A tragic helicopter crash over Lake Wanaka that killed pilot Matt Wallis - three months before his brother Nick Wallis also died in a chopper crash - was caused by mast bumping. Mast bumping is contact between an inner part of a main rotor mechanism and the main rotor drive shaft. Photo / SuppliedIt was likely strong unexpected turbulence caused the main rotor disk to teeter excessively and the mast to bump, she said. Wallis' brother and two other people were killed in another helicopter crash near Wanaka Airport in October 2018 - also believed to have been caused by mast bumping. Photo / David Paull / NZ Civil AircraftTAIC has previously raised concerns about the number of accidents in New Zealand in which Robinson helicopters have experienced mast bumping.

Source: New Zealand Herald November 26, 2020 00:08 UTC