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15

It is a combination of several effects: Aeroelasticity: With the higher forces at high speed, the structure deforms such that the effective flow angle at the tail surface is reduced. The supersonic lift curve slope of the tail surface decreases with Mach while that of the fuselage stays roughly constant, so with higher Mach the tail contribution to ...


5

Yes. For deliberate cross control situations, adverse yaw helps. This means during side slip or forward slip maneuvers, where adverse yaw means less rudder is required to keep the nose pointed in the opposite direction to the lowered wing. If you are in a glider or an old classic aircraft with lots of natural adverse yaw, if you lower a wing without any ...


4

Because: Here you see a fuselage viewed from above. The horizontal line at the right end of the ellipse is the tailfin. On top is a subsonic plane, and at the bottom is a supersonic one. The thin lines are pressure, the thick ones are forces, and the arrows show flow direction and magnitude. As you can see, at subsonic speeds suction is more dominant, ...


4

Rate of turn is easy to define: it is the rate at which the direction of aircraft motion changes with respect to the ground (rate of change of track). If the aircraft is not slipping and there is no change in wind, then it is equivalent to the rate of change of heading. Yaw rate, on the other hand, is slightly messier. Technically, yaw rate of the rate of ...


3

Turn rate is the rate at which an aircraft's direction of motion changes. Yaw rate is: If the aircraft is wings-level: the rate at which an aircraft's heading (the direction in which the aircraft's longitudinal axis points) changes. If the aircraft is not wings-level: the rate at which the aircraft's heading would be changing if the aircraft were wings-...


2

The rudder of A320 is fully mechanical. So, the control laws do not govern its movements. In normal operations, the rudder is controlled by FAC (Flight augmentation computer) and it gives three main functions. They are: Yaw damping and turn coordination. Rudder travel limiting through the rudder travel limiter (controls the rudder deflection angle based on ...


2

Lifting Line analysis is not suitable for low aspect ratio wing, highly swept wing or a wing undergoing large sideslip, because each of these would have significant spanwise flow gradient. To see why, it's worth revisiting the central equation of the Lifting Line, applicable to a planar wing: $$c_l(y)=a_0 \left[ \alpha - \frac{w(y)}{V_\infty} - \alpha_{L=0} +...


2

When the rudder is deflected, it creates a "lift" on the vertical tail due to additional camber. This "lift", when viewed from the airplane perspective, is a side force opposite to the direction of the rudder deflection. Since the centre of pressure of this side force is aft of the centre of gravity, it generates a net yaw moment on the airplane. For ...


1

If you press the right rudder pedal, the rudder will deflect to the right (starboard) side of the plane. This action will deflect the relative wind towards the right-side of the airplane much the same as if you were to turn the entire vertical stabilizer counter-clockwise. This deflection to the right generates a force acting towards the left. The tail will ...


1

This is a comparison of two frames of reference: turn rate is earth referenced on a horizon based yaw plane, whereas aircraft yaw rate is based on the aircraft yaw plane. In a skidding turn with no bank, they would be equal. In a 90 degree "bank and yank" or "knife-edge", the rate of turn is 100% in the pitch plane, with 0 yaw. A coordinated turn is a ...


1

A very simple explanation here. Turning the rudder to the right is initially very similar to turning the rear tires of a forklift to the same direction. It will make the plane tail pull left and creates the yaw. Of course soon the similarity ends because of the interplay of fuselage with the wind and the fact that rudder forces want to roll the plan ...


1

The rudder, being a vertical variable camber wing, applies a left lift force when displaced right. The left lift force yaws the plane right and also applies a force trying to slew the plane to the left. The yaw results in the relative wind striking the side of the fuselage, creating a certain amount of lift to the right, depending on how effective an ...


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