What happened
On July 12, 2021, at Jelenica Góra (EPJG) airport, a Jak 12 M, registration SP-AAM, was performing training flights under the supervision of an instructor. Following the completion of four training circuits, the pilot began taxiing toward the parking area in front of a hangar. As the aircraft reached the edge of the parking apron, the pilot initiated a right turn to position the aircraft facing away from the hangar.
During this maneuver, the pilot received a radio command to stop. In an attempt to decelerate, the pilot applied pressure to the rudder pedals. Because the aircraft failed to slow down, the pilot proceeded to switch off the magnetos. However, due to the aircraft's momentum, the still-rotating propeller struck the horizontal stabilizer of a parked Cessna 150, causing damage to both the propeller paint and the Cessna's tail section. No injuries were reported.
The investigation
The PKBWL investigation focused on the pilot's taxiing techniques and the mechanical operation of the aircraft's braking system. The investigation established that the pilot had limited experience with the Jak 12 M, having completed only 20 flights in this specific type. The investigation also examined the cockpit visibility constraints inherent to the aircraft's design during taxiing maneuvers.
Findings
- The pilot utilized an ineffective braking method because they attempted to use the rudder pedals to stop the aircraft, a technique learned from previous experience in Cessna 150 and PZL 104 Wilga aircraft, which utilize pedal-operated brakes. In the Jak 12 M, wheel brakes are operated via a lever on the control stick.
- The pilot failed to employ proper taxiing techniques for a taildragger aircraft, such as the "S-turn" method, which is necessary to maintain visibility of the area ahead due to the limited forward view from the cockpit.
- Limited visibility from the cockpit during taxiing contributed to the pilot's failure to notice the parked aircraft.