What happened
On a day with clear visual meteorological conditions, two Piper PA-44-180 Seminole aircraft experienced a near mid-air collision in the Abbotsford control zone. The first aircraft, C-FHDP, was conducting a training flight under instrument flight rules (IFR) and was executing a missed approach procedure at Abbotsford International Airport. Simultaneously, a second Piper PA-44-18 and Seminole, registration C-FCFZ, was transiting the area under visual flight rules (VFR) at 2500 feet above sea level.
As C-FHDP climbed through 2100 feet as part of its missed approach, it approached the altitude and path of C-FCFZ. The Victoria terminal controller identified the impending conflict on radar and instructed the pilot of C-FHDP to halt their climb at 2000 feet. This maneuver allowed the two aircraft to pass with approximately 0.75 nautical miles of lateral separation and 500 feet of vertical separation, narrowly avoiding a collision.
The investigation
The investigation examined the coordination between Abbotsford tower and Victoria terminal. It was established that the Abbotsford tower controller had transferred both aircraft to the Victoria terminal frequency without providing traffic information or ensuring a safe flight path. The investigation found that the tower controller released C-FCFZ from his frequency without a plan to prevent conflict with the IFR missed approach being performed by C-FHDP.
Furthermore, the investigation looked into the radar display capabilities. The radar return for C-FCFZ appeared as a digital target showing only altitude, lacking registration and speed data. This made the target less conspicuous to the Victoria terminal controller, who primarily monitors targets with full jurisdictional data tags.
Findings
- The Abbotsford tower controller released the VFR aircraft, C-FCFZ, and the IFR aircraft, C-FHDP, from his frequency without a plan to ensure their paths would not intersect.
- No traffic information was provided to either aircraft, which increased the risk of a collision.
- A local practice of avoiding prior coordination between Abbotsford tower and Victoria terminal for VFR traffic was in place to reduce workload, but this practice increased the risk of a lack of coordination between units.
- The tower controller failed to take aggressive action to alert the terminal controller once the conflict became apparent.
- The radar target for C-FCFZ was difficult to detect because it lacked registration and speed data on the controller's display.