Abstract: The casing assembly comprises a casing comprising a slot defined by a front surface and a rear surface, the front surface and the rear surface being spaced apart by an axial casing gap. A plurality of stator vanes comprising a platform and at least one aerofoil extending from the platform, the platform being received within the slot and having an axial length and a circumferential length. Circumferential lengths of the platforms define a total circumferential length which is less than the circumference of the casing at an outer radial surface of the platforms and so defines a circumferential clearance. Axial length of each of the platforms is less than the axial casing gap and so defines an axial clearance. Circumferential and axial clearances allow the platforms of the stator vanes to rotate within the slot, with rotation of the platforms from an unrotated position reducing the circumferential and axial clearance.