Wellington coroner Ian Smith has expressed surprise that a young pilot was permitted to fly solo from a busy airport with just five hours' solo experience.
Trainee pilot James Taylor and his instructor David Fielding died instantly when their helicopter collided with a Cessna plane above Paraparaumu in February 2008.
The student pilot in the Cessna, 17-year-old Bevan Hookway, died later in hospital.
At an inquest on Tuesday, Mr Smith described Mr Hookway's flying out of Paraparaumu Airport with so little experience as a risky venture, given the fact it was a "massively busy" airport.
"The two don't match," he said.
Earlier, the inquest heard Detective Sergeant Ian Martin explain how Mr Taylor was conducting a move to simulate engine failure on approach to Kapiti Coast Airport.
Mr Hookway was conducting an overhead rejoin manoeuvre to circle the airport.
Police say no emergency calls went out from either plane, there were no distressed radio calls from the pilots and it appears the two aircraft collided while carrying out recognised moves in the correct manner.
Later reports by ESR also discounted alcohol and previously reported problems with flaps on the Cessna.
More than 20 family members are at the inquest which is hearing evidence from the Civil Aviation Authority, Kapiti Coast Airport and Kapiti Districts Aero Club.