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.
