The Rolls-Royce Avon is a turbojet engine developed in the 1950s, primarily used in military aircraft. It was known for its reliability and performance, powering various planes, including the Hawker Siddeley Buccaneer and the English Electric Lightning. This engine features a single-spool design and was one of the first to utilize a bypass system, enhancing efficiency. The Avon played a significant role in the evolution of jet propulsion technology and contributed to the advancement of aviation during its time.