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 runway contact. Following a second touchdown, the aircraft entered a divergent dynamic characterized by successive deviations to the left and right. This resulted in a ground loop that sent the aircraft off the left side of the runway, rotating approximately 220 degrees from its original heading. During this excursion, the right wingtip of the Beechcraft 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 at the time of the event. The investigation noted that the pilot had not operated this specific aircraft model since 201 runway 17, which featured a 4° APAPI and a negative slope of -1.1%. At the time of landing, the wind was reported as 290/09kt, providing an 8-knot right crosswind component. While the Beechcraft 18 showed signs of degradation due to potential inactivity or lack of preservation, investigators could not link the runway excursion to any mechanical failure.
Findings
Both crews emerged from the event uninjured. The Beechcraft 18 sustained damage to the rear fuselage, vertical stabilizers, and rudders after the tail wheel collapsed upon striking the edge of the taxiway. The right landing gear braking system was also damaged by ground contact. The Cessna 152 sustained substantial damage to its left wing and the left side of the cockpit area.
Key contributing factors included the pilot's reduced proficiency with this specific aircraft model under the recorded wind conditions, noting that the pilot had not flown the type since 2018.