What happened
On January 17, 1998, a Finnair DC-9-51, registration OH-LYP, was preparing for a scheduled passenger flight from Helsinki-Vantaa to Copenhagen. Earlier that day, the aircraft had experienced minor technical issues involving a pressure gauge and a lighting fault, which necessitated repairs and caused delays to the flight schedule.
In an effort to recover lost time, the flight crew proceeded with pushback and taxiing procedures rapidly. After receiving clearance to taxi via taxiway Kilo, the aircraft was instructed to hold at taxiway X (the holding point for runway 15/33). However, the crew mistakenly crossed runway 15, entering the taxiway leading toward runway 22. The tower controller noticed the deviation and alerted the crew that their clearance was only to the holding point. The captain realized the error as the aircraft was turning onto the runway but was unable to stop the aircraft before entering the active runway area. Fortunately, no other traffic was on the runway at that moment, and the aircraft was permitted to proceed with takeoff shortly after.
The investigation
The investigation examined the sequence of events, the cockpit environment, and the communication between the crew and air traffic control. Investigators reviewed radio transcripts, airport logs, and the technical status of the aircraft. The inquiry focused on why the crew deviated from their assigned taxi route and why the first officer failed to intervene when the boundary was crossed.
Findings
- The primary cause of the incursion was the captain's incorrect assumption regarding the taxi clearance boundaries.
- The crew was operating under significant time pressure due to the need to adhere to the flight schedule following morning technical delays.
- The first officer was heavily focused on performing checklist items (head-down work) and failed to monitor the aircraft's position or warn the captain of the deviation.
- The crew's desire to expedite the departure led to a narrowed situational awareness.
- While the radio frequency was relatively quiet, the crew's perception of low traffic volume contributed to a false sense of security.
- There were no injuries or damage to the aircraft or airport infrastructure.