An aircraft in flight is free to rotate in three dimensions. It is necessary to control the attitude or orientation of a flying aircraft in all three dimensions. In flight, any aircraft will rotate about its center of gravity, a point which is the average location of the mass of the aircraft. We can define a three dimensional coordinate system through the center of gravity with each axis of this coordinate system perpendicular to the other two axes. We can then define the orientation of the aircraft by the amount of rotation of the parts of the aircraft along these principal axes.
The yaw axis is defined to be perpendicular to the plane of the wings with its origin at the center of gravity and directed towards the bottom of the aircraft. A yaw motion is a movement of the nose of the aircraft from side to side. A positive yaw, or heading angle, moves the nose to the right. The rudder is the primary control of yaw.
The pitch axis is perpendicular to the yaw axis and is parallel to the plane of the wings with its origin at the center of gravity and directed towards the right wing tip. A pitch motion is an up or down movement of the nose of the aircraft. A positive pitch angle raises the nose and lowers the tail. The elevators are the primary control of pitch.
The roll axis is perpendicular to the other two axes with its origin at the center of gravity, and is directed towards the nose of the aircraft. A rolling motion is an up and down movement of the wing tips of the aircraft. The angular displacement about this axis is called bank. The pilot changes bank angle by increasing the lift on one wing and decreasing it on the other. A positive roll angle lifts the left wing and lowers the right wing. The ailerons are the primary control of bank. The rudder also has a secondary effect on bank.
In flight, the control surfaces of an aircraft produce aerodynamic forces. These forces are applied at the center of pressure of the control surfaces which are some distance from the aircraft cg and produce torques (or moments) about the principal axes. The torques causes the aircraft to rotate. The ability to vary the amount of the force and the moment allows the pilot to maneuver or to trim the aircraft
BASICS OF AERODYNAMICS
Aerodynamics is the study of forces and the resulting motion of objects through the air. Anything that moves through air reacts to aerodynamics. Here we only discussing about aircraft's aerodynamics.
FOUR forces of flight
A force may be thought of as a push or pull in a specific direction. A force is a vector quantity so a force has both a magnitude and a direction. When describing forces, we have to specify both the magnitude and the direction.
The AN/APG-77 is a multifunction Low probability of intercept radar installed on the F-22 Raptor fighter aircraft. It is solid-state, active electronically scanned array (AESA) radar. The APG-77(V) radar for the F-22 is based on the successful APG-66/68/80(V) family of fire control radars. It is a multifunction solid-state, active electronically scanned array (AESA) Low probability of intercept radar installed on the F-22 Raptor. It provides 120° field of view in azimuth and elevation. The active electronically scanned array (AESA) is a fixed, active array consisting of 1956 transmit/receive modules module low-power X-band transmit or receive modules that are electronically scanned or "steered," with no mechanical movement, each about the size of a gum stick. The separate transmitter and receiver for each radiating element results in increased agility, low radar cross-section, and wide bandwidth.
Its fast phase shifting and a lower level of energy is radiated by the side lobes, eliminating the spillover common to feed horn/reflector antennas. This makes the radar less detectable and reduces ground clutter. The APG-77(V) does not have a main processor of its own. Instead, two central integrated processors (CIPs), which can each process 700 million instructions per second with growth capacity up to 2,200 million, integrate the radar with other sensors and the electronic warfare systems on the F-22.