What happened
On January 14, 2004, at Rovaniemi Airport, a serious runway incursion occurred between a departing BAe Hawk MK 51A and a Boeing F-18C Hornet taxiing across the active runway. The incident took place during twilight hours under instrument meteorological conditions (IMC), with light snow and low cloud cover. Due to slippery runway conditions, all military aircraft were utilizing the full length of the runway for takeoffs.
A formation of three Hawks (G31) had been cleared to taxi and take off from runway 03 to runway 21. Simultaneously, a pair of Hornets (O71) was cleared to taxi across runway 21. The air traffic controller, believing the Hawks had all departed, cleared the second Hornet, O72, to cross the runway. However, the third aircraft in the Hawk formation, G33, was just beginning its takeoff roll.
The pilot of G33 noticed the crossing Hornet and immediately aborted the takeoff. Simultaneously, the pilot of O72 spotted the approaching Hawk and increased taxi speed to clear the runway. No collision occurred.
The investigation
The investigation focused on the controller's actions, the visibility conditions, and the pilots' communications. Investigators established that the controller had instructed the first Hornet to hold at position Juliet but cleared the second Hornet to cross the runway after observing the runway appeared empty. The investigation found that the controller was monitoring the departing aircraft "from the corner of his eye" rather than counting them.
Furthermore, the investigation examined the visibility of the aircraft. The slippery runway caused the G33 pilot to experience a delay in the takeoff roll, which was not reported to the tower. Additionally, the investigation revealed that a bulb in the taxi/approach light of the G33 was inoperative, significantly reducing the aircraft's visibility against the dark background.
Findings
- The primary cause was the controller granting clearance to the Hornet to cross the runway without verifying that all aircraft in the departing formation had actually taken off.
- The controller failed to count the number of departing aircraft and did not sufficiently ensure the runway was clear.
- The pilot of G33 did not inform the tower of a takeoff delay caused by the slippery runway, which extended the interval between aircraft by approximately 25 seconds.
- The visibility of the departing G33 was severely impaired because its taxi/approach light was inoperative, making it nearly impossible to spot visually against the dark, snowy background.
- The pilot of G33 was focused on managing the aircraft during a slide on the slippery surface and failed to process the crossing clearance issued to the Hornet.