraft equipment problem : critical ground encounters : animal ground encounters other other anomaly other
Independent Detector	other flight crewa
Resolutory Action	flight crew : landed in emergency condition none taken : detected after the fact
Consequence	other
Supplementary
Problem Areas	Airport Aircraft
Primary Problem	Ambiguous

Narrative:

Aircraft received a thorough preflight and pretkof checklist. Takeoff initiated on runway 10 at genesee county airport. At 200 ft AGL and 800 ft from departure end of runway 10, the engine failed. It acted as if someone had closed the throttle to idle. The boundary fence and other obstacles were approaching. I elected to close the throttle to avoid the possibility of a power surge. I made a full flap landing on the grass with no damage to the aircraft or objects on ground. I was not hurt. It was a normal grass field landing. The pre takeoff magneto check was totally normal and the engine had been operating normally on previous flts up until failure. Engine ran fine after restart on ground. Subsequent review by an a&P and ia found all fuel and aircraft system normal. Reason for the engine failure was 'butter nuts' in the carburetor air box. Apparently an animal had stored them in the scat tubing and air box for the carburetor heat system. Once the 'butter nuts' were removed, the aircraft was inspected, test flown and returned to service by the a&P and ia. Subsequent operations have been totally normal.

Original NASA ASRS Text

Title: C172 PLT HAD ENG FAILURE AND FORCED LNDG ON TKOF.

Narrative: ACFT RECEIVED A THOROUGH PREFLT AND PRETKOF CHKLIST. TKOF INITIATED ON RWY 10 AT GENESEE COUNTY ARPT. AT 200 FT AGL AND 800 FT FROM DEP END OF RWY 10, THE ENG FAILED. IT ACTED AS IF SOMEONE HAD CLOSED THE THROTTLE TO IDLE. THE BOUNDARY FENCE AND OTHER OBSTACLES WERE APCHING. I ELECTED TO CLOSE THE THROTTLE TO AVOID THE POSSIBILITY OF A PWR SURGE. I MADE A FULL FLAP LNDG ON THE GRASS WITH NO DAMAGE TO THE ACFT OR OBJECTS ON GND. I WAS NOT HURT. IT WAS A NORMAL GRASS FIELD LNDG. THE PRE TKOF MAGNETO CHK WAS TOTALLY NORMAL AND THE ENG HAD BEEN OPERATING NORMALLY ON PREVIOUS FLTS UP UNTIL FAILURE. ENG RAN FINE AFTER RESTART ON GND. SUBSEQUENT REVIEW BY AN A&P AND IA FOUND ALL FUEL AND ACFT SYS NORMAL. REASON FOR THE ENG FAILURE WAS 'BUTTER NUTS' IN THE CARB AIR BOX. APPARENTLY AN ANIMAL HAD STORED THEM IN THE SCAT TUBING AND AIR BOX FOR THE CARB HEAT SYS. ONCE THE 'BUTTER NUTS' WERE REMOVED, THE ACFT WAS INSPECTED, TEST FLOWN AND RETURNED TO SVC BY THE A&P AND IA. SUBSEQUENT OPS HAVE BEEN TOTALLY NORMAL.

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.