What happened
On a flight from Toronto / Lester B. Pearson International Airport to Calgary International Airport, a Jetsgo DC-9-83, registration C-FRYH, experienced a runway excursion during an instrument landing system (ILS) approach to Runway 34. At approximately 1956 MST, the aircraft touched down roughly 80 feet to the left of the runway centerline.
Following the touchdown, the aircraft drifted left of the runway surface, traveling 1600 feet before the crew initiated a missed approach. During the excursion, the aircraft's left outer flap struck a hold short sign, and the left main landing gear subsequently destroyed another hold short sign. The aircraft was on the ground for approximately 11.5 seconds. The crew subsequently performed a second ILS approach and landed successfully at 2010 MST. There were no injuries among the 78 passengers and 6 crew members, though the aircraft sustained minor damage.
The investigation
The investigation examined the weather conditions, cockpit procedures, and the transition from instrument to visual flight. At the time of the first approach, the runway visual range (RVR) was 1400 feet, with visibility significantly reduced by light snow and freezing fog.
The crew was operating in accordance with Canadian Aviation Regulations, and both pilots were properly rested and licensed. The investigation noted that while the autopilot and auto throttles were engaged during the approach, the captain disconnected the autopilot at approximately 65 feet above the aerodrome elevation. At this moment, the aircraft entered a 10-degree left bank. The investigation also reviewed the effectiveness of the visual aids provided for a Category I approach under these specific RVR conditions.
Findings
- The primary cause of the excursion was insufficient visual cues during the landing phase, which prevented the pilots from accurately judging the aircraft's orientation relative to the runway.
- The transition from instrument to visual flight was compromised by a 10-degree left bank and reduced forward visibility.
- Environmental factors, such as freezing fog swirling around the aircraft, may have created illusions regarding the aircraft's movement.
- Current regulations allow for approaches and landings in low-visibility conditions, which increases the risk of an unsuccessful transition to visual flight when visual aids are inadequate.