# Tag Info

4

Structural Factor of Safety is the margin between the normal limit load and the ultimate load the structure has to take. It is normally 1.5 times the yield load or limit load of the structure. The structure is designed to withstand the Limit Load that is applicable to the category, in the case of Transport airplanes 2.5G, without permanent deformation. The ...

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Back in the pioneer days both types competed fiercely. The braced monoplane has similar structural depth to the braced biplane but less than twice the total wing area, so many argued in its favour. On the other hand, the shallower angle of its bracing wires introduced greater compressive forces in the wing spars, so they had to be strengthened and that added ...

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"A braced monoplane has most of the structural advantages of a monoplane with less of the aerodynamic disadvantages" Very surprising statement since, in the previous paragraph it is said: "the extra wing produces 20% more lift with 100% parasitic drag increase". Actually, with spars, cantilever wing structure, and the aerodynamic ...

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How they were invented As @Bianfable wrote: They were first used on the Douglas DC-9. On the Douglas quad-jet DC-8, leading-edge slots are used, compared to the Krueger flaps used by Boeing for its 707:[1] A DC-8 door-operated slot next to an engine pylon (diecastaircraftforum.com) When Douglas put those slots on the DC-9 (tail-mounted engines) during ...

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First, analyzing the data shows some lift and drag benefits at low AOA but much worse performance at higher AOA. Why? Because with undercambered wings, at higher AOA the concave bottom creates a higher pressure lifting "bubble" which a "permeable" area hurts. At lower AOA, a little "bleed" through the wing may enhance lift and ...

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In some aircraft, such as the Canadair CP-107 Argus, the control yoke is not actually connected to the ailerons. Rather, they are connected to servo tabs, which are basically small ailerons attached to the rear of the actual ailerons (not to be confused with trim tabs, which look exactly the same but are controlled differently). Turning the yoke left causes ...

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Most likely the adverse yaw effect (due to the induced drag of the increased lift on the down-aileron side) is causing the wing to yaw the opposite direction from the intended roll, and the yaw causes the dihedral induced roll (proverse to the yaw) to override the aileron input. This situation is very commonly seen with very slow flying model aircraft -- ...

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For the mean geometric chord, calculate wing area divided by span. For the mean aerodynamic chord you integrate chord squared over span and divide the result by wing area. $$l_\mu = \frac{\int^{+\frac{b}{2}}_{-\frac{b}{2}}l^2dy}{S}$$

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Silly comments aside, "fat" wings, ones with greater camber, were all the rage 100 years ago when designers found they could eliminate draggy external bracing by building cantilever wings. Hugo Junkers was one of these pioneers. Wind tunnel testing also showed increased camber not only increased lifting efficiency, but also, combined with large, ...

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Also, you have to think that the air does not hit the wing at a 90* angle to the leading edge on a swept wing. The shape of the wing ribs is not necessarily the shape that the air is being in contact with. It is probably going to be a longer trip than the shape of the rib in certain areas of the wing, like close to the tip, where both leading and trailing ...

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Yes, sweep makes a wing heavier and less efficient. But making the airfoil of a straight wing thinner runs into diminishing returns and also will drive up mass. Since a thin wing needs to create the same lift as a thicker one, only the local speed increase from thickness can be tackled by making the airfoil thinner. The speed increase necessary for lift ...

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The downwash is about as high as wide, and angled only by a few degrees (more at slow speed). So the longitudinal distance needs to be many times longer than the wing span to make the wings independent. And it would still be less efficient than increasing the span: If you double the span, you will decrease induced drag four times. If you half the lift, you ...

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Since both the lift curve slope and the effective angle of attack are reduced by the cosine of the sweep angle at quarter chord, the lift coefficient of a swept wing at the same geometric angle of attack is reduced by the square of the cosine of the sweep angle. Also, the pressure distribution over chord differs between straight and swept wings, especially ...

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Because wetted aspect ratio $b^2/{S_w}$ merely improves on wing aspect ratio as an estimate of efficiency, for $b$ just choose whichever wingspan is largest. That's good enough to compare one tandem planform to another. You could get fancy and use a weighted average of the wings' spans, weighted by how much lift each one produces, with those in turn ...

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