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 cause a bounce on the first contact. 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 excursion, 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 examined the aircraft condition, crew data, and environmental factors present during 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 cloudy sky and a wind from 290 degrees at 09 knots, which produced an 8-knot right crosswind component for runway 17. 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
- The primary cause of the event was inadequate piloting technique during landing, specifically involving excessive directional correction (PIO).
- A contributing factor was the pilot's reduced proficiency with this specific aircraft model under the reported wind conditions.
- The ground loop caused the Beechcraft 18 tail wheel to collapse upon striking the edge of the taxiway, leading to damage to the rear fuselage, vertical stabilizers, and rudders.
- The collision caused substantial damage to the cockpit area and left wing of the Cessna 152.
- Both crews emerged from the event uninjured.