Air New Zealand (NZ, Auckland Int'l) has said it will ground two B787-9s for an extended period of time needed to conduct engine maintenance of two Rolls-Royce Trent 1000 units. For the duration of the repairs, the carrier will again wet-lease capacity from Portugal's Hi Fly (5K, Beja), the NZ Herald has reported.

The need for thorough maintenance surfaced after ANZ had conducted inspections of the Trent 1000 engines ordered by the European Aviation Safety Authority (EASA) in mid-April.

"As a result of the checks two Air New Zealand 787-9 Dreamliner aircraft will be temporarily removed from service while engines undergo maintenance work at a Rolls-Royce facility in Singapore Changi. Around 340 engines globally are subject to the checks and this is placing very high demand on Rolls-Royce’s maintenance facility, meaning it may take a number of months before Air New Zealand’s engine repair work can be completed," the New Zealandic flag carrier has said in a statement.

One of the affected grounded aircraft is most likely ZK-NZG (msn 37963) which has not flown since April 20, 2018.

According to the ch-aviation fleets module, ANZ currently operates eleven 787-9s. In addition to the recently grounded unit, ZK-NZE (msn 34334) has been grounded at Auckland Int'l since December 4, 2017, leaving the carrier with just nine active aircraft of the type.

The grounding of two B787-9s led to a number of cancellations, including services to Perth Int'l out of each of Auckland Int'l and Christchurch. Over the coming days, the carrier will reduce frequencies on some of its routes.

It is unclear what aircraft Air New Zealand will wet-lease from Hi Fly to cover for the grounded B787-9s. In December, when two Boeing widebodies were grounded for maintenance checks, the New Zealandic carrier wet-leased an A330-200 and an A340-300 from Hi Fly. The Portuguese ACMI/charter specialist also has an A330-300 and an A340-500 in its fleet.