The terrain around Kiunga is relatively flat and its not a particularly demanding strip, unlike Oksapmin and the "bips" in the highlands. The piston engine Islander is not great on one engine, particularly the 265hp version, can't comment on the turbine one.
Twelve on board is quite possible in PNG with babies and small children, there was a Twin Otter accident with around 28 onboard in the mid 1990s.
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