The first flight of the COMAC C919 has marked the debut of Nexcelle’s engine nacelle system, which provides improved operating performance and efficiency, lower weight and easier maintenance for the twin-engine Chinese jetliner’s integrated propulsion system.
The C919 nacelle system – developed with expertise from the Nexcelle 50/50 joint venture’s two parent companies, Safran Nacelles and GE Aviation’s Middle River Aircraft Systems – is incorporated on the C919’s LEAP-1C turbofan engines, developed by CFM International.
Nexcelle president Kenneth Onderko commented: “Our parent companies’ know-how in design, integration and manufacturing have contributed to the highly-capable nacelle system that is now flying on the C919. The result is a tribute to the dedication and professionalism of the teams at Middle River Aircraft Systems and Safran Nacelles, who have overseen its smooth development.”
Key features of Nexcelle’s nacelle system for the LEAP-1C include an all-new translating O-Duct thrust reverser configuration; a fan cowl that is structurally integrated to the engine; and an integrated mounting system for reduced engine distortion and enhanced on-wing performance.
A major innovation in Nexcelle’s nacelle design is its one-piece composite O-Duct thrust reverser configuration, which replaces the two-piece “D” doors on traditional thrust reversers. When deployed, the O-Duct moves aftward to the reverse thrust position, eliminating drag links in the engine’s secondary flow-path, enhancing the airflow path and improving fuel consumption – while also increasing thrust reverser efficiency.
The O-Duct deployment is performed with an evolved electrical thrust reverser actuation system (ETRAS), replacing heavier hydraulics typically used in thrust reversers and improving maintainability.
Another of the nacelle system’s technological advances is its low drag front end that incorporates an air inlet with a one-piece lip skin – the largest of its kind to enter production on a large commercial jet engine, improving airflow and contributing to lower noise.
Additionally, the inlet has a directed flow nozzle deicing system, which more efficiently swirls engine bleed air within the inlet lip, thereby providing weight, efficiency and maintainability improvements from traditional nacelle deicing systems.
Nexcelle’s LEAP-1C nacelle also incorporates the extensive use of lightweight and state-of-the-art noise-attenuating composite materials, benefitting from the joint venture parent companies’ proven experience in their respective nacelle and thrust reverser product lines.
In developing the nacelle system, Nexcelle worked closely with CFM International, which itself is a joint venture of GE Aviation and Safran Aircraft Engines. The result of this collaboration is one of the first truly integrated propulsion systems for the air transport sector.
The C919 performed its maiden flight from COMAC’s Shanghai Pudong International Airport facility, where Nexcelle’s on-site team has been supporting the nacelle system through the development phase, and has been reinforced for the C919’s flight test campaign and industrialization phase. Nexcelle’s O-Duct thrust reverser was utilised during the jetliner’s first landing, demonstrating its performance from the startup of C919 flight testing.