This specification established the requirements for a 5 second duration, 4500 pound thrust (when determined at 60 mDF) solid propellant rocket engine hereinafter specified as 5 S-4500.The 5 S-4500 rocket engine is a moderate duration, low- thrust, self-contained power plant employing a solid propellant. The engine is designed specifically for jet assist take-off (JATO) of aircraft, and to deliver a nominal thrust of 4500 pounds for 5 seconds duration at 60mDF and sea level. The engine contains aircraft attachment fittings and an ignition system.