"...the mail runs had been running for about fifteen years,..."
The rural mail services have their origins in the RASS (Rural Air Services Scheme) services, negotiated between Sir Bob Norman (of Bush Pilots Airways) and Athol Townley, then Minister for Civil Aviation, in 1954. The RASS services carried mail and rural residents and were
always air charter operations until deemed otherwise in 1999 under Mick Toller.
CAR 206 has it's origins in ANR 197 to ANR 203, which related to exemptions to conduct scheduled services over protected airline routes.