The shattered remains of the Convair 580 after it was recovered from the sea off the Kapiti coast in October 2003. Picture/ Mark Mitchell
The pilots of a mail plane which crashed off the Kapiti Coast in October 2003 died from multiple injuries after the aircraft spun out of control because of heavy icing in freak weather, an inquest has found.
Wellington coroner Garry Evans endorsed the earlier findings of the Transport Accident Investigation
Commission (TAIC) which blamed a build-up of ice on the plane, causing it to stall and enter a spiral dive from which it could not recover.
Icing is hazardous to aircraft because it interrupts the smooth flow of air over the wings, creating drag and reducing control.
Mr Evans ruled that pilot Barry Cowley, 58, of Kaiapoi, Christchurch, and Paul Miller, 50, of Thames, both died of injuries sustained in the high speed crash.
The nature of the men's injuries indicated they were fighting for control of the plane when it hit the water.
The Convair 580, operated by Air Freight New Zealand, was on a scheduled freight flight from Christchurch to Palmerston North when it crashed about 9.30pm on October 3, 2003.
The weather was so bad that night that the main road between Kapiti and Wellington was blocked and a huge landslide engulfed houses at Paekakariki.
Mr Cowley's wife Jan wrote to Mr Evans last year saying she did not agree with TAIC's findings on the icing of the plane.
TAIC investigator-in-charge Ian McClelland said the aircraft had descended through an area of severe icing that was probably beyond the design and certified icing capabilities of the aircraft. Weather conditions had been "rare and extreme".
In her letter, Mrs Cowley said she believed that there were "likely to be a combination of problems" which caused the plane to crash, of which icing was just one.
Mrs Cowley said not all the wreckage was recovered from the sea, particularly major components such as the main cargo door, therefore it was impossible to determine if mechanical failure of these parts contributed to the crash.
The failure of the plane's cockpit voice recorder also meant valuable clues were lost.
She believed the best outcome would be to conclude the cause of the accident was unable to be determined.
- NZPA
