What happened
On August 1, 2001, at Rieti Airport, a mid-air collision occurred between two Stinson L5 aircraft, registrations I-AEEX and I-AEGN, during a glider towing operation for the Mediterranean International Cup.
The sequence of events involved several aircraft operating in close succession. Following the departure of several tow planes, the pilot of I-AEEX attempted to shorten the downwind leg by performing a tight right-hand base turn to land on the left side of runway 3. During this maneuver, the pilot failed to notice that I-AEGN was already on short final, also aligned with the left side of the same runway. As I-AEGN was completing its landing roll, it was struck by the landing gear of I-AEEX, which was performing its final flare. The impact caused the nose of I-AEE to drop, and both aircraft subsequently pitched up vertically before coming to a stop. Both pilots escaped the wreckage without injuries, though both aircraft sustained severe damage.
The investigation
The ANSV investigation examined the flight operations, the technical condition of the aircraft, and the organizational procedures in place during the competition. The investigation noted that the pilots were properly licensed and experienced, and the aircraft were in an airworthy condition.
Investigators found that the competition organizers had implemented specific procedures that deviated from standard AIP Italia regulations. Specifically, the race director had instructed pilots to avoid position reports on the radio frequency to keep it clear for emergencies. Furthermore, the takeoff and landing intervals were extremely compressed, with multiple aircraft departing and arriving in a very short timeframe. The investigation also noted that the use of runway 3 involved using a grass strip designated as a taxiway, and pilots were given significant discretion regarding which side of the runway to use for landing.
Findings
- The primary cause of the accident was the failure to maintain visual separation principles, specifically the pilot of I-AEEX failing to monitor the final approach segment of the traffic pattern to ensure it was clear of other aircraft.
- The pilot of I-AEEX did not follow the standard traffic pattern procedures during the approach and landing phase.
- The pilot of I-AEGN was unaware of the approaching I-AEEX until the moment of impact.
- The decision by the race director to prohibit radio position reports contributed to the lack of situational awareness.
- The high density of operations and the reduced time intervals between successive takeoffs and landings increased the risk of conflict.
- The high level of discretion allowed to pilots regarding runway usage and landing sides contributed to the collision.