What happened
On 1 July 2012, a SunExpress Boeing 737-800, registration TC-SNM, landed at Stockholm/Arlanda Airport after arriving from Turkey. Upon landing, the crew received taxi clearance to stand 19. While following the taxiway, the crew deviated from the published instructions, which required using entry ZH. Instead, the crew turned at entry ZK, based on the commander's previous experience at the airport.
As the aircraft attempted to maneuver behind a parked aircraft, a Boeing 737-800, registration TC-SUO, the left wingtip of TC-SNM struck the right elevator of the parked aircraft. The collision resulted in limited damage to both aircraft, and while the incident was serious, there were no injuries to any persons on board.
The investigation
The Swedish Accident Investigation Authority (SHK) examined the flight data, cockpit voice recordings, and air traffic control communications. The investigation focused on the crew's taxi route selection, the adequacy of the air traffic control clearance, and the cockpit dynamics during the maneuver. Investigators also reviewed the published taxiing instructions in the AIP-Sweden and the airline's operational procedures regarding uncertainty in aircraft positioning.
Findings
- The primary cause of the incident was that the crew misjudged the distance to the parked aircraft.
- The crew's pre-flight taxi briefing failed to include the correct, published route to stand 19.
- The aircraft was not maneuvered according to the established taxiway instructions.
- The commander held a strong conviction that the chosen route was correct and that sufficient clearance existed, which prevented the crew from stopping despite the co-pilot expressing concerns about the route and obstacle clearance.
- The crew relied on the presence of ground staff and the active transponder as a safety net, expecting air traffic control or ground personnel to alert them to any errors.
Safety action
SHK noted that while the air traffic controller's clearance met regulatory requirements, a more detailed instruction could have prevented the deviation. The investigation highlighted the risk of taxiing between entries ZH and ZK and suggested that clearer ground markings and more specific clearances would improve safety.