A Special Bulletin released by the UK Air Accident Investigation Branch confirms that the 1 April crash of a Bond Helicopters Eurocopter AS332L2 Super Puma G-REDL was caused by the "break-up of the epicyclic [reduction] gear stages" of the main gearbox, which caused the main rotor to separate. The crew had no useful warning of the impending failure, says the agency, and the aircraft fell into the North Sea 15km (9.3 miles) off Peterhead, Scotland, killing all on board.

The AAIB has issued two recommendations in addition to those published on 17 April, requiring the European Aviation Safety Agency to strengthen maintenance procedures "to ensure that correct identification of the type of magnetic particle is maximised", and to review the design, operational life and inspection processes for planet gears in AS332L2 and EC225LP helicopters.

Source: Flight International