July 19, 1996
Incident at 50 NW Regina, Saskatchewan
An operating irregularity occurred between NW1845, a DC9 which was enroute Saskatoon from Minneapolis at FL330 and Canadian 900, a Boeing 737, enroute Montreal from Calgary also at FL330. NWA1845 were assigned a heading to cross behind CDN900. CDN900 received a TCAS alert and started to climb from FL330. The aircraft passed with 500 feet vertical separation and 4.25 miles lateral separation.