Primary finding
Probable cause
The pilot’s failure to ensure that a suitable landing area was available in case the restart of the motor glider’s engine was unsuccessful. Contributing, was insufficient battery charge to extend the motor glider’s pylon assembly.
Investigator assessment
Analysis narrative
The pilot reported that the motor glider’s engine and propeller pylon assembly operated normally for the takeoff and climb to 2,500 ft mean sea level (msl); however, he forgot to turn off the engine’s second fuel pump during the climb, which could potentially drain the battery. After reaching 2,500 ft msl, the pilot shut down the engine and stowed the propeller pylon assembly. After several minutes of soaring, the pilot realized that there were no thermals and that he had insufficient altitude to return to the airport. The pilot attempted to start the engine; however, the propeller pylon assembly would not fully extend. The pilot then attempted to land at a nearby football field, where the motor glider impacted trees and came to rest inverted on a road. The motor glider was recovered to a local impound lot after the accident; however, shortly after recovery, the owner/pilot sold the wreckage without authorization, therefore the wreckage could not be examined in detail. No determination of the battery’s charge state could be made after the accident. The new owner of the fuselage, engine, and propeller pylon reported that the linear actuator that drove the pylon operated normally when electrical power was applied to the motor. Based on the available information, it is likely that during the accident flight the battery that operated the propeller pylon assembly was depleted such that insufficient charge remained to extend the pylon assembly.
Source record
Factual narrative
On May 25, 2024, at 1350 eastern daylight time, an Alexander Schleicher ASH 31 glider, N20SW, was substantially damaged when it was involved in an accident near Winter Haven, Florida. The pilot sustained minor injuries. The glider was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. According to the pilot, the weather was good for soaring, and he planned to perform a flight in the local area. He reported that the motor glider’s engine and propeller drive operated normally for the takeoff and climb to 2,500 ft mean sea level (msl); however, the pilot stated that he forgot to turn off the engine’s second fuel pump during the climb, which could potentially drain the battery. Upon reaching 2,500 ft msl the pilot shut down the engine and stowed the propeller pylon assembly. He began to soar to a location where he anticipated good thermals. After a few minutes of soaring, the pilot realized that there were no thermals in the area and that he didn’t have enough altitude to return to the airport. The pilot attempted to start the engine; however, the propeller pylon assembly did not fully extend out of the fuselage. After determining that the engine and propeller pylon assembly could not be used to regain altitude, the pilot elected to perform a landing to a nearby football field. While on approach to the football field, the motor glider impacted trees and came to rest inverted on a road in a residential area. Postaccident examination of the motor glider by an FAA inspector revealed substantial damage to the wings and fuselage. The motor glider was recovered to a local impound lot; however, shortly after recovery, the owner/pilot sold the wreckage before it could be examined in detail and no determination of the battery’s charge state could be made. The new owner of the fuselage, engine, and propeller pylon reported that the propeller pylon was capable of moving between the stowed and extended position without any anomalies. The linear actuator that drove the pylon was tested and operated normally when 12-volt electrical power was applied to the motor.