What happened
On July 12, 2013, an Aviat A-1B (Husky), registration F-GUSK, departed from a private airfield in La Cerdanya for Reus Airport. The flight was operated as a private general aviation mission with the pilot as the sole occupant. Upon approaching Reus, the pilot received authorization to land on runway 07, with wind information provided as 160°/8 kt.
While the approach and initial touchdown were normal, the aircraft lost control during the landing roll. The aircraft began a sharp turn to the right, exiting the runway. During this excursion, the left main landing gear leg collapsed, causing the left wingtip and the left elevator to impact the ground. The aircraft came to a stop on the right side of the runway safety area. The incident forced a temporary suspension of operations at Reus Airport, affecting the departures of an Airbus A-de 320 and a flight school aircraft, until the aircraft was towed away 20 minutes later.
The investigation
The investigation examined the aircraft's mechanical condition, the pilot's experience, and the meteorological conditions at the time of the accident. The Aviat A-1B (Husky) had undergone a 100-hour maintenance inspection earlier that year. The pilot was an experienced aviator with 1,460 total flight hours, including 100 hours in this specific type, and had received specialized training in tailwheel operations and mountain flying.
Meteorological data from the period surrounding the accident showed highly variable wind directions. At the time of the landing, the wind was shifting significantly, ranging from nearly a headwind to a tailwind component. The pilot reported that during the final approach, the ground speed was approximately 10 knots higher than the airspeed, indicating a tailwind component. The pilot also noted that the touchdown was somewhat abrupt, causing the tail to lift and the aircraft to begin deviating to the right.
Findings
- The aircraft's tailwheel configuration makes it naturally susceptible to ground loops (swerving) when subjected to crosswinds or shifting wind directions.
- During the approach, the pilot likely applied right rudder to compensate for a wind component coming from the right.
- Upon touchdown, the combination of wind force on the vertical stabilizer and the friction from the landing gear created a torque that induced a yaw to the right.
- The loss of control was caused by a delayed rudder correction during the transition from flight to ground roll, which allowed the yaw to escalate into an uncontrollable ground loop.
- The variable wind conditions, including a tailwind component and shifting directions, significantly complicated the landing maneuver.