# Tag Info

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The maximum useable deflection angle depends on the relative chord of the control surface. A good first-order value is ±20° for a 20% chord. With increasing chord, the deflection range will become smaller, like ±15° for a 30% flap. With ailerons, things are a bit different because they are part of a lifting surface. This gives them some pre-loading so the ...

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There is no concrete answer for this. It all depends on aircraft, airspeed, air density, attitude, configuration, wing loading, and weight. For example, a Piper Archer at cruise airspeed in straight, level, unaccelerated flight will have very little deflection necessary in flight controls to change or maintain attitude of flight. As you transition to slow ...

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This is thinking a little "outside the box", but one thing you could do is use to the internet to locate some manuals for some ready-to-fly radio-controlled model airplanes such as those produced by HobbyZone, etc. The manuals will typically list "low rates" and "high rates" for each surface. The "low rates" have to provide the minimum control throw that ...

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For the B737NG, the pilot stick inputs are transferred to hydraulic actuators, via mechanical (steel) cables. For example for the Power Control Units of the ailerons, as also depicted in this question: The site where the image came from also lists a schematic pic for a fly-by-wire setup. There is still a hydraulic actuator but no more steel cable loop to ...

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Indeed the hinge moment equation is (with index $_s$ for surface) $$H_s = C_{h_s} \cdot ½ \rho V^2 \cdot \delta_s \cdot S_s \cdot \bar{c_s}$$ The moment coefficient $C_{h_s}$ depends on aircraft angle of attack, surface deflection (!) and trim tab deflection, as depicted in the figure below (from this answer). It is not a simple constant linear function ...

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From this answer: The servo tab is an aerodynamic lever. It is connected directly to the pilot flying controls. The trim tab has a constant angle relative to the control surface. The angle can be changed by extending/retracting a mechanical link, via a trim wheel or an electric motor with a screw jack. Seen from outside, the tabs look pretty similar....

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From an old uni book on stability & control of aeroplanes, showing the pressure distribution over the horizontal tail: First picture: no elevator or trim tab deflection, pressure peaks at the stabiliser nose at two different Angles of Attack $\alpha_h$. Two different elevator deflections $\delta_e$: pressure peaks at the elevator profile nose. Two ...

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1. Aeroelasticity Unlike a tailplane, a delta wing is more rigid due to its much bigger chord and multiple spars, so control reversal due to aeroelasticity isn't a special concern. Big subsonic jetliners typically lock the outer ailerons at high speeds. Concorde featured a similar function for the outer elevon, but only if $V_{MO}$ is exceeded by 25 knots ...

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Well, both. Lift can be described as a moving wing colliding with air molecules at an angle, the result of the collision is the wing moves one way and the air mass the other, as per momentum physics. Moving the trailing edge, or the entire surface, increases the angle of attack, resulting in more lift at a given speed $V$: $Lift$ = 1/2 × Lift Coefficient ...

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Thankfully, aerodynamics in the usual flight range is linear. Therefore, there is a gradient of lift over angle of attack and another one over the flap deflection angle. Both are constant over a range of maybe ±15° and can be combined. The angle of attack is referenced to the fixed part of the flight surface and the deflection angle to the moving part ...

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A trailing-edge control surface, when it deflects, changes the camber of the overall airfoil. More camber means more lift, in whatever direction that airfoil is mounted. In your example, adding up elevator increases the horizontal stabilizer's camber, which increases the downward force it applies. Philosophically, "why" it does this is just, well, that's ...

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Different aircraft and manufacturers take very different approaches. 1. Boeing 777 The B777 has three Primary Flight Computers (PFC) that are responsible for flight control laws computation and four Actuator Control Units (ACE) that are responsible for the closed-loop control of their responsible flight control surfaces. The ACE is primarily an analog ...

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