A former Civil Aviation Authority safety investigation manager has outlined other near misses between planes and helicopters performing the same overhead manoeuvre done by a teenage pilot moments before a fatal collision.
An inquest has resumed in Wellington into the crash which killed teenage Cessna pilot Bevan Hookway, 17, flight examiner David Fielding, 30, and helicopter pilot James Taylor, 19.
Taylor was doing a final test flight with Fielding when their aircraft collided on February 17, 2008. Mr Hookway was performing what is called a joining procedure.
The men were killed when the helicopter fell into the Paraparaumu Placemakers store and the plane crashed into a residential street. The inquest has resumed after more than a year's break before Wellington coroner Ian Smith.
The hearing is expected to hear from five witnesses.
Peter Kirker, who left CAA in 2011, told Mr Smith that there had been a near miss at the Paraparaumu airport in 2007 between a plane and helicopter during the same manoeuvre but CAA was not notified until after the fatal crash.
More than a year later a similar near miss happened in New Plymouth. Mr Kirker said he had been called the day of the accident and as required informed the Transport Accident Investigation commission but they did not come out and did not take over the investigation until late the next day.
He said he then created a flight simulation programme to show what both pilots would have seen and found there were difficulties in what they would have been able to see.
He said CAA had known about the risk with the overhead join manoeuvre since 1996 and the collision could have been prevented if CAA had acted on its own safety recommendations.
Mr Kirker said it was difficult to understand why nothing had been done about the manoeuvre, like different altitudes for each type of aircraft to put distance between them.
They could have given a safety warning that there was a collision risk, he said.
"There was limited oversight at the Paraparaumu aerodrome at the time of the accident,'' he said.
At the time Paraparaumu was uncertificated. Only when the aerodrome has the CAA certificate does CAA have any power to enforce recommendations
- The Dominion Post
Is it worth it to fund a war museum in the capital for $18m?