What happened
On September 8, 2016, at Warsaw Chopin Airport (EPWA), an Embraer 190-100 aircraft, registration OH-LKM, was being prepared for flight AY 744 from Warsaw to Helsinki. Following passenger boarding and loading at stand 22, a pushback procedure was initiated using a SCHOPF F 206 tug and a standard towbar.
Upon reaching taxiway M at approximately 19:00, the ground crew encountered difficulty disconnecting the towbar from the tug, specifically noting that the towbar's locking pin could not be removed. To assist with the disconnection, the tug operator exited the vehicle cabin to aid the ground worker.
After several attempts, the locking pin was successfully removed, causing the towbar to drop onto the apron. However, because the operator had failed to engage the parking brake before exiting the vehicle, the tug began to roll due to the local terrain gradient and a lack of resistance. The moving tug struck the nose of the Emlaner 190-100, resulting in a crack in the aircraft's nose cowling.
The investigation
The PKBWL investigation examined the ground handling procedures and the actions of the personnel involved. The investigation confirmed that the operators were properly qualified and were not under the influence of alcohol or drugs. Weather conditions at the time of the incident were found to have no impact on the event.
Findings
- The primary cause of the incident was the failure to follow established procedures, specifically the failure to secure the vehicle.
- The tug operator exited the vehicle without engaging the parking brake.
- The slope of the apron and the lack of a physical obstruction allowed the tug to move freely once the towbar was disconnected.