A fan track liner assembly for ducted fan engine which provides for reduced strain and deformation of front of fan case in the event of a fan blade off event. Various assemblies are proposed. In one aspect, assembly includes fan track liner panel and plurality of fasteners which are arranged to secure panel to fan case of engine, wherein: a forward portion of panel includes hinged portion which operates as trapdoor to permit blade or blade fragment to pass through, and fasteners are arranged to fail in the event of blade or blade fragment passing through trapdoor causing panel to be displaced rearwards in fan case. Other aspects provide for reduced height of support on fan case for attaching fan track liner and for collapsible comb box.