Near-collision between two aircraft near Québec Airport due to equipment error and controller distraction

Casualties unknown • 12 nm SW of Québec/Jean Lesage, CA

A student pilot's failure to set a transponder altitude mode and a controller's loss of situational awareness nearly led to a mid-air collision near Québec/Jean Lesage International Airport.

What happened

On a VFR cross-country flight returning to Québec, a Cessna 172, registration C-GYQB, came within 200 feet vertically and 500 feet laterally of a Cessna 208 Caravan operated by Morningstar Air Express. The Cessna 208 Caravan, flight MAL7069, was performing an IFR departure from Québec Airport and climbing through 3000 feet when the near-collision occurred.

Prior to departure from Trois-Rivières, the student pilot operating C-GYQB failed to complete a checklist item, leaving the transponder in standby rather than the altitude encoding "ALT" position. While the pilot entered the assigned squawk code, the lack of altitude encoding meant the aircraft appeared only as a primary radar symbol without a data tag on the controller's screen.

During the flight, the Québec terminal controller provided a transponder code to the student pilot but did not follow up to confirm the aircraft's position or altitude. As the controller focused on managing inbound IFR traffic and coordinating with the tower, the primary radar symbol for C-GYQB went unnoticed. Although the controller eventually issued traffic information to the Cessna 208 Caravan, the proximity of the two aircraft left the crew with insufficient time to perform evasive maneuvers.

The investigation

The investigation examined the cockpit procedures of the student pilot, the operational workload of the Québec terminal controller, and the technical functionality of the radar situation display (RSiT). Investigators looked into the impact of the recent merger of the Ottawa and Québec terminal control units and the specific software behavior of the RSiT system, which caused flight plan entry windows to disappear automatically after 30 seconds.

Findings

  • The student pilot's failure to set the transponder to the altitude encoding position prevented the transmission of altitude and identity data to air traffic services.
  • The Québec terminal controller did not perform a radar identification of C-GYQB or request essential flight data, allowing the aircraft to enter Class D airspace without adequate radar service.
  • The controller's attention was diverted by high workloads, including managing multiple IFR arrivals and intensive coordination with the Québec tower.
  • The RSiT software's automatic closure of the flight plan window removed a potential visual reminder of the pending task.
  • The student pilot's lack of experience contributed to the checklist omission and the failure to query the controller regarding radar identification.

Probable cause

The near-collision was caused by a combination of the student pilot's failure to activate altitude encoding on the transponder and the air traffic controller's loss of situational awareness due to high workload and technical system timeouts.

Frequently asked questions

What happened in the 2004-08-05 Montréal Area Control Centre accident near 12 nm SW of Québec/Jean Lesage, CA?

A student pilot's failure to set a transponder altitude mode and a controller's loss of situational awareness nearly led to a mid-air collision near Québec/Jean Lesage International Airport.

What aircraft was involved and where did it happen?

The accident on 2004-08-05 involved a Montréal Area Control Centre, operated by NAV CANADA, at 12 nm SW of Québec/Jean Lesage, CA.

What was the probable cause of the accident?

The near-collision was caused by a combination of the student pilot's failure to activate altitude encoding on the transponder and the air traffic controller's loss of situational awareness due to high workload and technical system timeouts.

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