Abstract: A stator assembly 14 includes an annular support structure, such as an outer case 24, and an element, such as a stator vane assembly 30. The stator vane assembly is restrained against circumferential movement by a key 58 integral with the stator vane which engages the outer case. Various construction details, including a radial projection 82 on the key, are developed which improve the fatigue life of the support structure and enhance the ease of assembly of the structure. In one method of assembling the structure, the method includes the step of using the radial projection on the key as an alignment device.

Abstract: Active clearance control is effectuated by heating the bore of the high pressure compressor spool so as to expand the compressor disc and labyrinth seals to minimize the gap between the blades and its peripheral seal and labyrinth seal. The high stages of the high spool compressor are selectively bled to achieve the desired gap control over the engine's operating envelope. The bled air is fed into the bore by conducting the air externally of the engine's case and admitting it through hollow stator vanes of the low pressure spool and tubes communicating with a cavity at the bearing supporting the high pressure compressor shaft at a juncture in line with the inlet of the high pressure compressor spool.