Annulus filler

An annulus filler for mounting to a rotor disc of a gas turbine engine and bridging the gap between two adjacent blades attached to the rotor disc, the annulus filler being substantially entirely formed from a polymer matrix composite material, and the annulus filler having:

• an outer lid which defines an airflow surface for air being drawn through the engine in an axial airflow direction, and
• a support structure which is connectable to the rotor disc to support the rear of the lid on the rotor disc, the support structure having two support walls extending from opposing lateral sides of the lid to an attachment strap for receiving a hook on the rotor disc, the attachment strap bridging the support walls, and, in use under centrifugal loads, the support walls resiliently deforming to allow outward radial movement of the lid;
• wherein each support wall has a concave rear edge which extends rearwardly and radially outwardly from the rear of the attachment strap towards a trailing edge of the lid, each rear edge having a first curved section proximal the attachment strap, a second curved section proximal the trailing edge and a substantially straight section therebetween, and
• the attachment strap is integrally formed with the composite material of the support walls.