Schleicher Gmbh & Co ASH 31 MI N20SW accident near Winter Haven, Florida

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.

NTSB analysis

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.

Text from the NTSB. Open the NTSB docket for ERA24LA228 for the full record.