An ATSB accident investigation has failed to determine the cause of the fatal crash of a Cessna 182Q off Moreton Island in January 2020.
The final report, released today, focused on the potential for carburettor icing and the noted that the aircraft appeared to have been descended to an altitude over water that wouldn't have allowed a glide back to land.
VH-WNR was being flown on a private scenic flight from Caloundra Airport in QLD when it crashed into the sea near Flinders Reef only seconds after the pilot issued a brief Mayday call. The aircraft had been tracking north up the east coast of Moreton Island when the pilot began a descent towards the reef from 1200 feet. Inspection of the wreckage showed significant damage and neither the pilot nor the passenger have ever been found.
"ATSB examination of the underwater video identified that the aircraft was likely destroyed by collision with water at a moderately high speed," the report states. "Damage to the aircraft cabin from the collision with water indicated that it was unlikely to be survivable. There was no evidence of fire.
"All major aircraft components were accounted for, and there was no evidence of pre-impact defects or structural failure. As far as could be established, cockpit switch positions were configured as expected for normal flight."
The ATSB was unable to find any pre-existing defects with the engine or aircraft systems that could have caused the engine to fail and found evidence that the aircraft had 135 litres of fuel on board, which was sufficient.
However, the ATSB said the weather conditions at the time were conducive to carburettor icing, and although the carburettor heat control was found in the OFF position, investigators were unable to determine if the control had been applied prior to impact.
"ATSB analysis found that the engine’s power was reducing over the last part of the flight, over a period of about 100 seconds," the ATSB has said. "At the time of the accident, the weather conditions were conducive to carburettor icing. These conditions are common in the region.
"However, a conclusion regarding the possible influence of carburettor icing on the development of the accident could not be drawn with any certainty.
"The ATSB also found that the pilot had descended over water beyond the glide range of a suitable landing area twice on a previous flight, limiting the options for a forced landing in the event of an emergency.
"Although it could not be determined whether the aircraft’s descent out of glide range was intentional, pilots are reminded that the operation of single engine aircraft over water should at all times be conducted with consideration of the aircraft’s glide distance to a suitable landing area."
The full report is on the ATSB website.