Rolls-Royce has acknowledged that it expects to deliver fewer Trent 7000 engines in the fourth quarter than originally planned.
This reflects "early-stage production ramp-up challenges", says the UK engine maker, which now foresees that full-year large-engine deliveries will come it at around 500, rather than 550 as previously targeted.
"We regret the impact this will have on our customers," says Rolls-Royce.
The manufacturer has left unchanged the 2018 profit and cash-flow financial guidance it issued in August.
Rolls-Royce stresses that it has seen "very good performance attributes during a rigorous testing phase" for the Trent 7000, which powers the Airbus A330neo – the first of which is poised for delivery to launch customer TAP Air Portugal, after the type last month secured European Aviation Safety Agency certification.
"We continue to work very closely with Airbus and our customers on the details of the delivery schedule," says Rolls-Royce.
It observes that production ramp-up issues at early stages of a new engine programme "are not uncommon in our industry", and adds: "As we move into 2019, we are confident that Trent 7000 production and delivery volumes will increase significantly to meet our customer commitments."