# Aircraft Maintenance Questions and Answers – Flight Dynamics

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This set of Aircraft Maintenance Multiple Choice Questions & Answers (MCQs) focuses on “Flight dynamics”.

1. The three critical flight dynamics parameters are?
a) Roll, pitch and yaw
b) Roll, pitch and jaw
c) Roll, play and yaw
d) Roll, play and jaw

Explanation: The three critical flight dynamics parameters are roll, pitch and yaw. They may also be referred to as the angles of rotation w.r.t. the aircraft’s three principal axes about its center of gravity.

2. What happens if an aircraft yaws about its center of gravity?
a) A sideslip angle arises
b) Aircraft will crash
c) Aircraft will start descending
d) Angle of attack increases

Explanation: When an aircraft yaws about its center of gravity, it creates a sideslip angle. It is the angle between the wheels of an aircraft and the direction in which the aircraft is travelling.

3. Which of the following gives the viscosity of flow?
a) Mach Number
b) Knudsen Number
c) Specific heat ratio
d) Reynolds Number

Explanation: Viscosity of the flow is given by Reynolds Number. It is represented by Re. Mach number indicates the compressibility of flow and Knudsen number indicates rarefaction of the flow.

4. Which of the following is not an aerodynamic coefficient?
a) Pressure coefficient
b) Absolute temperature
c) Lift coefficient
d) Drag coefficient

Explanation: Absolute temperature is not an aerodynamic coefficient. However, pressure coefficient, lift coefficient and drag coefficient are all aerodynamic coefficients. A few other aerodynamic coefficients are lateral force coefficient and friction coefficient.

5. Which of the following is not true about yaw?
a) About the vertical body axis
b) Positive with the nose to starboard
c) Measured in Hertz
d) Type of rotation

Explanation: Yaw rotation is the rotation of a body, which changes the direction in which it is pointing. It is an essential flight dynamic and is usually measured in degrees per second or radians per second.

6. Flight dynamics studies the efficiency of vehicles travelling through air.
a) True
b) False

Explanation: Flight dynamics studies the stability and control of vehicles travelling through air. It does not study the efficiency of these vehicles; however, flight dynamics parameters are designed so as to improve the efficiency of these vehicles.

7. The equilibrium roll angle is known as __________
a) Roll angle
b) Angle of incidence
c) Zero bank angle
d) Angle of attack

Explanation: The equilibrium roll angle is known as zero bank angle; it may also be called wings level. The three critical flight dynamics refer to rotations about the respective axes starting from a defined equilibrium state.

8. Which is the most dominant force in spacecraft flight dynamics?
a) Gravitational force
b) Nuclear force
c) Air resistance force
d) Lift and drag

Explanation: The most dominant force in spacecraft flight dynamics, is the gravitational force. This is because aerodynamic forces affecting the spacecraft in air, are very small, thereby making gravitational force dominant.

9. Control systems adjust the orientation of a vehicle about its __________
a) Pitch
b) Wheels
c) Centre of mass
d) Centre of gravity

Explanation: The control systems adjust the orientation of a vehicle about its centre of gravity. The control systems help rotate the aircraft in pitch, roll and yaw. It may be used to pitch the aircraft up or down.

10. An aircraft adjusts the lift generated by the wings when it pitches nose up or down by adjusting the angle of attack.
a) True
b) False

Explanation: Aircrafts increase or decrease the lift generated by the wings, by increasing or decreasing the angle of attack. Angle of attack is adjusted by changing the position of the nose of an aircraft.

11. Spacecraft flight dynamics does not involve which of the following forces?
a) Propulsive force
b) Gravitational force
c) Electromagnetic force
d) Lift and drag

Explanation: Spacecraft flight dynamics does not include electromagnetic force. However, propulsive force, lift and drag and gravitational force are all part of spacecraft flight dynamics. Propulsive forces are most dominant in rockets.

12. What are the major sources of change in the aerodynamic forces and moments applied to an aircraft?
a) Angle of attack of the wing and the angle of attack
b) Angle of attack of the wing and the angle of attack of the vertical tail
c) Angle of attack of the wing and the angle of incidence
d) Angle of incidence and the angle of attack of the vertical tail

Explanation: The two major sources of change in the aerodynamic forces and moments applied to an aircraft are the angle of attack of the wing and the angle of attack of the vertical tail. The two angles are important to maintain the center of gravity of an aircraft.

13. Aircrafts are streamlined from nose to tail to reduce __________
a) Turbulence
b) Thrust
c) Gravitational force
d) Drag

Explanation: The aircrafts are streamlined from nose to tail to reduce drag on the aircraft. Increased drag reduces the airspeed of an aircraft and hence increases flying time.

14. Angle of attack of the vertical tail is also known as __________
a) Sideslip angle
b) Critical angle
c) Zero bank angle
d) Angle of incidence

Explanation: The angle of attack of the vertical tail is also known as Sideslip angle. It may also be referred to as beta. Similarly, the angle of attack of the wing is referred to as alpha.

15. Which of the following aircraft systems includes an actuator?
a) Hydraulic systems
b) Electronic systems
c) Communication systems
d) Control systems 