What happened
On January 7, 2005, at approximately 13:30, a Stinson L-5 Sentinel, registration I-AEEG, was engaged in glider towing operations at Padova Airport. Following a series of successful flights, the pilot performed the first landing of a second flight sequence on the grass landing strip. Immediately after touchdown, the aircraft began to yaw, likely due to surface irregularities on the grass. In an attempt to correct the directional deviation, the pilot applied the brakes abruptly and excessively. This sudden braking action caused the aircraft to pitch forward and overturn.
There were no fatalities and the pilot escaped without injury. The aircraft sustained damage to the propeller, the left wing semi-span, and the vertical stabilizer.
The investigation
The ANSV investigation examined the aircraft's mechanical configuration and the pilot's actions. The investigation noted that the Stinson L-5 Sentinel is a taildragger-type aircraft, meaning its center of gravity is located behind the main landing gear. This configuration makes the aircraft inherently susceptible to nose-over accidents if braking forces are applied too aggressively during ground operations.
The investigators reviewed the pilot's flight experience, noting that while the total flight time was relatively low, the pilot was experienced in this specific type and was performing routine training operations. Meteorological conditions were clear with calm winds, and the investigation determined that weather played no role in the event.
Findings
- The primary cause of the accident was the inappropriate braking technique used by the pilot, which was not suited to the aircraft's characteristics, the ground surface, or the taxiing speed.
- The use of differential braking to correct a yawing motion, combined with excessive braking force, created a rotational moment around the main gear axis that lifted the tail and led to the overturn.