What happened
On August 31, 2006, a Cessna 152, registration CS-AVD, operated by Escola de Aviação Aerocondor, was performing a solo flight training mission at Cascais Municipal Aerodrome. The flight was part of a training progression where an instructor had previously evaluated the student's proficiency during dual instruction earlier that day. After the instructor determined the student was ready for solo operations, the student began a series of solo circuits.
During the third circuit, the student pilot was unable to maintain directional control during the landing phase. The aircraft veered off the left side of runway 35, traveling approximately 30 meters before striking the concrete walls of the Ribeira das Marianas drainage ditch. The impact caused the propeller to bend, the engine cowling to sustain damage, and the main landing gear legs to break. The left wing tip also struck the opposite bank of the ditch, causing structural deformation and rupturing the fuel tank. Despite the fuel spill, no fire occurred, and the student pilot escaped the aircraft uninjured.
The investigation
The GPIAAF investigation examined the aircraft's maintenance records, the student's flight training history, and the physical evidence at the scene. Investigators noted that the aircraft's mechanical systems, including the brakes, were functioning correctly and that the left wheel was rotating freely, ruling out a brake lock-up. The investigation also reviewed the aerodrome's infrastructure, specifically the open drainage ditch located 25 meters from the runway edge.
Findings
- The primary cause of the accident was insufficient piloting technique leading to the loss of directional control during landing.
- A lack of flight activity continuity contributed to the student's diminished proficiency, as the student had flown only 2 hours and 55 hours in the 14 days preceding the accident.
- The presence of the uncovered, steep-sided drainage ditch significantly increased the severity of the excursion, transforming a simple runway departure into a major accident.
- The investigation noted that this was not an isolated incident, as three similar runway excursions involving loss of directional control had occurred at the same aerodrome in the two years prior.