Introduction

An operational supersonic Short Take-Off & Vertical Landing (STOVL) fighter has been the goal of several aircraft acquisition and development programs over the past forty years. Some of the most notable of these attempts have been the German EWR VJ 101C, the French Dassault Mirage III V and the Soviet Yakovlev Yak-141. Although each of these aircraft convincingly demonstrated vertical take-offs and supersonic speeds, none of them ever reached production, and history is littered with many attempts that either couldn't demonstrate supersonic STOVL capabilities or never left the drawing board. However, the desire for a supersonic STOVL fighter never ceased. Now, the vision of a supersonic STOVL fighter is finally materializing with the advent of the U.S.-led multi-national Joint Strike Fighter (JSF) program.

The JSF program began in 1994 as the Joint Advanced Strike Technology (JAST) program. JSF is developing an affordable family of next-generation strike fighters for the U.S. Navy, Air Force, and Marine Corps, the UK Royal Navy and Royal Air Force as well as the armed services of several other U.S. allies.

Initially, four contractors were involved: Boeing, Lockheed, McDonnell Douglas/British Aerospace and Northrop. In late 1994 Northrop joined the McDonnell Douglas/British Aerospace team. Based on concepts under study for the Defense Advanced Research Projects Agency (DARPA) Advanced STOVL program, the four contractors began developing concepts for the JSF STOVL variant. Boeing proposed using a vectored thrust system, somewhat similar to the one in use on the Harrier Jump Jet. Lockheed proposed using a shaft-driven lift fan. McDonnell Douglas/British Aerospace originally was studying a gas-driven lift-fan configuration. Northrop opted for a lift-plus-lift/cruise configuration similar to the one used on the Yak-141. When McDonnell Douglas/British Aerospace teamed with Northrop, they kept the lift-plus-lift/cruise configuration.

On 16 November 1996, the Secretary of Defense announced that Boeing and Lockheed Martin would continue into the Concept Demonstration Phase (CDP). Pratt & Whitney (P&W) also moved forward into CDP to develop the propulsion system, with General Electric (GE) developing an alternate engine.