Engine maker Rolls-Royce has warned over customer disruption and higher costs as it carries out additional inspections on some Trent 1000 engines.
In March the engineering firm revealed a charge of around £340 million for repairs on existing engines, but on Friday it said the requirement for more regular inspections will lead to “higher than previously guided cash costs”.
Last month it said up to 500 Trent 1000 engines – used on Boeing 787 planes – were affected by the issues, which see components wear out earlier than expected.
Rolls said that 380 Package C engines, which are under review, are currently in service with airlines, but added that the Trent 1000 Package B and Trent 1000 TEN are not impacted.
Rolls said on Friday: “As part of our ongoing inspection and testing of those engines we have decided to carry out additional engine inspections to those previously planned.
“These inspections will be supported by service management and flight operations guidance to airlines to be issued by the airworthiness authorities.
“This will unfortunately lead to additional disruption for our customers.”
The group said that the move is driven by its further understanding of the durability of the Trent 1000 Package C compressor.
Nevertheless, Rolls confirmed its free-cash-flow guidance for the year at around £450 million.
Boss Warren East said: “Our focus is on supporting our customers and doing all we can to minimise any impact on their operations.
“We sincerely regret the disruption this will cause to our customers and our team of technical experts and service engineers is working around the clock to ensure we return them to full service as soon as possible.
“We will be working closely with Boeing and affected airlines to minimise disruption wherever possible.”