Incident Overview
On a dark night at Quebec City Airport, Quebec, a low-pressure system produced ceilings of 200 feet and visibility of 2,600 feet in fog. Runway 06 was in use for ILS approaches. Traffic was light, involving a Beechcraft 1900 (Bizex 954), a Dash 8 (AAQ125), and a Fokker 28 (ICN 1668) holding for departure. The control tower could not see runway 06 due to poor visibility, but had RAMP radar screens showing aircraft on approach. There was no ground radar. Five controllers were on duty: a controller-instructor, a controller trainee, a ground controller, a co-ordinator (not in the tower at the time), and an operations support specialist. No supervisor was present.
Sequence of Events
After the Beechcraft landed, the Fokker lined up on runway 06 while the Dash 8 was on final at seven nautical miles. The Beechcraft crew, unfamiliar with the airport, taxied slowly toward taxiway Alpha. While the Beechcraft was still on the runway and the Dash 8 was at three nautical miles, the controller trainee asked the Fokker to exit via taxiway Golf. However, another aircraft occupied Golf, so the Fokker headed for taxiway Hotel, 1,600 feet from the threshold, a maneuver confirmed by the controller trainee.
When the Dash 8 was at one nautical mile, the Beechcraft reported exiting onto taxiway Alpha. The controller trainee then cleared the Dash 8 to land at half a nautical mile out, with the Fokker approaching taxiway Hotel. Crossing the threshold at 100 feet above ground level, the Dash 8 pilot saw the Fokker's navigation lights still on the runway and executed a missed approach, flying over the Fokker at the usual ILS touchdown point.
Controller Actions and Factors
The controller trainee had 24 years of terminal control experience and was in initial airport control training, with normal progress. The controller-instructor considered him competent. The three controllers were alert and focused on the Beechcraft's progress. The original plan—Beechcraft land, Fokker take off, then Dash 8 land—was disrupted by the Beechcraft's slow exit due to unfamiliarity and fog. The revised plan had the Fokker exit quickly, but taxiway Golf was occupied. The Fokker crew specified they would taxi to Hotel and call when clear; the trainee confirmed but apparently did not fully assimilate the 1,600-foot distance and the time needed. As the Dash 8 was less than a minute from landing, the trainee, convinced the Fokker had exited, cleared the Dash 8 to land.
Findings and Cause
The Transportation Safety Board determined that due to poor processing of information, the Dash 8 was cleared to land while the Fokker was still on the runway. Reduced visibility was a contributing factor.