Wild weather has damaged an Auckland Westpac rescue helicopter, with a strong, unexpected wind gust knocking its rotors into the tail while four crew were onboard.

The chopper, BK-117, had just landed after completing a mission and was powering down about 2pm last Friday when the incident occurred.

The BK-117 chopper had just landed after completing a mission and was powering down about 2pm last Friday when the incident occurred. Photo / Supplied Auckland Rescue Helicopter Trust

The pilot, a co-pilot, a critical care paramedic and a pre-hospital and retrieval medicine doctor were on board.

“Thankfully, there were no injuries to any crew or staff on the ground,” a spokesman for Auckland Rescue Helicopter Trust said.

The extent and significance of the damage to BK-117 is being assessed. Photo / Auckland Rescue Helicopter Trust

The Civil Aviation Authority was notified of the incident, he said.

The extent and significance of the damage was being assessed.

The Herald has approached the Auckland Rescue Helicopter Trust for further comment on any potential impacts to its operations.