What happened
On August 29, 2015, at approximately 12:15 UTC, an SMG-92 Turbo Finist, registration HA-YDJ, was performing its 13th takeoff of the day at Casale Monferrato airport. Shortly after liftoff, while still within the airport perimeter on the runway, the aircraft suffered a total loss of engine power. The aircraft lost altitude and struck the airport fence before hitting trees and coming to rest against the edge of a ditch just outside the airfield boundary. The aircraft was destroyed in the impact.
There were 11 people on board, including the pilot and ten skydivers (three of whom were tandem passengers with instructors). The accident resulted in multiple injuries, with several occupants sustaining serious trauma, including fractures, head injuries, and internal organ damage.
The investigation
The ANSV investigation focused on the mechanical failure of the engine and the maintenance oversight of the aircraft. Investigators examined the M601D engine and found that the engine had exceeded its maximum allowable cycles before a required overhaul. Specifically, while the operator reported 115 starts during the period between August 2014 and August 2015, the investigation estimated the actual number of starts was approximately 285. Based on the maintenance manual's formula for equivalent cycles, the engine had surpassed the 672-cycle limit for overhaul.
Furthermore, the investigation looked into the regulatory status of the aircraft. The HA-YDJ was registered in Hungary and operated under a certificate of airworthiness that allowed for flight and landing in Italy, but not for continuous commercial operations such as skydiving schools. The investigation also noted that the skydiving school was operating without a COLA (Certificate of Air Operator Authorization) at the time.
Findings
- The primary cause of the crash was an engine failure caused by a loss of connection in the power module between the quill shaft and the PT shaft.
- The aircraft operator's maintenance control system was insufficient and failed to accurately report critical engine life parameters.
- There was a lack of adequate restraint systems, such as seatbelts, for the skydivers on board, which contributed to the severity of the injuries as occupants were thrown against the aircraft structure.
- National regulations at the time lacked sufficient technical oversight for foreign-registered aircraft performing continuous skydiving operations on Italian territory.