Abstract: A method of, and apparatus for, urging blades of a gas turbine engine radially outwardly is disclosed. The method may be used to grind blade tips of blades of a rotor stage of a gas turbine engine. The method comprises locating a fluid-tight bag which is in a radial gap formed between a radially inner surface of a respective blade root and a slot in a disc which the blade root cooperates. The method comprises inflating the fluid-tight bag and rotating the rotor stage relative to a grinding surface so as to grind any blade tips that contact the grinding surface during rotation. This results in more accurate positioning of the blades during the grinding process and/or during operation.

Abstract: A method of, and apparatus for, urging blades of a gas turbine engine radially outwardly is disclosed. The method may be used to grind blade tips of blades of a rotor stage of a gas turbine engine. The method comprises locating a fluid-tight bag is in a radial gap formed between a radially inner surface of a respective blade root and a slot in a disc which the blade root cooperates. The method comprises inflating the fluid-tight bag and rotating the rotor stage relative to a grinding surface so as to grind any blade tips that contact the grinding surface during rotation. This results in more accurate positioning of the blades during the grinding process and/or during operation.

Abstract: A liner wall insert is provided for a compressor rotor stage of a gas turbine engine. Several liner wall inserts are provided radially outboard of the tips of the rotor blades. The liner wall inserts have bleed flow channels formed therein. The bleed flow channels are arranged to remove flow from a trailing edge region of the stage and re-inject the bleed flow at an upstream region. The re-injected bleed flow alters the flow field around the tips of the rotor blades, for example the tip leakage flow. Thus, the bleed flow is used to improve the efficiency of the compressor rotor stage, and thus of the gas turbine engine.