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 such high speed and an improper attitude that it bounced on the first contact. 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 original 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.
Both crews emerged from the event uninjured. The Beechcraft 18 sustained damage to its rear fuselage, vertical stabilizers, and rudders after the tail wheel collapsed upon striking the edge of the taxiway. The Cessna 152 suffered substantial damage to its left wing and the cockpit area of the fuselage.
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 components of the Beechcraft 18 showed signs of degradation likely due to inactivity or lack of preservation, no mechanical failure was identified as the cause of the excursion.
At the time of the landing, the wind was reported as 290/09kt, providing an 8-knot right crosswind component for runway 17. The pilot, a 57-year-old holder of a PPL(A) with multi-engine qualification, had not operated this specific aircraft model since 2018.