What happened
On August 6, 2000, a Cessna 152, registration CS-AUK, departed Cascais Aerodrome at 15:54 UTC for a private recreational flight. The aircraft, carrying a pilot and one passenger, was flying under Visual Flight Rules (VFR) on a route from Tires to Cabo Espichel, continuing toward Tróia and returning to Cascais.
After overflying Cabo Espichel, the pilot requested and received authorization from Lisbon Flight Information Service (FIS) to proceed along the coastline toward Tróia at an altitude of 500 feet. At approximately 16:20, radar and radio contact with the aircraft was lost near the Barbas de Cavalo area in Portinho da Arrábida. Witnesses on nearby vessels observed the aircraft strike the water and sink rapidly. Eyewitness accounts described the aircraft banking heavily to the left and right before plunging into the sea. While one witness noted the engine appeared to be producing low power, others could not confirm the engine' and status.
The investigation
The investigation involved a search operation by the Portuguese Navy vessel NRP Andrómeda. On August 11, 2000, wreckage and the bodies of the two fatalities were located at a depth of approximately 50 meters. Remote Operated Vehicle (ROV) footage revealed that the aircraft was resting on its landing gear, with significant structural damage, including a broken tail and a broken right wing. The engine cowling had been stripped, and the propeller showed deformation consistent with the engine being operational at the time of impact.
Investigators examined meteorological data from the Setúbal station, which recorded high temperatures (exceeding 35°C) and significant wind gusts. The investigation also considered the terrain of the Serra da Arrábida, which is known to cause radar and radio shadows at low altitudes.
Findings
- The aircraft was flying at 500 feet, which was within the legal limits for VFR flight in that area.
- Meteorological conditions included high temperatures and wind gusts that likely contributed to strong turbulence and potential wind shear or downdrafts caused by the local topography.
- The physical state of the wreckage, specifically the deformation of the propeller and the impact damage to the wing and door, suggests a high rate of descent and a high-velocity impact with the water.
- Medical examinations confirmed that neither the pilot nor the passenger were under the influence of alcohol or drugs, and there was no evidence of sudden physical incapacitation of the pilot.