Amateur-built ZENAIR CH 601 HD N905KM accident near Lebanon, Indiana

Probable cause

The loss of lateral/bank control during takeoff due to the pilot’s decision to operate the airplane with a known fuel imbalance.

NTSB analysis

The pilot was performing a maintenance test flight following a recent condition inspection. Due to a persistent fuel leak in the right wing fuel tank, the pilot had about 11 gallons of fuel in the left wing fuel tank and the right fuel tank was empty. Before takeoff, the pilot checked all flight controls with no anomalies noted. The pilot reported that shortly after being out of ground effect during the takeoff, the airplane began to roll to the left. The pilot attempted to correct with right aileron control but was unsuccessful. The pilot pulled the throttle to idle, and the left roll continued until the left wingtip struck the terrain. The airplane cartwheeled into a cornfield adjacent to the runway, came to rest upright, and sustained substantial damage to the fuselage. The pilot reported that there were no preaccident mechanical malfunctions or failures with the airplane that would have precluded normal operation. It is likely the known fuel imbalance resulted in a left roll tendency that could not be corrected with the flight controls during the takeoff.

Text from the NTSB. Open the NTSB docket for CEN22LA426 for the full record.