Defence Force Court of Inquiry has found an Air Force aerobatic pilot killed in a crash last year had a history of flying dangerously.
The investigation also found that he and other pilots had received no training in the manoeuvre he was practising at the time of the crash.
Squadron Leader Nick Cree, 32, a member of the Red Checkers display team, was practising a solo manoeuvre called the Fishtail Pass when he crashed near Bulls in Manawatu in January last year.
In a ruling issued on Tuesday, the Court of Inquiry found he had developed an unstable and dangerous technique to fly the manoeuvre which involves moving the nose of the plane to make the tail waggle like a fish.
Immediately before the crash, Squadron Leader Cree twice lost control of the plane, which the investigation found he did frequently without reporting the incidents.
It also found the pilot had never been trained in the manoeuvre and the supervision and monitoring was insufficient to correct the dangerous manner in which he was flying it.
Air Force 'let pilot down'
The Chief of the Air Force says the service let down the pilot "to a degree".
Air Vice-Marshall Peter Stockwell told Radio New Zealand's Checkpoint programme Squadron Leader Cree was an experienced pilot and the Air Force relies on them to make the correct judgements.
He says other Red Checkers pilots have flown that manoeuvre safely having been through the same system with the same orders, procedures, training and supervision.
"At the end of the day, Nick continued to fly it beyond the point that all other pilots had successfully flown it."
The Air Force says it has taken steps to improve the system.