Gas turbine engine liner

A liner for a gas turbine engine is provided that includes a first liner section 30 and a second liner section 32. The first liner section 30 includes a first flange 34 having a first contact surface 36. The second liner section 32 includes a second flange 47 having a second contact surface 44 and a plurality of apertures 46. The first and second flanges 36,42 axially overlap one another, and in a circumferential liner the second flange 42 is disposed radially outside of the first flange 34. A channel 48 is formed by the two liner sections that is open to the core gas path. In a first position, the first flange 34 axially overlaps the second flange 42 by a first distance and the apertures 46 are misaligned with the first flange 34 and disposed within the channel 48. Cooling air entering apertures 46 within the second flange 42 subsequently passes into the channel 48. In a second position, the first flange 34 axially overlaps the second flange 42 by a second distance. The second distance is greater than the first distance and in the second position the apertures 46 in the second flange 42 are substantially aligned with the first flange 34. Cooling air entering the second flange apertures 46 subsequently impinges on the first flange 34.