Accident Overview
On 19 October 1983, at 17:40 hours, a Piper PA-28-140, registration CS-AHZ, operated by Aero Clube de Portugal, departed from Cascais Aerodrome for a training and recreational flight. The aircraft carried a pilot and one passenger.
Aircraft and Crew
The single-engine aircraft was certified, equipped, and maintained in accordance with regulations. The pilot held a valid American Private Pilot License with a foreign license validity certificate, and had approximately 270 hours of total flying experience. The pilot was certified for the intended flight.
Sequence of Events
According to a witness, while flying low over the Serra de Sintra, the pilot observed a loss of engine power. The aircraft sank and the pilot did not have time to initiate a turn to avoid trees, colliding with them. The wind was light at the time of the occurrence.
Investigation and Findings
Post-accident examination of the aircraft revealed no anomalies in its systems or components that could have contributed to the accident. The engine was tested on another airframe and produced normal power at all regimes. The propeller blades showed signs of rotation at impact, indicating the engine was delivering power upon impact. Fuel was present in the tanks and the fuel system was unobstructed. The aircraft was found to be in an airworthy condition at the time of the accident.
The pilot, despite having limited experience, was properly certified. Weather conditions were CAVOK with light wind, though some turbulence was possible near the ridge. The pilot reported a loss of power, but no deficiency was found during tests.
Damage and Injuries
The aircraft was destroyed. The pilot was uninjured; the passenger suffered a leg fracture. Minor damage to forest trees at the Serra de Sintra was reported. Rescue was provided promptly by nearby witnesses using a private vehicle.
Conclusion
The probable cause was the execution of flight at such low altitude that the pilot did not have maneuvering space to avoid collision with trees, given that the area is not flat and the height of the trees is irregular.