What happened
On December 26, 2011, a BAE146-200, registration G-ZAPN, operated by Titan Airways, was taxiing to the Transit Parking area at Sion Airport (LSGS) following its arrival from London Stansted. While maneuvering toward its designated parking spot, the aircraft struck the southwest corner of the airport terminal building. The impact caused the tip of the aircraft's right wing to become wedged under the building's overhang. There were no injuries among the 54 passengers or the five crew members on board, and the passengers were able to disembark normally. The collision resulted in structural damage to the aircraft's wingtip, requiring a temporary replacement of the right winglet to facilitate the aircraft's return.
The investigation
The Swiss Transportation Safety Investigation Board (SUST) examined the communications between the crew and ground control, as well as the airport's infrastructure and procedures. The investigation focused on the taxi instructions provided by the ground controller and the guidance provided by the marshaller on the tarmac. Investigators also reviewed the ground markings at the Transit Parking area and the official aeronautical information publications (AIP) used by crews to navigate the airport.
Findings
- The primary cause of the accident was a collision between the aircraft and the terminal caused by the crew's error in following the taxi path.
- The ground controller failed to communicate the specific taxi route required to reach the parking area, despite a prior agreement to do so.
- The aircraft's right wingtip struck the terminal because the captain initiated a right turn prematurely, which contradicted the instructions being signaled by the marshaller.
- The ground markings at the Transit Parking area were confusing, specifically regarding the numbering of the parking lines.
- The official aeronautical documentation (AIP) lacked necessary details regarding the numbering of the taxiway paths at the parking area.
- The presence of only a single marshaller contributed to the incident, as an additional person could have potentially prevented the collision.
Safety action
Following the accident, several measures were implemented to improve safety at the Transit Parking area. The airport management coordinated with authorities to establish a more robust parking procedure. For Titan Airways flights, a wingman is now positioned at the entrance of the Transit Parking to monitor the clearance between the aircraft's right wing and the terminal. Additionally, the airport has undertaken physical changes, including the demolition of a nearby wooden structure to increase clearance, and is working on updating ground markings and publishing a more detailed Ground Movement Chart in the AIP.