Igniter for gas turbine engine

A gas turbine engine comprising:

• a casing;
• a combustor liner within the casing and spaced apart therefrom, the combustor liner delimiting a combustion chamber;
• a fuel nozzle in fluid communication with the combustion chamber for injecting fuel in the combustion chamber;
• and an igniter spaced apart and distinct from the fuel nozzle, the igniter having a base, a glow plug heater rod extending from the base along an axis and terminating in a rod end, and a sleeve annularly extending around the glow plug heater rod, an annular gap located radially between the sleeve and the glow plug heater rod relative to the axis, the glow plug heater rod radially spaced apart from the sleeve by the annular gap, the annular gap extending circumferentially around the glow plug heater rod, the sleeve defining a plurality of fins disposed circumferentially around the glow plug heater rod, each of the fins having a length extending axially along the axis, a width extending radially relative to the axis, and a thickness extending circumferentially relative to the axis, the length being greater than the width and greater than the thickness, the plurality of fins defining a plurality of spacings located circumferentially between the plurality of fins, the plurality of spacings configured to fluidly communicate with the annular gap such that the annular gap is in fluid communication with an environment outside the annular gap through the sleeve along a radial direction relative to the axis, the plurality of fins extending axially relative to the axis along at least a portion of the glow plug heater rod.