Robinson R-44 helicopters have been cleared to fly again in New Zealand after investigators there concluded that a rotor blade broke because of a crash and its failure didn’t cause the crash. Last Saturday, New Zealand grounded R-44s with Dash 7 rotor blades after preliminary inspection of the wreckage from a crash near Queenstown last Thursday revealed a blade broken at the same point as one that developed a fatigue crack in another aircraft a month earlier. Lab inspection of the blade in the second crash determined it likely sheared off when the aircraft hit the ground. Both occupants of the helicopter were killed. Director of Civil Aviation Graeme Harris lifted the flight ban Tuesday. Australia had also grounded the aircraft but there was no word late Tuesday if that had been cancelled, too. Meanwhile, there are still concerns about the first blade crack and the manufacturer has issued its own direction to operators.
On Monday Robinson Helicopters issued a safety alert mandating “careful visual inspection” during each pre-flight inspection of the rotor blade where it transitions from the hub to the extended chord. It’s in that location that a fatigue crack formed on a New Zealand R-44 in January. The pilot in that case noticed vibration and was able to land safely. The blade was shipped to Robinson and is being examined. New Zealand has left in place an AD requiring daily pre-flight inspections of the rotor blade until the cause of the crack can be determined.
