Accident Details
On August 8, 2009, at about 0945 central daylight time, a Schempp-Hirth Ventus 2cM powered glider, registration N70ZZ, impacted terrain while returning to land after a reported partial loss of engine power during the initial takeoff climb from St Elmo Airport (2R5) in St Elmo, Alabama. The flight was a personal local flight under 14 CFR Part 91, conducted in visual meteorological conditions. No flight plan was filed. The powered glider sustained substantial damage. The private pilot, the sole occupant, sustained minor injuries. The flight was originating at the time of the accident.
Pilot Account
The pilot reported that before takeoff, the fuselage fuel tank was full with 100 low lead (100LL) fuel. He was unable to check for contaminants due to the sump drain location. During the engine run-up, he observed a 100 and 200 rpm drop when checking each ignition system, but could not recall which system had which drop. He began the takeoff roll from runway 06 with wind from the east-southeast at 5 to 6 knots. Based on his 400 hours of powered glider experience, the takeoff roll was longer than normal. After reaching between 150 and 200 feet, engine rpm dropped to approximately 70 to 80 percent of full power. The powered glider climbed slowly. The pilot considered landing straight ahead or returning for landing; he chose to return, believing the engine had enough power. While turning downwind, the powered glider felt mushy, and he realized he would not make it back. He applied forward elevator input, and the powered glider impacted the ground in a slight right-wing-low attitude, resulting in substantial damage to the fuselage, right wing, and tail assemblies. The pilot exited and removed the wreckage before an FAA inspector could inspect it.
Post-Accident Inspection
An independent airframe and power plant (A&P) mechanic was hired to examine the powered glider approximately three months after the accident, as inspection with FAA oversight could not be coordinated. Upon delivery, the mechanic was told and it was evident that the owner had partially disassembled the engine. The inspection found the ignition system worked properly and no definitive evidence of pre-impact anomalies that would have caused the partial loss of engine power. Damage to the cylinder walls was observed, but it could not be correlated with the power loss due to the prior disassembly.