US helicopter operator Era Group has cautioned that it sees no rapid return to service for its fleet of nine Airbus Helicopters H225s, despite the type having been cleared for operations by regulators.

In its financial filing for the quarter ended 30 June, Era says the type is flying again on oil and gas missions in only "a handful of countries in Asia".

Any "broad-based" restart of operations will depend on customers and passengers having confidence in the safety measures mandated by regulators, it says.

"We will not operate the H225 helicopters in our fleet unless and until we can develop a detailed safety case that demonstrates the H225 model helicopter can be operated safely."

Bristow Group has also recently sounded a similar note of caution. Operations with its 27 H225s "remain suspended globally", chief executive Jonathan Baliff told a first quarter earnings call on 4 August.

He says the company will be "very cautious, very deliberate and very methodical as we develop and implement a return to service… for the H225". That plan will include collaboration with HeliOffshore, customers, passengers and unions, he says.

However, Baliff cautions that there is presently "not a lot of demand" for the H225 – for both operational and image reasons – but Bristow will shortly begin flight tests of four aircraft it intends to return to lessors this year.

The H225 was grounded in the wake of a fatal crash off Norway's west coast on 29 April 2016 in which 13 people were killed.

Norwegian investigators have determined that a fault with the second-stage planet gear was to blame for the failure of the main gearbox, but have yet to identify a root cause for the accident.

Although European regulators cleared the type to resume passenger flights in October 2016, the civil aviation authorities in Norway and the UK maintained their grounding orders until 7 July this year.

In the meantime, Era is continuing to pursue Airbus Helicopters through the US courts, alleging that it sold H225s with the full knowledge of a safety issue with the main gearbox.

Court filings show that Era is seeking substantial compensation from the manufacturer. It argues that its H225 fleet has lost "substantial value" since the Norway crash, on top of costs incurred from the flight ban.

It argues that Airbus Helicopters "fraudulently" presented the H225 as one of the safest rotorcraft in its class and "concealed any and all internal doubts and conclusions over the design of the H225’s main gearbox when it was certified".

Airbus Helicopters had previously denied the allegations but now declines to comment further because of the ongoing legal action.

Recent filings, dated 2 August, indicate that Era has applied to the UK courts seeking the disclosure of considerable documentation from London-headquartered Babcock International related to the fatal crash of an AS332 L2 in 2009 near Peterhead. That aircraft (G-REDL) was operated by Bond Offshore Helicopters, which was subsequently acquired by Babcock.

Norwegian investigators have linked the two accidents, blaming spalling – or degradation of a bearing race – for initiating the fracture that caused the second-stage planet gear to fail.

In addition, Era has made a similar application to the French judicial authorities seeking evidence from bearing manufacturer NTN-SNR Roulements (SNR).

That company makes one of the two types of second-stage planet gears used in the H225. However, its products have not been implicated in either accident, with the gears manufactured by rival FAG instead withdrawn from service.

"SNR – as one of the two companies responsible for manufacturing planetary gears for the [H]225 and [AS]332 L2 – has access to communications, documents and other information regarding Airbus Helicopters’ knowledge of the [H]225’s defects," the court application says.

"Understanding the communications between Airbus Helicopters and SNR and others regarding the SNR and FAG gears following the 2009 Peterhead crash is critical to Era’s claim," it says.

Airbus Helicopters faces separate claims over the H225 crash and subsequent grounding from finance firms ECN Capital (Aviation) and Wells Fargo Bank.