A helicopter pilot involved in a fatal collision would have had only 15 seconds to identify the presence of another aircraft before the crash, a former Civil Aviation Authority safety investigator says.
Peter Kirker was giving evidence at an inquest into the deaths of two trainee pilots and an instructor who died in the crash over Paraparaumu in 2008.
Trainee helicopter pilot James Taylor and his examiner David Fielding died when their helicopter collided with a Cessna being flown solo by Bevan Hookway.
The inquest earlier was told that Mr Hookway was doing an overhead rejoining manoeuvre shortly before.
Mr Kirker told the inquest on Tuesday that crash investigators had not considered the amount of supervision given to Mr Hookway or what instructions he had been given about the manoeuvre.
He said there was a lot going on for the young pilot and it was possible that he had trouble interpreting what the helicopter pilot was referring to in radio calls shortly before the crash.