Can thrust vectoring reduce take-off/landing ( TO/L ) distance ?
At current time, there are two main methods to reduce TO/L distance -- for
FIXED WINGS aircraft:
- Speed. As in getting as fast as possible in as shortest a time as possible. The aircraft carrier catapult is an example of this.
On a land runway, on a normal take-off, the pilot increases throttle and hold down the brakes. At a certain point, engine thrust will overcome the brakes and the aircraft will begin to move regardless of the applied brakes. Pilots always release the brakes before this occurs. Then the aircraft begins to move forward and build speed. Eventually, the ground speed is enough where aerodynamics takes over and lift the aircraft off the ground.
On an aircraft carrier catapult, the catapult is essentially a powerful external force that overpowers the aircraft's engine(s) and propels the aircraft forward. This power is near instantaneous. That is why US Navy pilots braces themselves before catapult launches.
Can we use the catapult on land ? Yes. But why when we have all that land available ? Another method of producing a similar kind of near instantaneous power is the rocket, as in 'rocket assisted take-off' ( RATO ) where a bank of rockets overpowers the aircraft's engines and propels the aircraft forward.
-Thrust vectoring. As in using engine thrust other than longitudinal of the aircraft's main axis line. The famous Harrier is an example of this.
Here is an excellent source explaining how the Harrier uses TVC to reduce TO/L distance.
http://web.mit.edu/2.972/www/reports/harrier_jet/vectored_thrust_engine.html
...the rear thrust must be closer to the center of gravity of the aircraft and the front thrust farther from the center.
The Harrier's engine thrust are on
BOTH sides of the jet. There are
FOUR thrust nozzles. Two nozzles that are forward of center of gravity ( CG ). Two nozzles that are near CG.
The F-35's single engine uses a similar arrangement with a forward fan section and redirected rear thrust.
For an extreme, look at the helicopter. Its TO/L distance is zero. One hundred percent of engine thrust is used to literally lift the aircraft off the ground, then that thrust is redirected to move the aircraft forward. That is the famous body tilt usually exhibited by any helo after it is off the ground.
What this means is that we cannot simply install the F135 TVC into a regular F-16 and expect to have any beneficial reduction in TO/L distance. All we would do is lift the tail.
What I mean is, no single engine fighter jet uses TVC for post-stall maneuvering in the real world, V/STOL notwithstanding.
