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6

The tailplane should produce less lift than the main wing, for pitch stability. That is to say, its lift is negative relative to the wing lift. Its lift need not be wholly negative (pointing down), although it usually is during takeoff and landing. But yes, as a first approximation, the direction of camber matches the direction of lift. Also yes, negative ...


5

Indeed, the airfoils on many horizontal tail surfaces do have negative camber. This is mostly in combination with powerful flaps on the wing so the tailplane will continue to work with flaps extended, when it needs to develop a relatively high downforce (which is indeed the same as negative lift). The extended wing flaps result in higher wing downwash so the ...


5

Most tailplanes (except for specialist applications, like endurance designs in model airplanes) have a symmetrical airfoil, whether thickened or effectively a flat plate. Camber of any sort is unusual in tailplanes for full size aircraft -- except as it might be incidentally produced by elevator trim, and in that case, it might be either upward or downward, ...


5

The pictures in the question show the normal position of the MiG-29 ailerons. That's how they are unless a roll is commanded. According to Mikoyan Mig-29 Fulcrum Pilot's Flight Operating Manual (google books) the slight upward position is set to improve yaw stability during roll meneuvers: As for whether this angle (neutral position of ailerons) changes in ...


4

You'll only get opinions here, but from 40 years in the business, my opinion is not much. Airplanes are a balance of compromises and after much trial and error, dead ends, and false starts, a combination hits a sweet spot in the balancing act and that becomes a near universal configuration. When someone deviates, it MAY create a new configuration paradigm, ...


3

Lift force over the wing is said to be of elliptical distribution if the lift per span ($L'$) along the wing span is of the following: $$L'(y) = \rho_\infty V_\infty \Gamma_0 \sqrt{1-(\frac{2y}{b})^2}$$ where $\rho_\infty$ is density of the airflow, $V_\infty$ is the free-stream airspeed, $b$ is length of wing span, $y$ is lateral coordinate along the wing ...


3

I am working on a project where I have to design a plane which has to cruise at 0.85 Mach at 35,000 ft. While working on the wing design, I quickly discovered that 6 series airfoils, with a good amount of thickness ratio, have a low Critical Mach Number. So, I started exploring Supercritical Airfoils (SC Airfoils). For doing analysis of SC airfoils ...


3

Reference area for the aerodynamic coefficients (lift, drag, moment) is the planform area. Your picture shows only one wing, while the reference area S would also take into account the fuselage and the other wing: orange times twice blue and then some. In its most generic case, the equation for wing area S is $$\int_{-b/2}^{b/2} c \cdot dy$$ with b = wing ...


2

The cost of approving an STC for an aircraft can be quite expensive and the return on investment may not have been worth it. ------------------------------------------ |Aircraft | # Built | Year Certified | ------------------------------------------ |Learjet 23 | 104 | 1964 | |Learjet 24 | 259 | 1966 to 1976 | (All variants) |...


2

I implemented a program using Matlab for S.C calculus purposes (I'm actually involved in an aircraft project and, fortunately (or not), I'm the structures guy. I have based the code and the theory in a PDF bibliography that is linked w/ the .zip folder. You'll notice two matlab codes: -One is named "Load_Airfoil_Coordinates_using_MATLAB.m". It loads any ....


1

… elliptical lift distribution gives the least amount of induced drag. Not quite. The elliptical lift distribution (read JZYL's answer for an explanation what it is) will only give the least amount of induced drag for a given span. That means that wings with more span and a more triangular lift distribution will be lighter, thus needing less lift and, ...


1

A few constructions, such as the Zenith CH 701 STOL, have horizontal stabs with non-symmetric, inverted airfoils:


1

Three definitions first (simply): CoW (Centre of Weight) and CoP (Centre of Pressure). These two govern the aircraft (any) while flying (lets forget about thrust and drag now - the other two). AoA (Angle of Attack) is the anlge between the leading edge and the relative airflow. In case of airplanes CoW and CoP are close together. For a Paraglider, CoW is ...


1

Thinking of lift and drag as “causing” each other is—by definition—technically flawed. Lift and drag are the “final” “result” of the magnitude of various pressure forces acting on the airfoil in various directions, resolved into two directions: parallel to the direction of airfoil travel and perpendicular to the direction of airfoil travel. The former is ...


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