What happened
On the morning of October 28, 2016, a serious near-miss occurred at Helsinki-Vantaa Airport (EFHK) during a period of high traffic volume. At the time, the airport was utilizing parallel runways 22L and 22R in independent operations.
At approximately 08:49, the aircraft SAS1706 was on its landing roll on runway 22L. Simultaneously, the aircraft FIN7PN was taxiing toward a holding point, requesting permission to cross runway 22L to reach holding point WD. The air traffic controller at the Tower East (TWR-E) workstation issued a conditional clearance for FIN7PN to cross runway 22L behind the landing SAS1706. However, the controller subsequently corrected the instruction, directing the aircraft to hold at point WG instead. At the moment the clearance was being processed, SAS1706 was still decelerating on the runway, approximately 100–150 meters from the intersection where FIN7PN was intended to cross.
The investigation
OTKES examined the local air traffic control (ATC) surveillance and monitoring systems, radio communications, and telephone recordings. The investigation also reviewed the operational manuals for Helsinki-Vastanta ATC and the safety management systems of the airport operator. The investigators analyzed the staffing levels at the time of the event, the technical systems in use—including the electronic strip system (eStrip) and the stopbar light system—and the workload of the controllers involved.
Findings
- The primary cause of the near-miss was the issuance of a runway crossing clearance while an aircraft was still occupying the runway.
- The controller was managing a high-density traffic situation, with multiple aircraft (including IBK602, FIN765V, and FIN4QA) all awaiting clearances to cross runway 22L.
- The controller's workload was increased by non-operational tasks, specifically handling telephone calls regarding the dispatch of weather observation balloons.
- There was no supervisor present at the workstation to manage these external communications, forcing the active controller to handle both traffic and administrative calls.
- While the controller did eventually correct the clearance to prevent the crossing, the initial instruction created a high-risk situation where the aircraft's path intersected with the landing aircraft's path.