What happened
The accident occurred during a routine engine start procedure that required manual assistance. The pilot attempted to start the engine by hand propping, a method where an individual stands near the propeller to rotate it manually while the ignition is engaged. During this operation, the engine successfully started; however, the aircraft immediately began to move forward without control.
The primary factor in the loss of control was that the throttle lever had been left in the full open position. Because the pilot had neglected to tie down the airplane prior to initiating the start sequence, there was no mechanical restraint to hold the aircraft in place against the sudden torque and thrust generated by the engine. As the engine fired, the unbraked aircraft accelerated rapidly, kicking up debris from the ground.
The force of the moving aircraft caused the pilot to lose his footing and fall to the ground. The airplane continued its forward momentum, traveling several hundred yards across the airfield surface. Eventually, the aircraft ran out of clear space and impacted the ground at speed, resulting in a nosing over incident that damaged the airframe.
The investigation
Post-acc examination revealed that the aircraft had not been secured with chocks or tie-downs before the start attempt. The throttle linkage was found in the full forward position, confirming that the pilot had not moved it to idle as intended. The lack of physical restraint allowed the engine's power to translate directly into uncontrolled ground movement.
Findings
The investigation determined that the accident was caused by a series of procedural errors during the pre-flight preparation and start sequence. The pilot failed to secure the aircraft with tie-downs or wheel chocks, which is a standard safety practice for any engine start operation. Additionally, the pilot incorrectly assumed the throttle was near idle when it was actually fully open. These oversights resulted in the aircraft becoming a runaway vehicle during the critical moment of ignition.
Safety message
This incident highlights the critical importance of securing an aircraft before starting the engine. Pilots must always ensure that tie-downs are engaged and wheel chocks are in place to prevent unintended movement. Furthermore, verifying the throttle position is idle before attempting a hand start is essential to avoid sudden acceleration.