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 characterized by successive deviations to the 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 maneuver, 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 at the time of the event. The investigation noted that the pilot had not operated this specific aircraft model since 201 and held a valid PPL(A) with a multi-engine qualification. Environmental conditions at the time of landing included a reported wind of 290/09kt, which produced an 8-knot right crosswind component for runway 17. While the aircraft showed signs of degradation due to potential inactivity or lack of preservation, investigators could not link the excursion to any mechanical failure.
Both crews emerged from the event uninjured. The collision caused significant damage to both aircraft: the Beechcraft 18 suffered a collapsed tail wheel, damage to the rear fuselage, vertical stabilizers, rudders, and the right landing gear braking system, while the Cessna 152 sustained substantial damage to its left wing and the cockpit area of the fuselage.
Findings
- The most probable cause of the accident was inadequate piloting technique during landing involving excessive directional correction (PIO).
- A contributing factor was the pilot's reduced proficiency with this specific aircraft model under the prevailing wind conditions.