Fact 1. Army pilots did fly the aircraft as PIC without Unionair pilots
I cannot recall any Army pilots flying either RUU or FWG without UnionAir pilots as PIC between 1970 and 1980. If they did it would have been after 1980.
Fact 2, These two aircraft in PNG operations struggled to get above about 18000 at the weights they were operated at.
We really only had one weight and that was MTOW. With the APR in RUU, there was no requirement to climb above 7000 feet above the terrain as this was timing limitation of the APR. But when required for photography, 25000 was a long climb but doable.
Fact 3. Helmets were not worn by Army pilots whilst flying these aircraft and the oxy system was a constant flow system fitted by Unionair
RUU had the same system as fitted to the Porter and that included the masks and helmets.
RUU at Rendani
