What happened
On December 14, 1974, at approximately 16:10 local time, a Cessna 177 Cardinal (CS-AKD) belonging to the Aeroclube da Costa Verde was conducting a local sightseeing flight over Porto with three passengers. The aircraft returned to Espinho Aerodrome for landing on Runway 18 under clear weather conditions (CAVOK).
During the final approach, the pilot observed a cyclist crossing the runway. He executed a go-around to avoid the cyclist. Upon initiating the second approach, the pilot noticed a grey van emerging from the right side of the service road near the runway threshold. Instinctively pulling back on the controls to avoid a collision with the vehicle, the aircraft entered a stall at low altitude. The nose gear collapsed upon impact with the ground, causing the aircraft to veer off the asphalt. The pilot managed to keep the nose up to prevent a catastrophic capsize, though the aircraft sustained significant damage.
The investigation
The GPIAAF investigated the accident involving CS-AKD. The aircraft was a 1968 Cessna 177 Cardinal with 1,202 total flight hours. The pilot, aged 46, held a Private Pilot License and had flown the Cessna 177 in instruction or adaptation phases. He had 454.5 hours of visual flight time and 211 landings.
The aircraft was found to be airworthy prior to the incident. The maintenance report indicated that the nose gear was torn from its attachment plate, the propeller blades were bent inward beyond recovery limits, and the carburetor was severed from the engine mount due to the upward force of the gear collapse. The pilot reported no injuries, nor did the three passengers.
Findings
The primary cause was the collision with a ground vehicle on the active runway area, which forced an emergency maneuver at low altitude. Contributing factors included:
- Pilot Error: The pilot reacted precipitously by pulling back on the controls without managing engine power, leading to a stall and subsequent nose gear collapse.
- Aerodrome Safety: The Espinho Aerodrome lacked adequate security measures to prevent unauthorized or unmonitored vehicle movements in maneuvering areas. The presence of a van crossing the runway highlighted a critical safety gap for aeroclubs with less experienced users.
The GPIAAF concluded that while the pilot's reaction was understandable given the sudden threat, it resulted in a loss of control due to insufficient airspeed management. The investigation also noted that the lack of vehicle monitoring at the aerodrome was a significant hazard.
Safety action
The GPIAAF recommended an inquiry into the safety conditions of Espinho Aerodrome to ensure it met minimum security standards for opening traffic. They emphasized the need for better monitoring of vehicle movements in maneuvering areas, particularly on weekends when activity is high. Additionally, they suggested that the pilot undergo a proficiency check focusing on slow flight and stall recovery techniques.