Incident Overview
On 8 May 2023, at approximately 19:15 local time, a SAAB 340A aircraft, registration HA-TAD, operated by Fleet Air International Kft., was involved in a serious incident at Zagreb Airport Franjo Tuđman. The aircraft had just completed a flight from Sarajevo Airport and was in the process of parking when it began moving forward uncontrollably, colliding with a car and a van. No injuries were sustained by the three crew members or the single occupant of the vehicles.
Sequence of Events
The flight from Sarajevo to Zagreb was uneventful, with all parameters in the green. The aircraft landed on runway 04 at 17:00 local time and taxied to parking position W4 via taxiways C and F. During the turn onto taxiway F at 17:02, the crew heard a persistent unusual noise from the hydraulic pump. They checked the pressure and fluid level; pressure was normal but the fluid level was lower than usual. Following the abnormal checklist, they decided to shut down the hydraulic pump.
Upon reaching parking position W4 at 17:04, the crew observed a lower hydraulic fluid level but noted that the main and auxiliary hydraulic accumulators were pressurized, which the checklist indicated was sufficient for a safe stop. At 17:05, after stopping the aircraft, a yellow hydraulic warning appeared on the central warning panel. The crew signaled to the marshaller that the parking brake was set and requested wheel chocks. However, the marshaller looked away and entered his vehicle, leading to confusion.
While the crew reviewed the hydraulic system status and began shutting down the engines, the aircraft started moving forward uncontrollably. Repeated attempts to brake and steer were unsuccessful. The aircraft came to a stop only after its nose landing gear struck a parked vehicle. Approximately one hour later, the crew underwent a breathalyzer test, which confirmed no alcohol consumption.
Damage
The collision caused the nose landing gear doors to bend and crack at several points. The fiberglass fairing on the left side of the nose fuselage above the nose gear was fractured, and a hydraulic line protected by that fairing was damaged, leading to fluid leakage. The aircraft also sustained damage to its taxi light. The two ground vehicles involved suffered partial damage.
Cause
The incident occurred due to loss of pressure in the aircraft's hydraulic brake system, which resulted from the pilots' decision to turn off the hydraulic pump.