Police say it could be days before they know the cause of a gyrocopter crash in South Taranaki that left two men dead.
The light aircraft crashed into a paddock in Normanby, about 500m from State Highway 3 on Ohangai Road, about 1.30pm on Thursday.
Police say emergency services arrived quickly, but were unable to do anything to save instructor Stephen Chubb, 51, of Okaiawa, and Neville Adlam, 70, of New Plymouth.
Police say Mr Chubb was giving tuition to Mr Adlam when the crash happened.
The men's bodies were removed from the wreckage on Thursday night.
The Civil Aviation Authority is examining the scene.