Thai Airways is grounding some of its Boeing 787-8s due to delays in repairing engine problems that have been affecting other operators of Rolls-Royce Trent 1000 engines.

The carrier has not specified how long the aircraft will be parked, but stated the engine spare parts issues will be “alleviated” in August, with a “return to normal” in September. Local media has reported that four of the airline’s six 787s have been grounded.

Other operators of 787s with the Trent 1000 engines are also having to replace engines or engine parts due to concerns about turbine blades. The problem first arose with All Nippon Airways last year.

Thai Airways noted the problem “may affect flight safety,” so it removed engines from its 787s and sent them for repair at the Rolls-Royce technical maintenance center in Singapore. “Due to the large and increasing amount of engines that experienced problems worldwide, Rolls-Royce is unable to complete repair work in the established time frame,” said Thai.

The carrier said it has arranged for other aircraft to fly the routes usually operated by the 787s, so there should be “no impact on passenger service.” Thai said it “has also negotiated with Rolls-Royce to provide compensation for expenses incurred as a result of this situation,” although it has not specified an amount.

While the carrier has no more 787-8s on order, it is due to receive two of the -9 variant later this year. Thai also operates Airbus A350s. An airline executive recently told Aviation Daily that 787-9s and A350s are contenders for another order for 17 widebody aircraft the carrier is considering.