Abstract: Asymmetric distortion between an inner casing and outer casing such as with regard to a gas turbine engine between an inner high pressure compressor casing and an outer combustion casing can result in problems with regard to rub between a rotary assembly within the inner casing. By providing hairpin mountings between the inner casing and outer casing such distortions can be dislocated. Individual hairpin segments are provided. These hairpin segments can be configured and formed from different material types and have different spacing distributions to tune the casing arrangement to the particular requirements and operational performance necessities of an assembly incorporating the casing arrangement.

Abstract: A fan outlet guide vane assembly (36) for a turbofan gas turbine engine (10) comprises a fan casing (32) and a plurality of circumferentially spaced radially extending fan outlet guide vanes (34). The fan outlet guide vanes (34) are secured at their radially outer ends to the fan casing (32). A plurality of panels (40) are secured to the fan casing (32). Each panel (40) is arranged between two adjacent fan outlet guide vanes (34) to define the flow path between the fan outlet guide vanes (34). Each panel (40) comprises a perforated skin (42) and a honeycomb structure (44) to form an acoustic treatment structure. The perforated skin (42) defines the flow path between the fan outlet guide vanes (34). The pressure equalization across the panels (40) minimises the possibility of the panels (40) being removed.

Abstract: A fan outlet guide vane assembly (36) for a turbofan gas turbine engine (10) comprises a fan casing (32) and a plurality of circumferentially spaced radially extending fan outlet guide vanes (34). The fan outlet guide vanes (34) are secured at their radially outer ends to the fan casing (32). A plurality of panels (40) are secured to the fan casing (32). Each panel (40) is arranged between two adjacent fan outlet guide vanes (34) to define the flow path between the fan outlet guide vanes (34). Each panel (40) comprises a perforated skin (42) and a honeycomb structure (44) to form an acoustic treatment structure. The perforated skin (42) defines the flow path between the fan outlet guide vanes (34). The pressure equalisation across the panels (40) minimises the possibility of the panels (40) being removed.