Flight PX73 was making a scheduled stop at Chuuk International Airport on the way from Pohnpei to Port Moresby on Friday, September 28.
The Boeing 737-800 was on final approach in very poor weather according to the airline.
At 10:10am local time the plane crashed short of the runway into the lagoon in heavy rain and reduced visability the airline said in a statement.
The plane later sank in the lagoon after passengers and crew were evacuated to Chuuk's main island of Weno.
