Loss of Separation-Air Canada & Canadian Airlines-Langruth, Manitoba-18 January 1999

 Air Canada Boeing 767-233 C-GPWB and 
Canadian Airlines International Boeing 767-300 C-FCAG  Safety Action Taken
(as presented in the TSB Report)

The Canadian Air Traffic Control Association and NAV CANADA concluded a collective agreement which increased the minimum time between shifts from 8 hours to 10 hours and reduced the maximum consecutive hours of work from 12 hours to 11 hours.

NAV CANADA has initiated a process to reduce the number of extended shifts worked by controllers. As well, NAV CANADA has adopted a policy of staffing all air traffic services units to 105 per cent of NAV CANADA's defined staffing levels and has committed 50 million dollars annually to training in order to reach this goal.

Safety Action Required
(as presented in the TSB Report)

Risk-of-collision occurrences between large transport-category aeroplanes operating in a radar environment continue to occur in Canadian airspace. There are several ground and airborne layers of defence to prevent midair collisions caused by human errors. The last available ground-based defence that could have prevented this occurrence, human redundancy, was absent because the sector was operated by only one controller and the supervisor was actively controlling at another position. The TCAS provided an airborne defence that alleviated this dangerous situation. However, reliance on a TCAS as the sole automated defence against human error leading to midair collisions does not provide protection for all Canadian passenger-carrying aircraft. There are no Canadian regulatory requirements for TCAS installation on domestic, passenger-carrying aeroplanes, and there are no requirements for TCAS on any cargo aeroplanes.

The TSB has investigated other similar loss-of-separation occurrences (A98H0002, A97H0007, and A99W0064, under investigation) that contain many of the same elements addressed in this report. In the most recent occurrence (A00H0002, under investigation), two Airbus A340 aeroplanes were at the same altitude on undetected collision courses over the Gulf of St. Lawrence when the pilot of one aeroplane received a TCAS advisory and alerted the controller. These occurrences raise concerns about the lack of adequate, ground-based, conflict prediction and alerting systems in Canada.

The CASB identified the need to develop and install automated conflict prediction and alerting systems in the Canadian air traffic services system in its recommendation CASB 90-36. Although work has been ongoing over the years by Transport Canada, and most recently by NAV CANADA, there are no definitive commitments to set an implementation date.

There are serious consequences to midair collisions between large transport-category aeroplanes. Additionally, there is a lack of sufficient ground-based defences to contain normal levels of human error, which may lead to losses of separation. Therefore, the Board recommends, for the consideration of both NAV CANADA and the Minister of Transport, that:

NAV CANADA commit, with a set date, to the installation and operation of an automated conflict prediction and alerting system at the nation's air traffic control facilities to reduce the risk of a midair collision. (A00-15)

Transport Canada's Response:

NAV CANADA is in the process of developing an Air Traffic Control conflict alert system and will begin testing of the system in Toronto Area Control Centre by March 31, 2001. Transport Canada will monitor this testing and assess the necessity of a regulatory approach to address the Board’s recommendation.

Further, a Notice of Proposed Amendment (NPA) was presented at a June 2000 Canadian Aviation Regulations Advisory Council (CARAC) Technical Committee meeting. The NPA states "... by 1 January 2003 no person shall conduct a take-off in a turbine-powered aeroplane that has a maximum certificated take off weight of more than 15,000 kg or for which a type certificate has been issued authorising the transport of more than 30 passengers, unless the aeroplane is equipped with an Airborne Collision Avoidance System (ACAS) that conforms to the Aircraft Equipment and Maintenance Standards." The amendment to the Canadian Aviation Regulation (CAR) will exceed the International Civil Aviation Organization (ICAO) standard which will come in to effect in 2003.

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