Lethbridge Airport had become more regional in nature. According to Trans-Canada's system timetable dated April 29, 1962, the airline was operating Vickers Viscount turboprop service on a routing of Lethbridge-Calgary-Edmonton and was also flying Douglas DC-3 service with a routing of Lethbridge-Medicine Hat-Swift Current-Regina-Yorkton-Brandon-Winnipeg. Trans Canada would become Air Canada which in turn continued to operate Vickers Viscount turboprop service on the Lethbridge-Calgary-Edmonton route before ceasing all scheduled passenger service to Lethbridge during the early 1970s. Time Air was a regional airline that initiated operations in Lethbridge. Founded in 1966 as Lethbridge Air Service, Time Air flew a variety of turboprop aircraft
Vickers hardness test the material. The fin attachment pins and sleeves in the Convair 580 airliner were specified by the aircraft manufacturer to be hardened to a Vickers Hardness specification of 390HV5, the '5' meaning five kiloponds. However, on the aircraft flying Partnair Flight 394 the pins were later found to have been replaced with sub-standard parts, leading to rapid wear and finally loss of the aircraft. On examination, accident investigators found that the sub-standard pins had a hardness value of only some 200-230HV5. Vickers hardness test The Vickers hardness test was developed in 1921 by Robert L. Smith and George E. Sandland