The tests included operating the nozzle in full afterburner with the nozzle deflected ninety degrees. The first nozzle was built and tested on a Pratt & Whitney JT8D in the mid 1960s. Design drawings dated 1967 show detail design layouts. The US Patent Office received applications for many variations of the 3BSD from Pratt & Whitney, General Electric, and even from Boeing Military Aircraft of Wichita, Kansas.īy the late 1960s, Pratt & Whitney was designing and testing a three-bearing swivel nozzle for use on the Convair Model 200 Sea Control fighter. Three-bearing swivel nozzle designs were studied by virtually all of the engine companies in the mid 1960s. Various combinations of numbers and locations of engines were built and flown on several VTOL prototypes and experimental aircraft.

Allison, Rolls-Royce, and other engine manufacturers developed compact turbojet engines specifically for such applications.

These designs were called Lift Plus Lift/Cruise. The most popular solution was to add small lift engines just aft of the cockpit to provide vertical thrust forward of the aircraft center of gravity. This dual operational approach led to larger, heavier aircraft designs that needed more vertical thrust than could be provided by just the primary engine or engines. The Navy’s concept of operations would also require these aircraft operate as traditional carrier-launched fighters, which necessitated afterburning engines. These proposed fighters would take off vertically with full loads. US Navy studies in the 1960s evaluated Sea Control VTOL aircraft designed to operate from ships with smaller decks than from decks on traditional aircraft carriers. Meanwhile, only the Yak-38, which used a similar engine and nozzle arrangement to the Harrier, saw service on the Russian side. However, only the British Kestrel/Harrier family made it into service. The United States, United Kingdom, Germany, and France all built and tested multiple VTOL fighter designs. Such aircraft, secured in hardened shelters, could still take off and land from bases with damaged runways. Interest in designs for vertical takeoff and landing, or VTOL, fighter aircraft began in the 1960s at the height of the Cold War when NATO bases were seen as vulnerable to preemptive attacks.

The nozzle also provides yaw control during hover and during transitions to hover. The 3BSD can move through ninety-five degrees of motion seamlessly with no change in engine operation. The nozzle, mounted at the back of the aircraft, allows the thrust from the Pratt & Whitney F135 engine to be vectored from straight aft for conventional flight to straight down for STOVL operations. A critical component of the F-35B short takeoff/vertical landing, STOVL, variant of the Lightning II is the three-bearing swivel duct nozzle, or 3BSD.

F 22 lightning 3 drawing