What happened
On May 24, 2023, an instructor and a student pilot prepared for a PPL(A) training flight involving route navigation. After checking fuel and oil levels, the aircraft, an AT-3 R-100 with registration SP-GET, was moved to a grass parking area. The instructor, believing the student was sufficiently experienced, tasked the student with performing the preflight inspection independently while the instructor completed flight planning and weather briefing paperwork.
At approximately 18:00 LMT, the student started the engine and taxied to the threshold of runway 3/2R. Following a successful engine run-up, the student commenced the takeoff roll. Shortly after reaching an altitude of a few meters, the aircraft began experiencing intense airframe vibrations. The instructor immediately took control of the aircraft and performed an emergency landing straight ahead.
Upon exiting the aircraft, the crew inspected the airframe and discovered that the propeller blade tips were damaged. A subsequent inspection of the runway revealed a damaged strut lock located approximately 400 meters from the aircraft's position. No damage to the airframe was identified.
The investigation
The PKBWL investigation focused on the sequence of the preflight inspection and the presence of foreign objects on the runway. The investigation established that the propeller damage was a direct result of an object left on the aircraft during the takeoff roll.
Findings
- The primary cause of the incident was the improper execution of the preflight inspection, specifically the failure to remove the strut lock from the front landing gear strut.
- A contributing factor was that the student pilot performed the preflight inspection without direct supervision from the instructor.