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 aircraft 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 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.
Both crews were uninjured in the event. 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 also sustained damage from ground contact. The Cessna 125 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 aircraft components showed signs of degradation due to inactivity or lack of preservation, no mechanical failure was linked to the excursion. The pilot, a 57-year-old individual holding a PPL(A) with multi-engine qualification, 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, creating an 8-knot right crosswind component for runway 17.
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 reported wind conditions.