The Transport Accident Investigation Commission (Taic) said today it reopened its inquiry into the crash of the Robinson R44 in the Lochy River valley after receiving new evidence about the mental health of Stephen Anthony Nicholson Combe.
Mr Combe (42) and James Louis Patterson Gardner (18) died on February 19, 2015, when the helicopter crashed during a training flight in the Eyre Mountains, southwest of Queenstown.
In its original report on the crash, released in August last year, Taic identified "mast bumping'', which caused the rotor blade to hit the cabin, as the cause.
Taic said today it resumed the investigation a month later, after receiving new evidence about Mr Combe's mental health.
However, it had concluded it was "very unlikely'' any medical factor contributed to the accident, and its original findings into the accident remained unchanged.
". . . it is very likely the instructor was medically fit to fly when his most recent medical certificate was issued.''
However, Taic found there were "too many ways for a holder of an aviation document to circumvent the civil aviation process designed to prevent pilots flying if they are not medically fit to do so''.
As a result, it had made several recommendation to the Civil Aviation Authority and the Ministry of Health to address those issues.
In its original report on the crash last year, Taic found the cause of the mast bump and resulting in-flight break-up could not be conclusively determined.
The helicopter was operated by Queenstown company Over the Top.
