Thrust vectoring
Subsequently, it was realized that using vectored thrust in combat situations enabled aircraft to perform various maneuvers not available to conventional-engined planes.
It is possible to generate pitch and yaw moments by deflecting the main rocket thrust vector so that it does not pass through the mass centre.
[5] A later method developed for solid propellant ballistic missiles achieves thrust vectoring by deflecting only the nozzle of the rocket using electric actuators or hydraulic cylinders.
The nozzle is attached to the missile via a ball joint with a hole in the centre, or a flexible seal made of a thermally resistant material, the latter generally requiring more torque and a higher power actuation system.
An effect similar to thrust vectoring can be produced with multiple vernier thrusters, small auxiliary combustion chambers which lack their own turbopumps and can gimbal on one axis.
The Sapphire and Nexo rockets of the amateur group Copenhagen Suborbitals provide a modern example of jet vanes.
Some smaller sized atmospheric tactical missiles, such as the AIM-9X Sidewinder, eschew flight control surfaces and instead use mechanical vanes to deflect rocket motor exhaust to one side.
[8] Some other projectiles that use thrust-vectoring: Most currently operational vectored thrust aircraft use turbofans with rotating nozzles or vanes to deflect the exhaust stream.
If an aircraft uses thrust vectoring for VTOL operations the engine must be sized for vertical lift, rather than normal flight, which results in a weight penalty.
Afterburning (or Plenum Chamber Burning, PCB, in the bypass stream) is difficult to incorporate and is impractical for take-off and landing thrust vectoring, because the very hot exhaust can damage runway surfaces.
The mechanical complexities of this design are quite troublesome, including twisting flexible internal components and driveshaft power transfer between engines.
Such nozzles are desirable for their lower mass and cost (up to 50% less), inertia (for faster, stronger control response), complexity (mechanically simpler, fewer or no moving parts or surfaces, less maintenance), and radar cross section for stealth.
Thrust-vectoring flight control (TVFC) is obtained through deflection of the aircraft jets in some or all of the pitch, yaw and roll directions.
[20] When vectored thrust control uses a single propelling jet, as with a single-engined aircraft, the ability to produce rolling moments may not be possible.
[27] While the Lockheed Martin F-35 Lightning II uses a conventional afterburning turbofan (Pratt & Whitney F135) to facilitate supersonic operation, its F-35B variant, developed for joint usage by the US Marine Corps, Royal Air Force, Royal Navy, and Italian Navy, also incorporates a vertically mounted, low-pressure shaft-driven remote fan, which is driven through a clutch during landing from the engine.
The Sukhoi Su-30MKI, produced by India under licence at Hindustan Aeronautics Limited, is in active service with the Indian Air Force.
[28] A few computerized studies add thrust vectoring to extant passenger airliners, like the Boeing 727 and 747, to prevent catastrophic failures, while the experimental X-48C may be jet-steered in the future.
The principles of air thrust vectoring have been recently adapted to military sea applications in the form of fast water-jet steering that provide super-agility.
