EASA has lifted the temporary flight suspension of the Airbus Helicopters Super Puma EC225 LP and AS332 L2.
The Civil Aviation Authority said its restrictions on the aircraft will remain pending investigations into the accident.
This suspension was put in place on June 2 following the crash of CHC Helikopter-operated EC225 that killed 11 passengers and both pilots in April.
An investigation, led by the Accident Investigation Bureau of Norway, found the cause of the accident to be the main gearbox. More than 27,000 people signed a petition following the accident to revoke the airworthiness certificates for the Super Puma and to remove it from service. However, Airbus stood by its aircraft, believing in its future operation.
Several measures concerning the gearbox were, and shall be, taken to enable the end to the suspension. These include replacing the type of stage main gearbox planet gear, which was involved in the accident, with another type that has demonstrated reliability. It also calls for decreasing the time before replacement of this other gear type by more than 50%, requiring daily inspection or after 10 flight hours (whichever comes first) of the chip detectors and requiring inspection of the oil filters against stringent criteria (every 10 flight hours).
All main gearboxes that have experienced external events that could have lead to stress, visible or not, will be taken out of service.
The Swiss Air Force had already resumed its flights prior to EASA’s announcement.