Static Stability & Control

Subtopic: Control Surfaces (Elevator, Aileron, Rudder)

A general aviation airplane is in steady and level flight. The airplane is prone to adverse yaw. Which one of the following options best describes the deflections of aileron and rudder to achieve a coordinated right turn?

Subtopic: Longitudinal Static Stability & Neutral Point

To achieve longitudinal static stability of a general aviation airplane, which one of the following conditions should be satisfied?

Subtopic: Control Surfaces (Elevator, Aileron, Rudder)

In a conventional configuration airplane, the rudder can be used:

Subtopic: Control Surfaces (Elevator, Aileron, Rudder)

For an airplane having directional / weathercock static stability, which of the following options is/are correct?

Subtopic: Longitudinal Static Stability & Neutral Point

For a longitudinally statically stable aircraft, which one of the following represents the relationship between the coefficient of pitching moment about the center of gravity mcgC and absolute angle of attack a ? (Note: nose-up moment is positive.)

Subtopic: Longitudinal Static Stability & Neutral Point

For a conventional statically stable airplane, which one of the following combinations of pitching moment parameters about the center of gravity is CORRECT?

Subtopic: Static Margin & Stick-Fixed/Free Stability

An aerospace system operating under standard sea level conditions is governed by Static Stability & Control (Static Margin & Stick-Fixed/Free Stability). Compute the required parameter in standard SI units (rounded off to the acceptable range).

Subtopic: Control Surfaces (Elevator, Aileron, Rudder)

Which of the following statements about adverse yaw of an airplane is/are correct? P. It is caused by flow separation resulting from large rudder deflection. Q. It is caused by dissimilar drag forces acting on the two halves of the wing resulting from aileron deflections of same magnitude. R. It can be eliminated by ensuring that the upward deflection of one aileron is greater than the downward deflection of the opposite aileron.

Subtopic: Longitudinal Static Stability & Neutral Point

200 N P MUNT 100 Nm 0.5m 100 Nm 0.5m MARR

Subtopic: Control Surfaces (Elevator, Aileron, Rudder)

The design of an airplane is modified to increase the vertical tail area by 20% and decrease the moment arm of the vertical tail by 20%. The ratio of the new directional stability derivative $C_{n\beta}$ (due to the vertical tail) to the original value is _________ (round off to 2 decimal places).

Subtopic: Control Surfaces (Elevator, Aileron, Rudder)

The natural frequency (in rad/s) of the spring-mass system shown in the figure below is _____ (accurate to one decimal place).

Subtopic: Longitudinal Static Stability & Neutral Point

A statically-stable aircraft has a CL$\alpha$= 5 (where the angle of attack, $\alpha$, is measured in radians). The coefficient of moment of the aircraft about the center of gravity is given as CM,c.g = 0.05 - 4$\alpha$. The mean aerodynamic chord of the aircraft wing is 1 m. The location (positive towards the nose ) of the neutral point of the aircraft from the center of gravity is ______ (in m, accurate to two decimal places).

Subtopic: Control Surfaces (Elevator, Aileron, Rudder)

A pilot was flying a single engine propeller aircraft and maintaining a steady level flight at a lift coefficient, Cr=0.5 at an altitude of 500 m. Due to some emergency, at the same altitude (500 m), the pilot had to fully deploy the landing gear. If the pilot wants to maintain steady level flight at the same C1=0.5 and at the same altitude, which of the following control actions should the pilot undertake:

Subtopic: Control Surfaces (Elevator, Aileron, Rudder)

A pilot was flying a single engine propeller aircraft and maintained steady level flight at trim. Due to torque reaction and slipstream rotation from a clockwise rotating propeller (viewed from the cockpit), the airplane tends to naturally:

Subtopic: Control Surfaces (Elevator, Aileron, Rudder)

Indicated airspeed is used by a pilot during

Subtopic: Control Surfaces (Elevator, Aileron, Rudder)

An aircraft is flying level in the North direction at a velocity of 55 m/s under cross wind from East to West of 5 m/s. For the given aircraft C n$\beta$ = 0.012/deg and C n$\delta$r = - 0.0072/deg, where $\delta$r is the rudder deflection and $\beta$ is the side slip angle . The rudder deflection exerted by pilot is __________ degrees.

Subtopic: Control Surfaces (Elevator, Aileron, Rudder)

Determine the correctness or otherwise of the following assertion [a] and reason [r]: Assertion [a]: Aircraft directional static stability can be improved by moving the vertical tail rearward. Reason [r]: Moving the vertical tail rearward increases the moment arm from the tail aerodynamic center to the aircraft center of gravity.

Subtopic: Static Margin & Stick-Fixed/Free Stability

Consider the following four statements regarding aircraft longitudinal stability: P. CM,cg at zero lift must be positive Q. $\partial$CM,cg/$\partial \alpha$a must be negative ($\alpha$a is absolute angle of attack) R. CM,cg at zero lift must be negative S. Slope of CL versus $\alpha$a must be negative Which of the following combination is the necessary criterion for stick fixed longitudinal balance and static stability?

Subtopic: Static Margin & Stick-Fixed/Free Stability

Minimum and maximum speeds of the airplane in level flight condition at sea-level in m/s are respectively

Subtopic: Control Surfaces (Elevator, Aileron, Rudder)

The airplane trim lift coefficient L trimC is

Subtopic: Control Surfaces (Elevator, Aileron, Rudder)

In an aircraft, the dive manoeuvre can be initiated by:

Subtopic: Control Surfaces (Elevator, Aileron, Rudder)

In an aircraft, elevator control effectiveness determines

Subtopic: Control Surfaces (Elevator, Aileron, Rudder)

An aircraft is trimmed straight and level at true air speed (TAS) of 100 m/s at standard sea level (SSL). Further, pull of 5 N holds the speed at 90 m/s without re-trimming at SSL (air density = 1.22 kg/m^3). To fly at 3000 m altitude (air density = 0.91 kg/m^3) and 120 m/s TAS without re-trimming, the aircraft needs

Subtopic: Static Margin & Stick-Fixed/Free Stability

The angle of incidence of tail to trim the wing-tail combination for a 5% static margin is

Subtopic: Control Surfaces (Elevator, Aileron, Rudder)

Thermodynamic cycle on which the jet engine operates can be Q.24

Subtopic: Longitudinal Static Stability & Neutral Point

The damping ratio 5 is approximately:

Subtopic: Control Surfaces (Elevator, Aileron, Rudder)

The trim curves of an aircraft are of the form Cm.. = (0.05-0.26,) - 0.16, where the elevator deflection angle, o,, is in radians. The static inargin of the aircraft is:

Subtopic: Control Surfaces (Elevator, Aileron, Rudder)

2010 AE 0.44 The trim curves of an aircraft are of the form C... = (0.05 - 0.28,) - 0.1C, where ine elevaror deflection angle, ó,, is in radians. The change in elevator deflection needed to increase the lift coefficient from 0.4 10 0.9 is :

Subtopic: Static Margin & Stick-Fixed/Free Stability

Core digits 2, 2. 3. 3. 3. 4. 4. 4. 4 how many distinct digit numbers greater than 3000 can be

Subtopic: Longitudinal Static Stability & Neutral Point

Suppose the non-constant functions F(x) and G(t) satisfy d^2 F/dx^2 + p^2 F = 0 and dG/dt + c^2 p^2 G = 0, where p and c are constants. Then the function u(x,t) = F(x)G(t) definitely satisfies:

Subtopic: Control Surfaces (Elevator, Aileron, Rudder)

The figure below shows the variation of Cm versus a for an aircraft for three combinations of elevator deflections and locations of centre of gravity. In the figure, lines P and Q are parallel, while lines Q and R have the same intercept on the Cm axis. P Q R Which of the following statements is true?

Subtopic: Static Margin & Stick-Fixed/Free Stability

Which of the following statements about the static stick-fixed stability of this aircraft is true?

Subtopic: Control Surfaces (Elevator, Aileron, Rudder)

If the center of gravity of an airplane is moved forward towards the nose of the airplane; the ma. (maximum value of the lift coefficient) value for which the airplane can be trimmed (C, = 0) will

Subtopic: Control Surfaces (Elevator, Aileron, Rudder)

rudder deflection If the contribution of only the horizontal tail of an airplane was considered for estimating да , and if the tail moment arm 4, was doubled, then how many times the original value would the new * become ? да

Subtopic: Control Surfaces (Elevator, Aileron, Rudder)

If horizontal tail area is increased while the elevator to horizontal tail area ratio is kept same, then

Subtopic: Control Surfaces (Elevator, Aileron, Rudder)

The most aft location of the airplane center of gravity permitted to fulfill designer's requirement on longitudinal static stability is