FS2004 Safe Air Bristol B170 Freighter Mk31. Straits Air Freight Express of New Zealand commenced Bristol Freighter operations across Cook Strait in 1951. At its peak the operation had up to seventeen B170s and expanded into passenger transport to the Chatham Islands. The last four were retired 1987. Textures only; requires SB170.ZIP. Aircraft by Mike Stone. Textures by Paul Deans.