Britain's Rolls-Royce said on Monday a costly problem affecting the durability of a certain type of Trent 1000 engine had spread to another type and would require further inspections, affecting customer Boeing.
Rolls has been battling to fix a problem with the compressor in the Trent 1000 package C engines that power Boeing's 787 Dreamliner jet, forcing planes to be grounded while they are fixed.
Rolls said on Monday it had now found the same issue on a "small number of high life Package B engines" and it had agreed with Boeing to carry out a one-off inspection of the B fleet, to further understand the scale of the problem.
The Package B engine has been in service since 2012 and consists of 166 engines.
Rolls, which is trying to fix the engine problem at a time of huge restructuring and job cuts, said that while this new problem would incur some additional cost, it did not expect it to affect its free cash flow guidance for 2018.