Investigators believe the sole fatality in the Air Niugini undershoot accident at Chuuk was a passenger who was not wearing a seat-belt at the point when the Boeing 737-800 struck the surface of the sea.
Air Niugini had originally claimed that all 35 passengers and 12 crew members had evacuated the aircraft after the jet came down 1,500ft short of Chuuk's runway 04 on 28 September last year. But subsequent information indicated that one passenger was missing.
On the day of the accident US Navy divers informed a rescue co-ordination meeting that they had searched the aircraft "from front to back, and back to front, and that the cabin was clear", says the Papua New Guinea Accident Investigation Commission.
"The search parties, therefore, concentrated their search away from the aircraft," it adds.
Three days of searching failed to locate the missing passenger – who had been in window seat 23A, five rows from the rear of the jet – and the investigating commission requested a verification search of the 737.
Experienced Japanese divers, seconded by the government, were taken to the site and, after a search co-ordinated by the commission, the missing passenger was located between seat rows 22 and 23, in the vicinity of a fuselage fracture.
Pathological analysis found that the passenger had succumbed to injuries within 3min of the impact, and that there was no evidence that he had drowned during the evacuation, even though water had rapidly entered the jet as a result of the aft fuselage damage.
An autopsy determined that there was a lack of trauma around the waist and hips, indicating that the passenger "was not wearing a seat-belt" at the time of the crash.
"[This] allowed his body to become a projectile resulting massive head trauma injuries," says the inquiry.
During the descent the captain had told cabin crew to prepare the cabin for arrival. The cabin crew then made a public announcement stating that the seat-belt sign would "shortly be illuminated" and that, once switched on, movement in the cabin would be restricted.
"There was no recorded information to confirm that cabin crew informed passengers to fasten their seat-belts," the inquiry says.
"However, in written answers to the investigation’s passenger questionnaire, passengers stated that the seat-belt signs were switched on and the 'fasten seat-belt' announcement was made for landing."
Cabin crew and passengers on the aircraft are credited with assisting several seriously-injured occupants from the jet, including the passenger seated in 22A, immediately ahead of the fatality.
This passenger had been found underwater in the aisle and a cabin crew member lifted him above water level and, with the help of another flight attendant, pulled him to an overwing exit and helped him into a rescue boat.
Another passenger was found still strapped into seat 17F, and a flight attendant unfastened his seat-belt before dragging him to the same exit.
Thirty of the 46 surviving occupants were evacuated through the left overwing exits. Eleven more escaped from the right aft overwing exit, and the other five – including the two pilots – emerged from the forward left-hand door.
Investigators noted that the passenger safety card for the aircraft (P2-PXE) incorrectly indicated that there was an evacuation path to both forward exits, with a life-raft deployed from each, whereas the emergency procedure after ditching involves opening only the left-hand forward exit.