Investigators trying to find out how two small planes collided mid-air near Feilding this week, have begun gathering information from witnesses.
Flying student Patricia Smallman, 64, and her instructor Jessica Neeson, 27, died when their Cessna crashed after the collision.
A student flying the other plane managed to land safely. He does not wish to be identified.
Lead investigator Ian McClelland says witnesses will include anyone who may have seen the crash, other people flying in the area at the time and emergency staff involved in the rescue.
He says the student pilot survivor has now been interviewed.