Boeing 787 operators struggling with Rolls-Royce engine issues have suffered a further blow after the FAA limited overwater operations for aircraft powered by certain Trent 1000 engines.
In an airworthiness directive aimed at 787-8/9 aircraft with Package C variants of the engine that have completed more than 300 cycles, the FAA limits operations to a maximum of 140 minutes’ flying time from the nearest diversion airport.
The FAA’s previous limit was 330 minutes.
The new AD took effect on April 17. Justifying it, the FAA said it was concerned about failure of intermediate pressure compressor stage 2 blades.
Tests have shown that the blades have a resonant frequency that is excited by airflow conditions during operation at high thrust settings under certain temperature and altitude conditions, which can lead to cracking and failure.
In the event of failure of one engine, the remaining powerplant would typically operate at the maximum thrust setting for a prolonged period, until a diversion airport is reached. By reducing this period, the FAA aims to lower the risk of failure in the other engine.
The FAA’s AD followed one by EASA requiring accelerated inspections of the compressors of roughly 340 Package C engines.
Following those inspections, Air New Zealand reported that it would have to remove two 787s from service to await engine repairs at Singapore Aero Engine Services, a joint venture between Rolls-Royce and Singapore Airlines.
However, the airline said that due to “very high demand on Rolls-Royce’s maintenance facility” given the number of engines affected globally, “it may take a number of months before Air New Zealand’s engine repair work can be completed.”