29

General Reasons There are three main reasons for having multiple ailerons per wing on large aircraft: Aileron Reversal On a large aircraft, at high speeds a deflected aileron can twist the wing enough to cause a net roll torque opposite to the one intended. The further out on the wing an aileron is, the more likely this problem is to arise. For high-...


29

The terms "slip" and "skid" refer to two different types of uncoordinated turn - neither has much to do with the elevator, instead both depend on what the rudder is doing: Skids In a skid you have too much rudder input for the turn - the aircraft starts to pivot into the turn. Because the aircraft is effectively pivoting about its center of lift while ...


25

Answer is yes, good eye. From the A380 flight crew manual: You can watch it here.


23

Short answer: Rudder and ailerons have different purposes and control rotation about two different axis, but their use is coordinated since a rotation about one axis induces a secondary rotation on the other one. The rudder use is mostly to prevent unwanted yaw movement for safety and comfort, or to force yaw against the aircraft tendency to keep the ...


21

That is an enclosure for a counterweight, either made from steel or lead to balance the aileron and/or reduce control flutter in various flight regimes. The extension provides an additional lever arm to alter the moment of inertia about the aileron’s axis of rotation. These are usually added or refined during flight testing to remove undesirable flutter or ...


17

Downward aileron travel must be restricted when flaps are deflected. Since flaps change the local incidence on the flapped part of the wing, the outer wing will experience an increase in its local angle of attack. The increased suction over the inner wing will accelerate not only the air flowing over the inner wing, but also that air which will flow over the ...


17

Yes the ailerons deflect upwards after main wheel touchdown to dump as much lift as possible: they work as lift dumpers, together with the spoilers which are deployed first. Source: an A380 pilot plus the FCOM. Update Just arrived on an A320, from could see both ailerons and they both deflect upwards as well after touchdown.


15

When you deflect the ailerons, you increase lift on one side of the wing and decrease it on the other. This causes a parallel increase of the local induced drag where lift is increased and vice versa. The consequence of that is a yawing moment which needs to be corrected with rudder deflection. Once your ailerons are neutral, this yawing moment goes away, ...


15

Bushings are a type of bearing that has no rotating parts. They are among the oldest bearings known. There is nothing special about it being for ailerons, except that is will be installed on the hinge of an aileron.


12

Flaps which only extend over part of the wing will cause lift changes mainly over that part of the wing, which will result in a lift distribution over span which is far from the elliptic ideal once the flap is deflected. Therefore, it makes sense to move the ailerons in the same direction, especially when the inboard flaps are simple camber-changing flaps. ...


12

Valse Des Ailerons (Waltz of Ailerons) or VDA is a nickname for the Load Alleviation Function (LAF) which is part of the flight control system. LAF uses all ailerons and spoiler 6 to 8 to alleviate the fatigue and static loads on the wings by reducing the wing bending moment. It consist of various sub functions dealing with passive load alleviation (based ...


11

This HD video of an A320 landing in Chicago shows that the ailerons move all the time during the approach, although the excitations are very limited from the moment the final flaps are selected. It seems there is some kind of limiting functions activated. Airbus has various versions of the aileron and spoiler control system on the A320 family. It is ...


11

First and foremost you should always be looking at the turn coordinator to see what is going on and applying rudder as necessary. In your specific case (if we want to discuss the physics), basically what your instructor is saying is that you are using the ailerons to bank (turn) the plane and the rudder to counteract the propeller's yawing moment. The ...


11

Yes it is a viable way for roll control - aerodynamically that is. The mechanism you describe is a proper servo tab, where the aeroforces on the tab are fed back, and the tab acts like a lever on the main control surface. This was the way the post WW2 airliners were controlled, before they got too big and fast and only hydraulics could do it. However, as ...


11

It depends on the aspect ratio of the wing and the lift coefficient. Short, stubby wings at low angle of attack will not create much adverse yaw with aileron input, especially when the ailerons have differential linkage (more deflection on the trailing-edge-up side and less on the opposite side). Differential gearing is also beneficial in reducing stick ...


11

The aileron itself doesn't stall, being part of the main wing. But since it alters the camber of the main wing it changes the local angle of attack in effect. On older airplanes, a down aileron at low speed could trigger a stall separation of the wing in the area of the aileron and if you applied aileron to correct a wing drop at the stall, it would just ...


10

If you know the rolling speed at a given flight speed, you can calculate the aileron effectiveness and use that to calculate the forces. The final rolling speed is reached when roll damping and the aileron-induced rolling moment reach an equilibrium: $$c_{l\xi} \cdot \frac{\xi_l - \xi_r}{2} = -c_{lp} \cdot \frac{\omega_x \cdot b}{2\cdot v_\infty} = -c_{lp} \...


10

You should just look at the ball and that will remove all doubt. If the ball is to the left, you use left rudder. It's that simple. After a while, like a couple hundred hours, you will start to feel when the aircraft is coordinated naturally, but until then just look at the ball. Don't fixate on it, though. Just glance down at some point when you are making ...


10

Any control surface changes both local camber and local incidence, so it would be best if you change the coefficients accordingly. If you use a panel code, it would be enough to change the local surface inclination (= the flow direction at the local control point) by the deflection angle. If you need formulas for the coefficients: A control surface with a ...


10

The ailerons, along with the spoilers are configured to act as lift dumpers on touchdown in most of the newer Airbus aircraft. This was introduced in the Elevator Aileron Computer ELAC standard L96, where, Aileron up deflection at ground spoiler extension becomes basic function.


10

For most aircraft, it is. Deflecting ailerons only results in adverse yaw: the aileron deflecting downwards has higher drag than the one deflecting upwards, and the nose turns away from the direction the pilot wishes to bank into. Image source The relative magnitude of this effect depends on wing span and airspeed: hardly noticeable in jet fighters, highly ...


9

Several good reasons depending on the design and intent of the aircraft: Mechanical simplicity. In your case of "flaperons", having a single set of control surfaces do two things decreases the number of moving parts the plane has. Simple is best; the simpler your aircraft, the less can go wrong (and the lighter it is, and when you're trying to get something ...


9

An Aileron is used to control the roll of an aircraft. Ailerons are found on the trailing edge of the wing, typically closer to the wing tip. Ailerons will move in opposite directions to each other, as one goes up, the other goes down. Flaps are used to increase the amount of lift that a wing produces by increasing the camber and surface area of the wing. ...


8

Ah that's a good question indeed. You asked How to reduce altitude in a passenger jet Normally most of the passenger jets have spoilers They are effective and can be deployed at any speed. Now what happens in case you don't have spoilers for any reason. I was discussing the subject with a pilot many years ago and he told me the trick you mentioned: you ...


8

You're correct that the ailerons are deflected differently when they are deflected up or down. This is done in order to counter the adverse yaw effect which occurs when ailerons are deployed. Consider the situation when the ailerons are deployed. Image from aerospaceweb.org One aileron is deflected downward while the other is deflected upward. One the side ...


8

There are already good answers, so I won't dwell on the standard advice to look at the slip indicator and do the necessary, but I'll answer to clear up a possible misunderstanding. You do not use rudder to correct for adverse yaw when turning. You use rudder to correct for adverse yaw when rolling into the turn. When you turn left, you put the stick left to ...


8

Given your request to "answer with less smart words," it's hard to know what knowledge can be assumed, but I'll give it a try. Let's say you're hand-flying the airplane straight and level, and you find that the right wing keeps wanting to drop, which you prevent by using left-aileron pressure on the control yoke. You can "trim out" the need for that left ...


8

On most general aviation airplanes, and other cable-controlled aircraft, they move together and for that matter are cross linked to the same physical cable. You can see this nicely on the control diagram for the B-24 (source) Some ailerons are designed to counteract adverse yaw and may move such that they are asymmetrical to the flow over the wing. 1) ...


7

I don't know the specific rationale in this case, but if you think about mechanical advantage, the farther an aileron is out from the center of gravity, the more roll effect will have on the airplane. You'll notice in the image that the outer aileron is deflected less than the inner aileron, even though they are probably producing roughly the same roll ...


7

As far as I know, the inboard ailerons are used for high speed maneuvering. The rolling moment induced by the ailerons is linearly dependent with the distance to the center of gravity (e.g. the farther out, the stronger the moment, the harder the roll). As the aileron is an aerodynamic surface, the force induces is equal to: $$F_{aileron} = c_l(\alpha) \frac{...


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