The 'Jump-jet' was the world's first vertical/short take-off and landing (VSTOL) operational jet aircraft. Developed using the revolutionary Pegasus engine, the Harrier has served the RAF and US Marine Corps well for over 30 years. Here, vividly told, is the fascinating story from the tentative hovering by the Hawker P1127 in 1960 to today's frontline Harrier GR9 and AV-8B warplanes.