In a weekend which saw a rare tornado in New Zealand rip a town apart, a massive directional change in strong winds caused nine tonnes of nacelle to come crashing down from atop the prototype Windflow Technology turbine operating just outside Christchurch, fortunately missing the two engineers working at the base of the tower. Windflow CEO Geoff Henderson says the wind swung through around 130 degrees, ripping through 50 degrees in just six seconds -- well outside the one-in-50-year tolerances -- and reaching prolonged gusts of 25 m/s. "There was a huge amount of horizontal wind shear," he says. The gearbox housing bolts pulled out, bringing it and the blades down. Henderson says work is already underway to retrofit the prototype with components already in development for a planned wind farm, Windflow is to supply in Palmerston North. International type certification of the Windflow, due to start the week after the accident, will be delayed, but as there are already challenges to the consent for the Palmerston North project, the overall development schedule may not be affected. Windflow shares heavily dropped on the news, but the bulk of small shareholders are strongly committed philosophically to supporting the project and retain confidence in the efforts of the New Zealand design and production.