Engine Failure Forces Agricultural Pilot to Land in Citrus Grove (N21676)

Accident

An aerial application flight was conducting its second tract run of the day. As the pilot initiated a pull-up from an altitude between 100 and 150 feet above ground level, the engine emitted a 'clunk' sound and ceased operation. With limited altitude available, the pilot determined that the only viable option was to execute a forced landing into a 'wide row' within the citrus grove.

Investigation

Subsequent examination of the engine disclosed that a crankshaft counterweight retaining pin had migrated from its intended installed position. This displacement resulted in catastrophic internal failure of the engine, leading to the loss of power.

Conclusion

The probable cause of the accident is the migration of the crankshaft counterweight retaining pin, which caused catastrophic internal engine failure and subsequent power loss.