Event Overview
On 25 May 2016, at approximately 09:25 UTC, a ground collision occurred on the apron of Leoš Janáček Ostrava Airport (LLJO) between a Zlín Z 43 (registration OK-XOD) and a Cessna C 152 (registration OK-LFA). The Zlín was being prepared for a training flight; the Cessna was parked and unoccupied. No injuries were reported among the Zlín's crew or other persons.
Circumstances
The Zlín had been parked on the apron of operator A, oriented with its nose toward the old control tower, parallel to the adjacent hangar doors. The aircraft was not chocked. The student pilot, aged 22, was undergoing training for a PPL(A) license. The instructor, believing the student was ready for solo flight, instructed the student to board the aircraft, perform a cockpit check, start the engine, and warm it up. The instructor stood approximately 5 meters away, also attending to another student.
Upon starting, the engine immediately accelerated to high rpm, and the Zlín began moving forward. The student did not stop the movement. The aircraft traveled straight for about 100–120 meters across the apron, toward the old control tower, and struck the parked Cessna. The impact occurred with the Zlín's front section and left wing striking the rear of the Cessna. The rotating propeller separated the Cessna's rear fuselage. The Zlín then rotated around the Cessna's front, causing further damage. The Cessna was displaced approximately 12–15 meters forward and yawed 45° left. After the collision, airport ground personnel helped the student exit the Zlín.
Aircraft Information
The Zlín Z 43 (OK-XOD, serial 0108) is a four-seat, low-wing, single-engine monoplane with a fixed tricycle landing gear. It was powered by an Avia M 337AK engine and had a total of 2,883 flight hours. The Cessna C 152 (OK-LFA, serial 15284293) is a two-seat, high-wing, single-engine monoplane with a fixed tricycle landing gear, powered by a Lycoming engine. It had accumulated 8,697 flight hours.
Investigation Findings
A technical inspection of the Zlín after the accident found no functional deficiencies in the engine controls, brakes, ignition switch, or seat lock. The Zlín's engine control mechanism, when the lock is released, has a tendency to move forward, increasing engine rpm. The instructor stated that he had personally flown the aircraft the previous day and, when shutting down, had released the throttle lock and briefly increased rpm before pulling the lever back while switching off the ignition.
The student reported that after starting, the engine went to high rpm and the aircraft accelerated. He attempted to apply the brakes but they did not respond. The investigation determined that the student did not check the throttle position before starting and did not depress the brake pedals with his feet. The apron operations did not have a signalist active at the time of the engine start, as required by the apron operating manual, though the manual did not specify conditions for signalist activation.
Both aircraft were parked in accordance with the respective apron operating procedures.