On Friday, UK and Norwegian authorities announced their intention to clear Airbus H225LP and AS332L2 helicopters to resume flight, provided operators adhere to new modifications and maintenance guidelines. The helicopters had been grounded in both countries shortly after the fatal crash of an H225LP (EC225LP) near Turoy, Norway, in April 2016. EASA had approved the model for return to service in October 2016.
The conditions for return to flight imposed by the UK Civil Aviation Authority and the Civil Aviation Authority of Norway focus around a second-stage planet gear in the epicyclic module of the main rotor gearbox—the component faulted as a main contributor to the Turoy accident by the Accident Investigation Board of Norway (AIBN) in a preliminary report issued on April 28. Requirements for return to flight include a change in the design by removing the components that were susceptible to premature deterioration; earlier replacement of components; a design change to introduce an improved maintenance inspection method to detect any deterioration at an early stage; more frequent inspections; and a reduction in the thresholds for rejecting components based upon early signs of any deterioration.
A plan of checks, modifications and inspections needs to be undertaken before any flights take place, including all required procedures, processes, tooling and training.