Aircraft maneuverability. Aircraft handling and stability.

The maneuverability of the aircraft - is its ability to change over time its position in space (direction, speed and altitude), t. E. To make evolution to maneuver in the air. Manoeuvring characteristics of aircraft depend on several factors: the aerodynamic and strength limitations, the available thrust engines, flight weight, and others. The operational flexibility of the aircraft is defined by its handling, engine response, the speed of switching reverse thrust, speed flap, flaps, spoilers.

Controllability of the aircraft - is its ability to change the mode

by the will of the pilot's flight (with its rejection of the controls). This motion control levers should be simple and be accompanied by a small, but good for them to feel the effort.

The stability of the aircraft - the ability of its own, without the intervention of the pilot to maintain the specified flight mode and return to the original equilibrium after the termination of external disturbances. In other words, sustainability, by definition, NE Zhukovsky, can be understood as "strength" of balance.

The aircraft must be stable with respect to all three axes. The good characteristics of stability necessary for the better handling of the aircraft. In simpler sustainable aircraft movement control levers and less total expenditure of the nervous and muscular energy management pilot.

For the convenience of consideration of the stability of conventionally divided into static stability - the property of the aircraft to detect a tendency to restore the disturbed balance of the initial time and dynamic stability - property of a plane without a pilot action to restore the original mode of flight some time after the termination of the disturbance.

The presence of static stability is a necessary but not sufficient condition for the dynamic stability of the aircraft.

Longitudinal static stability is divided into overload resistance - the ability of the aircraft on their own, without the intervention of the pilot, to keep reloading the original flight regime and the stability of the speed - the ability of the aircraft on their own, without the intervention of the pilot to keep the speed of the original flight mode.

In the case of flight with the aircraft sliding track having (with respect to the axis O y) and transverse (relative to the axis Ols) static moments. The plane, which has a track (feathered) resistance that occurs during sliding moment tends to destroy the slip. At the lateral stability of the aircraft occurs when sliding moment tends to bank the plane in the direction opposite to slip. Heeled aircraft causes a reversal in the direction of the roll and facilitates thus the destruction of the slip.

Directional stability of the aircraft is provided mainly by the vertical tail surfaces. The larger the area of ​​vertical surfaces (keel forkil, washers, combs, etc.) And the more shoulder surfaces of the center of gravity of the aircraft, the better directional stability of the aircraft.

Lateral stability is provided by the aircraft angle V-wing cross and the height of the keel. The greater the angle of the wing cross-V and the higher the keel, the better the transverse stability of the aircraft. Increased sweep wing also improves lateral stability of the aircraft.

In aircraft with swept wings lateral stability is largely dependent on the angle of attack, increasing as it is increasing.

The plane with a high degree of lateral stability is responsible energetic kreneniem the occurrence of slip. If excessive lateral stability becomes much more complicated in the case of piloting the flight in turbulence and in the event of asymmetric thrust.

However, the pilot basically assesses not the manifestation of lateral and road stability separately, but their combination. The simultaneous manifestation of the track and lateral stability is considered as the lateral stability of the aircraft. Lateral stability provides a certain relationship between track and transverse stability. 

For large values ​​of y, the behavior of the aircraft is assessed as unsatisfactory, that is, the occurrence of slip is accompanied by a sharp inclination and, as a result, by the plane's razbaltyvanie. The aircraft alternately heels and prowls from side to side. 

Chord conditional rectangular wing having at equal angles of attack similar to the wing of the airplane under consideration value of the total aerodynamic force and longitudinal moment is called the mean aerodynamic chord (MAR). The size and position of the MAR for each aircraft specified in the datasheet.

Since the aircraft in the air rotates around the center of gravity, the center of gravity (centering) has significant influence

Log out alignment of the set for the type of aircraft range is invalid. Excessive movement centering ago (set limit) will cause deterioration of the stability of the first aircraft overload and then can lead to instability. However, excessive forward center of gravity makes it difficult to control the aircraft and can lead to "a lack of steering" on landing.