Whats all this about the ATR not having an APU? The 72-500 that was in PNG had the right prop brake on and he engine was the APU. Flew very nicely but required a dispensation from the country of registration to allow it to land at Kunai due to the strip width. Other than that it fit the bill for the proposed job nicely. even had a 90min ETOPs approval.
I don't believe that APNG are actually looking at buying them though. The visiting one was here on proving flights for a particular contract and was proposed to be operated under the APNG AOC whilst its own FAOC application was being processed.
Quite possible I'm wrong though....... it happened once before.