Incident Overview
A Canadair Limited CL-600-2A12 Challenger, operating as NAVCAN 200 with two pilots and one passenger, was on a flight inspection mission near Terrace Airport, British Columbia. At approximately 1118 Pacific standard time, while landing on runway 33, the aircraft encountered a white airport maintenance vehicle (Staff 61) that was on the runway. The aircraft had just entered a fog bank that reduced visibility to about one-quarter mile when the crew noted the vehicle at the side of the runway. The vehicle operator had backed off the runway edge just as the aircraft passed.
Sequence of Events
The flight service station (FSS) specialist had authorized Staff 61 to access work area 15/33 at 1111:17 for snow-clearing inspection. The vehicle operator stopped several times to pick up small pieces of snow that had fallen from a runway sweeper. During these stops, he left the vehicle door open and switched his radio to the rear speaker. At about 1116, NAVCAN 200 reported joining downwind for runway 33. The specialist provided wind advisory but did not relay that a vehicle was on the runway. The pilot later requested that the specialist contact the refuelling company; the specialist spent 35 seconds on the phone. At 1117:57, Staff 61 called the FSS, but the specialist did not answer immediately as he was completing the phone call. At 1118:03, the pilot reported a vehicle at the edge of the runway in the fog. The specialist then instructed Staff 61 to exit the runway, but the aircraft had already passed.
Weather and Visibility
The 1100 METAR reported calm wind, visibility 20 statute miles, a few clouds at 600 feet, and shallow fog in remarks. At the time of the occurrence, a low fog bank had developed over the northern half of runway 33. The FSS specialist could not see that area, and the vehicle was not visible to the specialist due to the fog. The aircraft crew reported that the airport was visible below but a thin layer of fog partially obscured the northern half of the runway. They had scanned the runway but did not spot the vehicle. The fog bank started at approximately half the runway length, and upon entering it, visibility dropped to about one-quarter mile.
Vehicle and Communications
Staff 61 was a white vehicle equipped with a functioning strobe light, but neither the crew nor the specialist recalled seeing it. According to Transport Canada publication TP 312, service vehicles should be yellow and have a flashing yellow light at night; the vehicle had a flashing white strobe, orange hazard lights, and white headlights. The vehicle operator heard the jet engine from about 10 feet away, ran to the vehicle, backed off the runway, and saw the aircraft pass about five seconds after hearing the engine. There had been no communication between the specialist and Staff 61 for over six minutes before the incident. The FSS specialist did not inform the pilot of the vehicle's presence at any point.
Procedures
The FSS at Terrace Airport provides airport advisory and vehicle control services. The vehicle control frequency is separate from the mandatory frequency (MF) used by aircraft. Snow-clearing vehicles in work area 15/33 have unrestricted access and are not required to give position reports. The specialist was responsible for both flight and vehicle services, and no team leader was present that day. Neither specialist had received a relief break in about four hours. The specialist commented that after landing, the aircraft disappeared into the fog.
Aftermath
The vehicle operator followed the aircraft to the ramp after the incident. The source does not state any injuries or damage.