VFW Fokker VAK-191B

The VAK concept of NATO and the German Armed Forces required an aircraft that was able to take off from unprepared airfields without runways. Its mission was close air support. In addition it had to be able to fly long distances in extreme-low-altitude in order to prevent attacks of antiaircraft weapons and radar detection. Because of this the VAK was designed with short wings and a minor extension so it would provide its pilots a tolerable flight and bear aerodynamically difficult extreme low altitude flights.
The first prototype flew on September 10, 1971, powered by one 10,150-lb (4604-kg) thrust Rolls-Royce/MTU RB.193 vectored-thrust turbojet and two 5577-lb (2530-kg) thrust RB.162 lift turbojets. It had small, vertically mounted jets in the front and rear of the fuselage for direct lift, plus a third engine of the vectored -thrust type for forward propulsion and transitions between horizontal and vertical flight. It uses "puffer-jets" at the nose, tail and wingtips to stabilise it during low-speed and hovering man-oeuvres. In terms of design, it is intended for experimental work only.
The first transition - the transfer of vertical flight in horizontal and vice versa as well as turning off and on the lift-engines - was achieved on October 26, 1972 in Manching, Bavaria, at a speed of 400 km/h.
All three VAK 191B experimental aircraft completed a total of 91 flights that lasted all together 12 hours.

Despite successful flight trials it was not ordered into production as the Harriers of RAF Germany were already fulfilling the need for which the VAK-191B had been conceived.

VAK 191B
Engines: 1 x Rolls-Royce/MTU RB 193-12, 45.2kN + 2 x Rolls-Royce RB 162-81 F 08, 26.5kN
Max take-off weight: 8507 kg / 18755 lb
Empty weight: 5562 kg / 12262 lb
Wingspan: 6.16 m / 20 ft 3 in
Length: 14.72 m / 48 ft 4 in
Height: 4.30 m / 14 ft 1 in
Wing area: 12.5 sq.m / 134.55 sq ft
Max. speed: 1100 km/h / 684 mph
Cruise speed: 740 km/h / 460 mph
Range: 400 km / 249 miles
Payload: 2945kg
Crew: 1