Event Description
On 6 October 2018, at the EPZA airport in Zamość, a Cessna U206G was conducting parachute jump operations. The ninth flight of the day departed at 17:30 with five parachutists on board. During the takeoff roll, engine parameters were normal. After rotation, at approximately 5 meters above ground, the engine lost power. The pilot immediately aborted the takeoff, landed safely on the runway, and brought the aircraft to a stop. Due to smoke and a suspected engine fire, the pilot ordered an evacuation, which was completed successfully with no injuries. Subsequent inspection found no fire, but a hole had been punched in the crankcase by the connecting rod of the third cylinder.
Investigation and Findings
An investigation revealed that the engine monitor (JPI EDM 830W) had, for unknown reasons, changed its recording interval from every 6 seconds to every 8 minutes and 30 seconds starting in July 2018. This prevented the capture of any exceedance parameters. The engine was further examined at LOMA AIR in Belgium, where numerous mechanical damages were found, caused by a broken connecting rod bolt. The destruction began with a crack in the bolt holding the connecting rod, which then broke under the forces of high engine RPMs, leading to progressive degradation of engine components.
Probable Cause
The probable cause of the incident was exceeding the engine's maximum rotational speed (over-revving) during a previous flight, which led to engine damage.