A method and apparatus for rapidly severing a decoy towline extending from an aircraft by a mechanical spring actuated cutting blade and a thermal fuse type of release mechanism eliminating a pyrotechnic actuation device. The cutting blade is biased toward cutting engagement with the towline by a preloaded coil compression spring retained in the loaded position by a length of a polymer cord. The polymer cord has a heater wire wrapped about a portion of the cord which is connected to a DC voltage supply. The heater wire melts the cords when electrically connected to the DC power supply which releases the restraint on the spring which then drives the cutting blade into severing engagement with the towline.