EWR VJ 101 the VJ 101C did not proceed to production status, various other projects of the era to develop supersonic-capable VTOL fighter aircraft, including the Mirage IIIV and the Hawker Siddeley P.1154 (a supersonic parallel to what would become the Hawker Siddeley Harrier, a subsonic VTOL combat aircraft that reached operational service), ultimately met similar fates. The Harrier jump jet and, substantially later, the Lockheed Martin F-35 Lightning II, has since demonstrated the potential of VTOL fighters. EWR VJ 101 The EWR VJ 101 was an experimental German jet fighter vertical takeoff/landing (VTOL) tiltjet aircraft. VJ stood for "Versuchsjäger", (German for "Experimental
Hawker Siddeley Harrier testing. The two remaining British-based Kestrels were assigned to further trials and experimentation at RAE Bedford with one being modified to use the uprated Pegasus 6 engine. At the time of the development of the P.1127 Hawker and Bristol had also undertaken considerable development work on a supersonic version, the Hawker Siddeley P.1154, to meet a North Atlantic Treaty Organisation (NATO) requirement issued for such an aircraft. The design used a single Bristol Siddeley BS100 engine with four swivelling nozzles, in a fashion similar to the P.1127, and required the use of plenum chamber burning (PCB) to achieve supersonic speeds.