A fatal helicopter crash in Bluff Harbour was probably caused by student pilot error, an investigation has found.
Sixty-seven-year-old student pilot Allan Munro and his 29-year-old instructor Jason Wright, 29, were killed in the 14 October 2010 accident, when the Robinson 22 helicopter they were in crashed into the harbour.
Mr Munro is believed to have been practising a simulated engine problem exercise called an 'autorotation' before the crash, said a Civil Aviation Authority (CAA) report released today.
The aircraft was seen "repeatedly descending to low level over the coast of Bluff Harbour and then climbing away again", but there were no witnesses to the accident.
If mishandled, an autorotation could result in the helicopter blades stalling, said the report.