The British engine manufacturer is investigating a problem with the compressor in its Trent 1000 engines, specifically its Package C batch.
However, the firm on Monday (June 11) confirmed a similar “durability issue” had been found on a “small number” of Package B variants.
Together with customer Boeing, the firm has pledged to carry out a one-off inspection of all 166 Trent 1000 Package B engines, which have been in service since 2012.
Rolls-Royce said details of the inspection would be published in the coming days, supported by an EASA airworthiness directive.
It said there would be a “limited impact” on customer operations. Rolls-Royce Trent 1000 customers include British Airways, Norwegian and Virgin Atlantic, the engine powering Boeing’s 787 Dreamliners among other aircraft.
Lars Sande, Norwegian’s senior vice-president of sales and distribution, last month told TTG the airline would not foot the bill for the impact of the engine inspection.
Chris Cholerton, Rolls-Royce president civil aerospace, said: “We are working closely with our customers to minimise any operational impact of these inspections and we deeply appreciate their continued co-operation. We remain absolutely committed to eliminating this issue from the Trent 1000 fleet.”
The cost of fixing the Package C engines was initially estimated to be around £370 million.
However, in April, Rolls-Royce said this figure would rise on account of the complexity of the operation and the compensation owed to customer airlines.
The full cost of the repair is expected to surpass £1 billion.
Meanwhile, Warren East, Rolls-Royce chief executive, is expected to announce changes to the business at an investor day in London on Friday (June 15).
These are understood to include around a 10% reduction of Rolls-Royce’s 50,000-strong workforce, with the majority of the cuts to hit middle-management roles, The Guardian reports.