CHC Helicopter has begun flight tests of a Eurocopter EC225 fitted with the full range of EASA-mandated safety modifications from its base in Aberdeen, Scotland, as it attempts to return its global fleet of 32 of the type to operation.
It was the October ditching off Shetland of a CHC Scotia aircraft (G-CHCN) that prompted regulators in the UK, Norway and Denmark to ban overwater flights with the type, effectively grounding the Super Puma in the North Sea region.
Now CHC is on track to be the first operator to get its EC225s back in the air, with the initial unidentified aircraft having received Eurocopter's safety fixes, following their approval by EASA on 9 July, and commenced flight trials on 18 July.
CHC says its engineering teams are taking four to five days to complete the modifications, with the bulk of the work accounted for by the addition of an in-cockpit system to alert the pilots to the propagation of cracks in the main gearbox bevel gear vertical shaft.
A circumferential crack in the bevel gear shaft was later pinpointed as the cause of the CHC ditching and that of a previous incident involving a Bond Offshore EC225 (G-REDW) in May 2012.
"Our pilots completed the first test flight of a modified EC225 [on 18 July] in Aberdeen. A ground run and flight test saw the aircraft operate normally, as anticipated. The flight test lasted under one hour," says CHC.
"We are continuing to modify and test other EC225s around the world, following the regulator-approved process to prepare for an imminent return to service." This will come "within weeks", it says.
Two further aircraft will be ready for flight tests early next week, with additional rotorcraft undergoing modification in Malaysia, Australia, Norway and Brazil, it says.
"At the same time, in partnership with industry safety groups and unions, we are providing information to customers, including offshore workers, so that they understand and can be confident in the return to service process," it adds.
Pan-industry organisation the Helicopter Safety Steering Group met on 17 July to discuss its position in relation to the EC225 and says it "fully supports" the plan to allow the helicopter to resume flights.
It says it will engage with the offshore workforce in order to reassure them of the robustness of the solution.