A helicopter flown by student James David Taylor, 19, with experienced rescue pilot David Fielding, 30, as his instructor, and a Cessna piloted by Bevan Andrew Hookway, 17, collided over Paraparaumu on February 17 last year, killing all three.
The helicopter fell through the roof of Paraparaumu's Placemakers store, just missing staff and customers, while the plane's fuselage landed about 250m away in Dennis Taylor Court, with its engine crashing through a house roof.
A report released today by the Transport Accident Investigation Commission (TAIC) said the airport's parallel runways made mid-air collisions a "well recognised" risk.
A 1996 safety review by the Civil Aviation Authority (CAA) identified "numerous safety issues" and made a list of recommendations including changes to the takeoff and landing procedure known as overhead joining.
The recommendation was not actioned.
"The reason for this could not be confirmed but was considered by the CAA to have been a decision by the then Director of Civil Aviation to allow the status quo to continue," the report said.
In a statement issued to media, the family of Mr Fielding, who worked as the base manager for the Palmerston North Square Trust rescue helicopter, said the CAA failed to do its job properly and ensure the safety of pilots flying in the Paraparaumu area.
The TAIC found the collision occurred when Mr Hookway performed a standard joining procedure that took him into the path of Mr Taylor's helicopter operating on a parallel grass runway.
"Had the conflict been recognised, the pilot of the aeroplane should have given way to the helicopter under general conflict-aviodance rules."
Neither of the pilots took evasive action in the moments leading up to the crash which suggested they were both "primarily focused on flying their aircraft".
"This may have been due to fixation on their respective tasks, task overload, or a combination of both."
Concerns about the pilots' age were unfounded but their inexperience may have been a contributing factor, the report said.
Both pilots had only recently taken up flying.
Mr Taylor had accumulated 76 hours of flying time, while Mr Hookway had flown for 25 hours.
"Both were considered competent and responsible students." investigator-in-charge Ian McClelland said. TAIC was not looking to place blame.
"We're not saying it's the fault of anyone. (Pilots) had grown used to the risk, it's not until this accident that people realised how bad that risk was."
The aircraft operators, aerodrome and CAA were all jointly responsible for ensuring the safety of pilots, he said.
"Preferred joining procedures" came into effect at the aerodrome in April this year.
Mr McClelland said the new procedure would ensure aircraft were kept separate but it was "unfortunate" it was not put in place sooner.
Had it been in place in February last year, the likelihood of the collision occurring would have been "significantly reduced", he said.
Following the crash an aerodrome user group meeting agreed to "discourage" standard overhead rejoins.
Kapiti Districts Aero Club also made several changes to safety procedures.
The TAIC report recommended the monitoring of aerodrome operations, the encouragement of good aviation practices and an operations review of aerodromes with opposing circuits.
CAA said it did not accept the recommended review as it was "constrained" by several issues.
"(The CAA) will undertake to make aerodrome operators aware of the risk associate with a `mix' of operational activities, and their need to develop appropriate local procedure to minimise the risk of mid-air collisions."
Mr McClelland said the victims' families had been in contact throughout the investigation and were "dismayed" that the situation continued for as long as it did.
In a statement issued to media, the family of Mr Fielding, who worked as the base manager for the Palmerston North Square Trust rescue helicopter, said the CAA failed to do its job properly.
"When anyone accepts a role that impacts on the safety of others they need to ensure that they carry it out with full knowledge of the consequences of their decisions."
The family also said it disagreed with the TAIC finding that the pilots failed to maintain an effective lookout.
"Unlike the rest of the report, this is speculation and not fact."
"As a direct result of the 1996 decision to make no formal changes to the overhead joining procedure...many in our community will live with the memory of seeing or dealing with a horrific accident."
"Three families and their extended friends and family will forever mourn the loss of those young men."
