In a method for operating an engine, a request for an increase in thrust generated by the engine is received. In response to receipt of the request, a determination is made as to whether at least one operating condition for heat application-based thrust is met. If so, a heat source is applied to heat bypass air flowing through the bypass duct towards the exhaust nozzle and the increase in thrust is generated from an increased temperature of mixed bypass air and core air at the exhaust nozzle.