What happened
On the morning of October 12, 2000, a runway incursion occurred at Helsinki-Vantaa Airport during a period of single-runway operations due to wind conditions. An SAS MD-81 (registration OY-KHN), operating flight SK700, had recently landed on runway 15 and was in the process of vacating the runway via taxiway YF. Simultaneously, a Finnair MD-83 (registration OH-LMU), operating flight FIN841Q, was positioned at the runway 15 holding point and received takeoff clearance from the tower.
As the Finnair aircraft began its takeoff roll, the flight crew noticed at approximately 140 knots (V1 phase) that the SAS aircraft was not clear of the runway area. Instead, the OY-KHN was stationary on taxiway YF, positioned at the holding point facing the runway. The aircraft was waiting for a Finnish Air Force Fokker 27 (callsign H22) to pass. The crew of the departing OH-LMU determined they could safely pass the stationary aircraft without aborting the takeoff.
The investigation
The investigation examined air traffic control (ATC) radio communications, ground controller instructions, and the physical layout of the airport. Investigators reviewed the coordination between the Tower and Ground controllers, as well as the training protocols for local controllers. The investigation also looked into the structural limitations of the taxiway intersections, noting that the distance between runway 15/33 and taxiway Y is too short to accommodate large aircraft like the MD-80 series without obstructing traffic.
Findings
- The primary cause of the incident was the ground controller's error in determining the taxi sequence, which forced the SAS aircraft to wait on taxiway YF, thereby obstructing the runway.
- The tower controller's attention shifted to the departing Finnair aircraft immediately after issuing clearance, resulting in a failure to monitor the continued movement of the arriving SAS aircraft.
- The ground controller overestimated the speed of the approaching Fokker 27, leading to a taxi instruction that required the OY-KHN to stop in a sensitive area.
- The ground controller failed to notify the tower controller that the SAS aircraft was stationary on the runway area due to the waiting sequence.
- The airport's physical configuration makes it difficult for MD-80 series aircraft to hold on certain taxiways without interfering with runway 15/33 operations.
Safety action
It is recommended that the Finnish Aeronautical Handbook be updated with more precise instructions regarding the priority of aircraft exiting runways at Helsinki-Vantaa to prevent similar obstructions.