What happened
At approximately 1315 Pacific daylight time, a Helijet International Incorporated Sikorsky S-76A helicopter, registration C-GHJL, was conducting an IFR med-evel flight from Victoria to Vancouver Harbour. While operating near Active Pass, the Victoria terminal controller cleared the crew to descend from 3000 to 2200 feet. Shortly after this clearance, the controller notified the helicopter crew of an approaching radar target that had previously gone undetected. The helicopter crew immediately observed a landing light directly ahead and performed an evasive maneuver to the right.
The opposing aircraft was a Harbour Air Ltd. de Havilland DHC-3 (Otter), registration C-FRNO, flying a VFR route from Vancouver Harbour to Victoria Harbour. The pilot of the C-FRNO had just been cleared through the Victoria Airport control zone and was leveling at 2500 feet. Although the pilot had not been notified of any conflicting traffic, he spotted the C-GHJL performing an evasive maneuver at his 12 o'clock position. Radar data indicated that both aircraft passed within less than 600 feet of lateral separation at an altitude of 2700 feet.
The investigation
The investigation examined the safety defenses present during the encounter, including airspace classification, visual scanning, and air traffic control services. It was noted that within the Class E transition airspace between Vancouver and Victoria, VFR aircraft may operate without transponders or communication with ATC. This creates a environment where high-speed IFR flights and unidentified VFR targets share the same airspace.
The investigation also looked into the effectiveness of visual detection aids. While both aircraft were equipped with transponders, neither was equipped with a Traffic Alert and Collision Avoidance System (TCAS). The investigation also reviewed the controller's workload and the limitations of radar scanning for unidentified VFR targets in Class E airspace, which often appear on radar without associated data tags.
Findings
- The Victoria terminal controller failed to detect the presence of the Otter, likely due to divided attention among multiple tasks, which degraded his radar-scanning effectiveness.
- Delayed traffic advisories impaired the ability of both flight crews to detect the opposing aircraft through visual scanning.
- The lack of TCAS equipment on either aircraft meant there was no automated system to alert the pilots to the impending conflict.
- The altitude deviation of the C-FRNO contributed to the risk, though it was not the primary cause.
- The current operational environment allows IFR flights to be cleared into Class E airspace shared with uncontrolled VFR traffic, creating a known risk of collision.