A method of monitoring turbine blade creep in a gas turbine engine is provided. The method includes: receiving an image of a turbine blade of a row of turbine blades, the image having been obtained using a borescope located in the engine adjacent a row of turbine blades; measuring on the image a distance between radially inner and radially outer landmarks on the turbine blade; and comparing the measured distance with a reference distance to determine an amount of creep-induced lengthening of the blade.