PWA111771 is a high-performance turbine disk seal ring developed by Pratt & Whitney, designed for the PW4000 series turbofan engines used in large commercial aircraft such as the Boeing 777 and Airbus A330. It functions as a dynamic sealing component between the turbine disk and the engine casing, minimizing the leakage of high-temperature exhaust gas between turbine stages, which is essential for maintaining the turbine's energy conversion efficiency and reducing unnecessary energy loss during engine operation.

Fabricated from a heat-resistant, wear-resistant nickel-based superalloy, it can endure operating temperatures up to 1,050°C and the intense centrifugal forces of high-speed turbine rotation. Complying with AS9100D quality standards and FAA requirements, the 0.21kg component features a precision-machined sealing face, enabling quick inspection and replacement during MRO processes, and is a key part for ensuring turbine operational stability.