This got to be the most outrageously tight turn by J-20, I have seen yet. It did a 180 degree U-turn in about 3-4 seconds. It literally just flip around at the bend of the U shape, which lasted about 1 second.
This one is done with the usual deep banking like other airplanes.
What really happens if an aircraft tries to change heading via rudder only, aka the non banking method.
http://www.empire-aviation.com/flight-instructors/john-e-mclain/understanding-the-use-of-rudder.html
The right wing is now advancing into the relative wind, and the left wing retreating.
This means the right wing is generating more lift than the left wing, which results is a roll to the left, even though the ailerons are neutral.
This kind of asymmetric lift is found on one type of aircraft -- the helicopter. One blade travels forward while its opposite travels aft. This is why piloting a helo requires different sets of instructions and the helo pilot develops completely different sets of skills.
The J-20 is a delta winged aircraft. So what really happens to the delta wings if such an asymmetric airflow and lift exists on them ?
https://www3.nd.edu/~rnelson/Unsteady Vortex Flows.pdf
The unsteady motion of the delta wing results in a modification of the flow field. Delays in flow separation, vortex formation, vortex position and the onset of vortex breakdown are all affected by the model motion. These flow changes cause a corresponding modification in the aerodynamic loads.
If the flow separates asymmetrically on one wing, as shown in Fig. 3, then a rolling moment is created.
For the highlighted, it means the delta winged aircraft will spin out of control.
Is there another method to execute a non-banking turn ?
Yes, the B-2's wing tip split ailerons method.
In the above photo, the B-2's wing tip split ailerons are clearly visible. Essentially, they are airbrakes, which creates drag.
The wing tip drag method does not rotate the aircraft on its vertical (yaw) axis. It is not that difficult to envision the differences by way of a straight ruler. Spin the ruler on its center. Then hold one end while moving the other end.
Even so, the only time the B-2 would use split ailerons as the
SOLE turning method is when its 'stealthy' flight is paramount, as in penetrating enemy airspace. Otherwise, the B-2 would use the banking method to change heading. Adverse yaw kills.
For what Mr. Asok is trying to peddle, the J-20 must have extraordinary flight control surface range of movements and coordination software beyond anything available, commercial and military. For a delta wing-ed platform, this probably defies a few laws of aerodynamics.
Why is doing a tight turn without deep banking useful in a dogfight?
When the pilot doing a tight turn with deep banking, his head is point to the center of the turn, and the blood is pulled by the centripetal force toward his legs. At sustained high G, the pilot is prone to blackout (lost of consciousness), or greyout (lost his vision), because of lack of blood flow to his head. Also he will be having a hard time to keep his opponent in his sight. His head will be very heavy and turning of his head will be very difficult. He will have a hard time to follow his opponent, around the turn, long enough to get a good lock, to fire his weapon, with his Helmet Mounted Sight.
When you turn without the need of deep banking, you don't have those problems as much. You will be sitting horizontal, with your head up, like driving a car, around a turn. You will be pushed toward the window, instead of toward the floor by the G-force. Your blood will not be pull toward the floor or legs as much, so your tolerance to high-G force will be much greater. And your head will be much easier to turn, and able to watch your opponent over your shoulder, and aim your weapon using your HMS.
Sure.
Except for the uncomfortable fact that in racing, drivers secures their helmets with chains because the g-forces generated under
2-D maneuvers can be enough to break necks. That is adverse yaw working. Pilots do not need to chain their helmets is because of the direction of the generated g-force when executing banking turns.
What Mr. Asok is peddling is -- once again -- the J-20 defies the laws of physics.