The photo below is of two Hazair PL-12 Airtruks, taken at Albury, NSW c.1981. Hazair have been operating Airtruks in one form or another for about four and a half decades. These two were late versions of the Continental IO-520 aircraft; although it is a bit hard to tell, since most operational Airtruks were extensively updated over the years.
Below :- a different kind of Airtruk – the 400hp, Lycoming O-720 powered T-400 Skyfarmer with the 300hp, Lycoming O-540 powered M-300 multi-role military Airtruk in the background. This was at Bankstown Airport c.1988 – notice that by this time the control cable fairings on top of the tailbooms had been extended upward into dorsal fins. This would give better directional stability without the hassle of completely redesigning the vertical tails.
Below:- The mortal remains of VH-HSB at HARS Albion Park, December 2011. The aircraft was built in 1968, went to New Zealand, came back to Australia 20 years later, and finally wound up derelict at Bathurst, NSW by 2008. It’s now being restored by the Queensland Air Museum at Caloundra, with tailbooms coming from another wreck, VH-TTV – an Australian operated Airtruk that had spent its early life in South Africa. There weren’t all that many Airtruks built, but they certainly got around!