Incident
at 8NM MONTRÉAL / PIERRE ELLIOTT TRUDEAU INTL QC (CYUL)
A WestJet Encore Ltd. de Havilland DHC-8-402 (C-FWEZ/WEN3543) from Montreal/Pierre Elliott Trudeau, ON (CYUL) to Toronto/Lester B. Pearson, ON (CYYZ) was cleared to 5,000 feet. After briefly levelling off, the aircraft was observed at 5500 feet, 2.5NM behind a Jazz Bombardier CL-600-2D24 (C-GOJZ/JZA8970) from Ottawa/Macdonald-Cartier, ON (CYOW) to Montreal/Pierre Elliott Trudeau, QC (CYUL).
UPDATE from Flight Operations: A Civil Aviation Safety Inspector (CASI) looked into this occurrence. Shortly after departure, the crew was made aware of potential conflicting traffic 1000ft above their assigned altitude. Visual confirmation of the traffic was made by the crew. At the time of acknowledging and passing the conflicting traffic, the crew was assigned a heading by air traffic control (ATC). The pilot that was flying, upon hearing the instruction given by ATC, began to both initiate the turn (as directed), but also self-initiated a climb. The climb was initiated in error due to the flying pilot anticipating a higher altitude because the potential traffic no longer posed a threat. The flying pilot quickly realized their error, and elected to gradually level off for guest comfort. The 400ft deviation in altitude can be attributed to the gradual altitude capture rather than an abrupt one (again, because the conflicting traffic posed no threat). The Flight Safety Standards pilot debriefed with the flight crew following the event, and reviewed the following contributing factors leading to the altitude deviation, which included: expectation of being assigned a clearance (i.e. confirmation bias); role transfer and the subtle disorientation operating from a seat not commonly occupied by the Pilot Flying (PF); and a lightly loaded aircraft, namely in increased climb performance.
