What happened
On September 23, 2005, a Boeing MD-11, registration PH-KCG, was cleared for departure from Amsterdam Schiphol Airport. After receiving instructions to line up on runway 24, the flight crew was cleared for take-off. During the aircraft's take-off roll, a bird control vehicle, identified by the call sign 'Kievit 1', entered the active runway. The vehicle crossed the runway at the intersection with taxiway Sierra, passing in front of the departing aircraft. While the incident was a serious near-miss, there were no injuries and no damage to the aircraft or the vehicle.
The investigation
The Dutch Safety Board investigated the incident, examining air traffic control communications, vehicle movement, and airport procedures. The investigation focused on why the vehicle was granted clearance to cross the runway while an aircraft was already in its take-off phase. Investigators reviewed the radio transmissions between the tower assistant and the bird controller, as well as the physical layout of the intersection and the functionality of the stop bars at the taxiway.
Findings
Several contributing factors led to the runway incursion:
- The tower assistant granted clearance to the vehicle based on an incorrect assumption regarding its position. The assistant expected the vehicle to be at the northern end of the taxiway and approved the request believing the vehicle intended to drive south, rather than cross the runway.
- Radio communication interference and poor signal quality on the vehicle's primary radio caused the bird controller to be distracted and potentially led to an imprecise request.
- The vehicle's path was such that it bypassed the active stop bar, meaning the safety mechanism failed to prevent the crossing.
- There was a lack of mandatory visual verification procedures for vehicles crossing runways at that specific location.
- The use of non-standard call signs contributed to potential confusion during radio transmissions.
Safety action
Following the investigation, several safety improvements were identified and implemented, including:
- Renaming taxiway Sierra to 'Quebec' to prevent confusion between intersections and runway crossings.
- Recommendations to minimize runway crossings by guiding vehicles via inspection tracks or tunnels.
- Efforts to improve radio equipment quality and reduce the workload of personnel monitoring multiple frequencies.
- Proposals to enhance the protection of all runway access points with additional signaling or stop bars.