Incident Summary
On March 14, 2022, at 13:00 UTC, a Piper PA-36-375 (registration CS-DBU) operated by Shamrock, Lda. was conducting an agricultural work training flight at Santarém Aerodrome (LPSR), Portugal. During landing on runway 23 with full flaps (30°), the pilot lost directional control. The aircraft deviated to the right edge of the runway, followed by a 180° ground loop to the left.
Aircraft Information
The aircraft was a Piper Brave PA-36-375, serial number 36-8302017, category airplane. It was configured for agricultural work. The landing gear fracture surface of the right main gear leg showed no pre-event anomalies and exhibited fracture patterns consistent with overload failure, matching the dynamics of the landing and ground loop.
Pilot Experience
The pilot had a total flight experience of 12 hours with 71 landings in tailwheel-configured aircraft. On the accident model, the pilot had recorded 1 hour and 30 minutes of flight time with 8 landings. There was no evidence that any medical condition negatively influenced the occurrence.
Weather Conditions
Meteorological conditions at the time were cloudy sky with visibility of 10 km or more. Temperature was 15°C with a dew point of 6°C. Wind was from the northwest at 9 knots, gusting to 17 knots.
Sequence of Events
While landing on runway 23 with full flaps, the pilot allowed the aircraft to deviate to the right. This initiated a ground loop—an uncontrolled turn on the ground. The ground loop dynamics led to the right main landing gear leg shearing off and substantial damage to the right wing. The pilot exited the aircraft unharmed.
Damage Assessment
The aircraft sustained substantial damage to the right landing gear leg (sheared off) and the right wing. No other damage was reported.
GPIAAF Findings
The GPIAAF (Portuguese aviation safety investigation body) commented that the event's boundaries suggest piloting actions and techniques played a major role in the loss of directional control during landing. Deficient piloting technique due to lack of flight experience in a tailwheel aircraft was cited as a factor, leading to the initiation of ground loop dynamics and the consequent overload failure of the right landing gear leg.
The operator had been involved in a previous safety event on May 31, 2021, with the same type of aircraft, where operator manuals and procedures were found inadequate for ensuring pilot flight training conditions.