What happened
During an approach and landing at Cascais aerodrome, a Beechcraft 18 experienced a series of uncontrolled movements on the runway. The aircraft touched down with sufficient speed and attitude to bounce on its first contact with the runway. Following a second touchdown, the aircraft entered a divergent dynamic, oscillating left and right. This sequence resulted in a runway excursion to the left, where the aircraft performed a ground loop, rotating approximately 220 degrees from its initial heading. During this excursion, the right wingtip of the Beechcraft 18 struck a Cessna 152 that was holding on the taxiway awaiting takeoff for an instructional flight.
The investigation
The GPIAAF investigation examined the aircraft condition, crew data, and environmental factors present during the event. The investigation noted that the pilot had not operated this specific aircraft model since 2018. Environmental conditions at the time of landing included a cloudy sky and a wind from 290 degrees at 09 knots, which produced an 8-knot right crosswind component for runway 17.
Regarding the aircraft, the investigation found that while some components showed signs of degradation likely due to inactivity or lack of preservation, no mechanical failure was linked to the excursion. The impact caused the Beechcraft 18's tail wheel to collapse upon striking the edge of the taxiway, damaging the rear fuselage, vertical stabilizers, and rudders. The right landing gear braking system also sustained damage from ground contact. The Cessna 152 sustained substantial damage to its left wing and the left side of the cockpit area. Both crews were uninjured.
Findings
- The most probable cause of the accident was inadequate piloting technique during landing characterized by excessive directional correction (PIO).
- A contributing factor was the pilot's reduced proficiency with this specific aircraft model under the reported wind conditions.