A sacrificial outer sleeve of a self-eroding single-use gas-turbine-engine igniter contains a main pyrotechnic composition and an initiator embedded therein proximate to a distal portion of the sacrificial outer sleeve. The sacrificial outer sleeve extends within a combustion chamber of the gas-turbine engine when operatively coupled thereto so as to provide for igniting a fuel/air mixture therein. The sacrificial outer sleeve is constructed of a material that is consumable either responsive to combustion of the main pyrotechnic composition responsive to activation of the initiator responsive to an actuation signal communicated via an associated signal conduit, or, responsive to a subsequent operation of said gas-turbine engine to which the igniter is operatively coupled, when operatively coupled thereto.