Incident Overview
On 25 May 2019, at Gliwice Airport (EPGL), the crew of an AN-2 aircraft was performing skydiving flights. After landing following the third flight, around 13:07 local time, the crew requested permission to taxi to the fuel station to refuel. The aircraft moved from the runway via the taxiway without issues. However, after completing a 90-degree turn from the taxiway onto the apron in front of the fuel station, the aircraft commander, despite applying brakes, observed that the aircraft continued to change direction. He ordered the second pilot to brake. The second pilot applied brakes, but the aircraft kept rolling towards parked trucks. He then shut down the engine. The aircraft struck the spoiler of a truck's cab with the left upper wingtip and came to a stop.
Sequence of Events
The collision caused denting of the wingtip, damage to the fairing, and the light on the truck's cab. The crew were uninjured. The airport notified the State Commission on Aircraft Accident Investigation (PKBWL) and the police, who performed a breathalyzer test on the crew; results were 0.00 mg/L alcohol. Post-collision checks found the aircraft's pneumatic system pressure to be normal at 40 atm. The aircraft was pushed to the grass area, and after engine start, control and brake system operation were verified to be normal.
Investigation Findings
The operator's investigation determined that the crew held valid qualifications, the aircraft had necessary technical documentation and insurance, and no crew injuries occurred. The wingtip, fairing, and truck light sustained minor damage. The investigation did not identify a cause for the brake system malfunction.
Probable Cause
The probable cause of the incident was a temporary malfunction of the aircraft's pneumatic brake system.