US Patent 11879350 Gas passage

A gas passage for a gas turbine engine, which allows for quicker and easier determination of the condition of a liner within the gas passage without the need for dismantling the entire gas passage, or irreparably damaging large sections of the liner. The gas passage comprises a casing with one or more plugs which are at least partly coated in a material matching the material composition of the lining, which can be removed from the gas passage in order to analyse the condition of the lining material.