The Civil Aviation Authority is grounding Robinson R44 helicopters fitted with a specific type of rotor blade until further notice as a safety precaution.
A Robinson R44 helicopter Photo: 123RF
The directive follows a helicopter crash at the Lochy River Basin on Thursday, which killed trainee pilot, James Patterson-Gardner, who was 18, and his 42-year-old instructor, Stephen Combe.
The wreckage has been removed from the crash site by transport investigators today.
Wreckage of the Robinson 44 helicopter that crashed on Thursday in a valley near Queenstown. Photo: NZ Police
The CAA said the grounding is effective immediately and will be in effect until further notice.
Civil Aviation director Graeme Harris said safety investigators have suggested a blade separation could have caused the crash.
He said there were similarities to a R44 incident in January, which also involved a Dash 7 Main Rotor Blade.
"In that incident, the pilot experienced severe vibration but was able to land the aircraft safely."
Mr Harris said the blade from the January incident was on its way to the manufacturer at the US Federal Aviation Administration for analysis.
He said grounding the helicopters did not pre-judge the outcome of the investigation into Thursday's accident.
"The initial advice from investigators on the scene is that this is a potential cause and given the previous failure we're already aware of we're really taking action in the public interest to ensure the safety of these aircraft."
Mr Harris said however it was possible investigators may learn the blade was not a problem.
The CAA believed the directive would affect about 80 aircraft.