What happened
During an approach and landing at Cascais aerodrome, a Beechcraft 18 touched down with excessive speed and an improper aircraft attitude, causing the plane to bounce on the first contact with the runway. Following a second touchdown, the aircraft entered a divergent dynamic characterized by successive deviations to the left and right. This sequence resulted in a ground loop, during which the aircraft rotated approximately 220 degrees from its original heading and exited the runway onto the left shoulder.
During the excursion, the aircraft's right wing tip struck a Cessna 152 that was holding on the taxiway awaiting takeoff for an instructional flight. The impact caused the Beechcraft 18's tail wheel to collapse upon striking the edge of the taxiway, leading to damage to the rear fuselage, vertical stabilizers, and rudders. The Cessna 152 sustained substantial damage to its left wing and the cockpit area of the fuselage. Both crews were uninjured.
The investigation
The GPIAAF investigation examined the aircraft's condition, the environmental factors, and the pilot's recent flight history. The investigation noted that while some aircraft components showed signs of degradation due to inactivity or lack of preservation, no mechanical failure was linked to the runway excursion.
Environmental data indicated a wind of 290/09kt at the time of landing, which produced an 8-knot right crosswind component for runway 17. The investigation also noted that the pilot had not operated this specific aircraft model since 2018.