What happened
On a flight from Abbotsford to Vancouver, a Convair 580, operating under the call sign REGS 33, was cruising at 4,000 feet above sea level. Simultaneously, a Canadian Regional Airlines de HavHDill DHC-8, flight CDR 1255, departed Vancouver International Airport for Victoria, climbing to 4,000 feet.
At 16:43 PST, the Vancouver departure controller identified a conflict between the two aircraft. Although the controller issued immediate instructions for the REGS 33 to turn left and for the CDR 1255 to descend to 3,000 feet, the separation between the aircraft had already breached safety minimums. The aircraft were reduced to a horizontal distance of 0.75 nautical miles and a vertical distance of only 400 feet. Because both crews were operating in visual meteorological conditions and had each other in sight, there was no risk of collision.
The investigation
The investigation examined the controller's workload, the use of the "REGS" call sign, and the accuracy of the radar data. It was noted that the REGS 33 flight was conducting a pilot proficiency check with a Transport Canada inspector in the jump seat. The controller, who was managing a heavy workload involving several other aircraft and weather-related re-routings, had failed to check the speed display in the aircraft data block.
Findings
- The controller's separation strategy was based on the incorrect assumption that the Convair 580 was a much slower aircraft than its actual speed.
- The controller associated the "REGS" call sign with smaller, slower commuter aircraft rather than the faster Convair 580.
- The controller did not observe the actual airspeed indicated on the radar data block or the flight data strip.
- The controller's attention was likely channelized by the need to manage a departure from Boundary Bay and a separate Canadian Regional flight encountering bad weather.