An Airlines PNG plane is reported missing having failed to reach its destination near Papua New Guinea's Kokoda Track.
The Twin Otter, twin engine, plane left the capital Port Moresby on Tuesday morning but had failed to return by Tuesday afternoon.
Authorities say there are 15 people on board, including eight Australians heading to the Kokoda Track, five local porters and two crew.
The plane had been flying through the Owen Stanley ranges that are famous for its mountainous and rugged terrain.
The weather in the area is very bad and completely overcast.
An Airlines PNG plane has begun a search and rescue mission.