Date: 201507
Local time of day: 1801-2400
Location: ZZZ.Airport, US
Flight conditions: VMC
Weather elements / visibility: 8
Light: Dusk
Aircraft: Cheetah; Tiger; Traveler AA5 Series
Operator: Personal
Operating under: Part 91
Flight plan: None
Mission: Personal
Flight phase: Final Approach
Airspace: Class D ZZZ
ATC / advisory: Tower ZZZ
Aircraft component: Engine
Component problem: Malfunctioning
Reporter organization: Personal
Reporter function: Pilot Flying; Instructor
Reporter qualification: Flight Crew Multiengine; Flight Crew Commercial; Flight Crew Flight Instructor; Flight Crew Instrument
Human factors: Confusion; Time Pressure; Troubleshooting
Anomaly: Aircraft Equipment Problem Critical; Inflight Event / Encounter Fuel Issue; Inflight Event / Encounter Loss Of Aircraft Control
Detector: Person Flight Crew
When detected: In-flight
Result: Aircraft Aircraft Damaged; Flight Crew Landed in Emergency Condition
Contributing factors: Aircraft; Weather
Primary problem: Aircraft

Narrative: I was doing pattern work making left hand traffic patterns.  The landings were touch and goes.  After the second landing I requested a full stop landing and was going to park the airplane and be finished for the evening.  At 600 AGL on the base to final turn to the runway the engine power unit failed.  It was a partial power loss with no throttle response.  The engine remained at or below 1000 RPM and was not responsive to a restart after switching the fuel tanks and adjusting the throttle to see if there was any change.The airplane was fueled before departure with approximately 13 gallons out of a total of 22 gallons possible for both wing tanks.  Upon looking to see if there was sufficient altitude to attempt a power off glide to the runway I decided that the altitude was not sufficient to clear the many houses and structures between the aircraft position and the runway.  I radioed the tower and announced a mayday call on ZZZ Tower frequency.I maneuvered the aircraft to the northeast from the base leg and aimed for the darkness to which I thought was a field.  Upon an altitude of approximately 100AGL the airplane landing light illuminated the field in front of me to which I lowered the nose to be sure that the aircraft would have a sufficient landing roll to get stopped to avoid hitting any structures or immobile objects on the other side of the cornfield.  Upon impact with the corn the airplane slowed rapidly and the nose wheel hit the dirt which caused the aircraft to go airborne approximately 4 to 6 feet causing the aircraft to come to a rest on its back and had flipped over.Upon checking on my passenger to see that he was still alive and responsive we both undid our seat belts and being upside down we both came in contact with the ground.  We broke a portion of the already broken glass canopy and crawled out from underneath the aircraft and began making phone calls to 911 and the airport Tower.  Upon contact with the Tower I alerted him that we were alive and walking with minor injuries that were non-life threatening.  First responders arrived at the scene and we were both cleared of medical treatment and were allowed to leave the scene.  I was un-aware of any maintenance issues that would have caused the aircraft to be un-airworthy at the time of departure.




Synopsis: An AA-1B Grumman Tiger pilot experienced partial engine failure while in a landing pattern.  The engine would not produce more than 1000 rpm and he judged that he would be unable to make it to the runway.  He landed in a cornfield. The aircraft flipped over but the pilot and his passenger were unhurt.