What happened
On October 23, 2004, at approximately 14:20 UTC, a Cessna F150L, registration CS-AVI, operated by Aero Clube da Costa Verde, was conducting a local training flight at Espinho Aerodrome. The pilot was performing simulated engine-failure approaches to prepare for an upcoming proficiency check. After successfully completing three circuits on the right-hand side of the pattern, the pilot transitioned to a left-hand circuit for a fourth approach.
During the final approach to runway 18, the aircraft was configured with the engine at idle, carburetor heat on, and flaps retracted. As the aircraft crossed the breakwater and transitioned from land to sea, it encountered significant turbulence and windshear caused by the interaction of different air masses and the presence of coastal structures. The aircraft experienced a rapid loss of airspeed and altitude. Although the pilot attempted to recover by applying power, the aircraft failed to regain sufficient altitude and impacted the water approximately 5/50 meters from the runway threshold. The pilot and one passenger were able to exit the aircraft and swim to the beach unharmed. While the initial impact caused only minor damage, subsequent heavy surf destroyed the right wing, empennage, and engine cowlings, resulting in a total loss of the aircraft.
The investigation
The GPIAAF examined the aircraft's maintenance history, noting it had recently undergone a major inspection. The investigation confirmed that the engine and flight controls were fully operational and no mechanical failures contributed to the accident. Investigators also reviewed the aerodrome configuration, noting that due to local road access, only the northern portion of the runway was operational, which placed the final approach path directly over the sea. The investigation also assessed the meteorological conditions, which included strong winds of approximately 15 knots and heavy surf.
Findings
- The pilot's delayed corrective action to increase power and adjust the flight path after encountering atmospheric instability was the primary cause of the impact.
- The transition from land to sea during the left-hand circuit exposed the aircraft to complex windshear and turbulence created by the junction of different air masses and the coastal breakwater.
- The pilot was focused on maintaining the simulated engine-out profile and did not immediately apply power to counteract the sudden loss of energy.
- The aircraft's destruction was primarily caused by the force of the waves after the initial water landing.