A liner panel, such as a cassette 120 of a fan track liner of a gas turbine engine, is secured to a casing of the engine at flanges 124 and 126. Foam pads 42 are disposed between the casing 40 and the cassette 120 to support the cassette 120 from the casing 40. The pads 42 may be made from a reticulated polyurethane foam which is sufficiently resilient to be compressed and to expand to remain in contact with the cassette 120 and the casing 40 as the cassette 120 moves towards and away from the casing 40 during the assembly process. The foam is impregnated with a hardener composition which is uncured during installation of the cassette 120, but subsequently cures to increase the rigidity of the pads 42.