What happened
An instrument flight rules (IFR) flight involving a Wildcountry Airways Ltd Chieftain was traveling from Red Lake, Ontario, to Atikokan via airway Amber 4. While cruising at 7,000 feet, the pilot identified another aircraft at the two o'clock position that appeared to be on a collision course. The pilot attempted to alert the other aircraft via the 126.7 MHz frequency, but no contact was made, necessitating immediate evasive maneuvers.
The second aircraft, a Fast Air Piper Navajo operating under visual flight rules (VFR) from Winnipeg to Sioux Lookout, was not observed by its pilot until the Chieftain had already begun its avoidance maneuver. Radar analysis later showed the aircraft were only approximately 200 feet apart vertically and a quarter-mile apart laterally at the point where their tracks crossed. The pilot of the Chieftain reported flying through the wake of the Navajo during the maneuver.
The investigation
The investigation focused on the altimeter settings, air traffic control (ATC) procedures, and pilot communications. It was determined that while both aircraft were in the altimeter setting region and required the Dryden setting of 30.08 inches of mercury, the pilot of the Fast Air Piper Navajo had failed to update his altimeter after departing Winnipeg, leaving it at 30.38 inches of mercury. This error caused the aircraft to fly at an actual altitude of approximately 7,200 feet instead of the intended 7,500 feet.
At the time of the incident, the Kenora Sector controller was managing both radar and data controller responsibilities alone. The investigation found that the controller had prioritized administrative data tasks over monitoring uncorrelated targets, which included the VFR-operating Navajo. Furthermore, the investigation examined the lack of communication, noting that the Navajo pilot was monitoring 122.8 MHz rather than the recommended 126.7 MHz frequency, and had not requested en route radar surveillance.
Findings
- The Fast Air Piper Navajo was flying approximately 300 feet lower than its indicated altitude because the pilot did not reset the altimeter to the nearest station's pressure setting.
- The vertical separation between the two aircraft was roughly 200 feet, which was 300 feet less than the required 500-foot minimum.
- The Kenora Sector controller was performing dual duties and prioritized data controller tasks over monitoring uncorrelated radar targets.
- The pilot of the Fast Air Piper Navajo did not request en route radar surveillance, which would have allowed for altitude verification.
- The pilot of the Fast Air Piper Navajo was not monitoring the 126.7 MHz frequency, and guidance for VFR pilots regarding this frequency is not widely publicized.
- The pilot of the Wildcountry Airways Ltd Chieftain maintained a proper visual lookout and successfully executed evasive action.