What happened
During a flight inspection mission at Terrace Airport, a Canadair CL-600-2A12 Challenger, registered as NAVCAN 200, was performing a landing on runway 33. As the aircraft approached the runway, a thin layer of fog reduced visibility. At the same time, an airport maintenance vehicle, Staff 61, was operating on the runway to inspect snow residue.
The vehicle operator had stopped to collect small pieces of snow and was approximately 10 feet from the vehicle when the sound of a jet engine prompted him to move. He reversed the vehicle toward the edge of the runway, but the aircraft passed the vehicle's position just as the operator reached the runway boundary. The pilot of the Canadair CL-600-2A12 Challenger reported seeing the vehicle at the edge of the runway only after entering the fog.
The investigation
The investigation focused on the communication gap between the flight service station (FSS) and the ground traffic. While the FSS specialist had authorized Staff 61 to enter the work area, the specialist was engaged in a telephone conversation with a refueling company at the time of the landing. This distraction, combined with the fact that the vehicle and the aircraft were operating on different radio frequencies, meant that the pilot was never notified of the vehicle's presence on the active runway.
Investigators also examined the visibility conditions, noting that a shallow fog bank obscured the northern half of the runway. Furthermore, the investigation looked into the lack of routine position reports required from vehicles in that specific work area, which meant the specialist had no recent radio contact to remind them of the vehicle's location.
Findings
- The FSS specialist failed to notify the pilot of NAVCAN 200 that a vehicle was operating on the runway.
- Fog obscured the vehicle from both the FSS specialist and the flight crew.
- The aircraft and the vehicle were using different radio frequencies, preventing mutual awareness.
- The absence of an active warning system or routine movement reports from the vehicle operator contributed to the loss of situational awareness.
- The specialist's attention was diverted by a request to contact a refueling company during the landing sequence.