P Post-test 3 (Aircraft Structures and Design)

1. What role does the Ground Control Station (GCS) play in UAV communication systems?

A. It facilitates two-way communication with the UAV

B. It controls the payload deployment mechanism

C. It serves as a navigation beacon for the UAV

D. It provides real-time video streaming

A. It facilitates two-way communication with the UAV

2. Which of the following is a potential load case that an aircraft structural member may be subjected to?

A. Passenger seating loads

B. Solar radiation loads

C. Lightning strike loads

D. Emergency braking loads

A. Passenger seating loads

3. In the 'Quad-rotor' VTOL configuration, how are thrust changes achieved for each rotor?

A. By altering the shape of the rotor blades

B. By adjusting the number of rotor blades

C. By changing the speed of rotation

D. By changing the pitch of the rotor blades

C. By changing the speed of rotation

4. A particle of mass 1 kg is moving in a circle with a radius of 2 m. If the particle's angular velocity is 2 rad/s, what is its kinetic energy?

A. 8J

B. 6J

C. 4J

D. 2J

C. 4J

5. To achieve the maximum turn rate and minimum turn radius during air combat maneuvering, an aircraft design should aim for which operational condition?

A. High cruise altitude with minimum wing loading

B. Maximum possible speed at the maximum structural load factor limit

C. Low angle of attack at maximum engine thrust limit

D. Minimum maneuver speed at the maximum usable lift coefficient

D. Minimum maneuver speed at the maximum usable lift coefficient

6. The angle of twist of a circular cross-section.

A. The ratio of the product of torque to the product of polar moment of inertia, shear modulus of elasticity and length.

B. The sum of the product of torque and length to the product of polar moment of inertia and shear modulus of elasticity.

C. The ratio of the product of torque and length to the product of polar moment of inertia and shear modulus of elasticity.

D. The product of the product of torque and length to the product of polar moment of inertia and shear modulus of elasticity.

C. The ratio of the product of torque and length to the product of polar moment of inertia and shear modulus of elasticity.

7. Typically, airliners have _____, _____ wings.

A. high; sweptback

B. low; sweptback

C. mid-; delta

D. low; tapered

B. low; sweptback

8. To apply the area rule to a transonic aircraft at the wing fuselage junction, how must the fuselage geometry be modified?

A. The fuselage must be indented at the wing region

B. The fuselage must be shortened in length

C. The fuselage cross sectional area must be expanded at the wing root

D. Vertical tail area must be reduced to balance the wing volume

A. The fuselage must be indented at the wing region

9. Which loading condition occurs when the aircraft wing upper surface experiences lift forces?

A. Compression

B. Torsion

C. Shear

D. Tension

A. Compression

10. For columns having different types of supports, column length L represents the distance between the points of zero moment on the column will be modified to.

A. Effective length

B. Ideal length

C. Full length

D. Half length

A. Effective length

11. What is the effect of a small wing incidence on cruise drag?

A. ZERO

B. LOW

C. HIGH

D. REMAIN AS IS

B. LOW

12. Empty weight that consists of the airframe, engine, unusable fuel and oil, as well as standard and optional equipment specified in the equipment list is called:

A. standard empty weight

B. licensed empty weight

C. zero fuel weight

D. basic empty weight

A. standard empty weight

13. How does the CG envelope affect an aircraft's payload?

A. It has no effect on payload.

B. It determines the amount of fuel to be burned.

C. It determines the maximum payload that can be carried.

D. It determines the number of flight crew on board.

C. It determines the maximum payload that can be carried.

14. What happens to the static longitudinal stability of an aircraft if its CG moves aft of its neutral point?

A. The aircraft becomes statically unstable in pitch

B. The roll damping derivative increases substantially

C. The aircraft stall speed automatically drops to zero

D. The aircraft becomes excessively pitch-stable and impossible to pitch up

A. The aircraft becomes statically unstable in pitch

15. Which is not an effect of a dorsal fin?

A. reduces the fin's effective aspect ratio

B. increases the directional stability of the fuselage at large sideslip angles

C. improves lateral stability at large sideslip angles

D. increases the fin's stalling angle

C. improves lateral stability at large sideslip angles

16. Which type of stress occurs when forces are applied in opposite directions, causing the material to stretch or elongate?

A. tensile stress

B. torsional stress

C. bending stress

D. shear stress

A. tensile stress

17. A cylindrical fuselage structure with radius of 1.2 m and skin thickness of 1.5 mm is subjected to internal cabin pressure of 55 kPa. What is the internal hoop stress developed in the skin shell?

A. 66 MPa

B. 44 MPa

C. 88 MPa

D. 22 MPa

B. 44 MPa

18. A ball is thrown straight up into the air with an initial velocity of 20 m/s. What is its velocity after 3 seconds?

A. 5 m/s

B. 10 m/s

C. 15 m/s

D. 20 m/s

A. 5 m/s

19. How do control surface loads affect the maneuverability of an aircraft?

A. They have no effect on maneuverability

B. They increase stability

C. They decrease the aircraft's control

D. They enhance roll control

D. They enhance roll control

20. What is the main objective of UCAV (Unmanned Combat Air Vehicle) in advanced strike missions?

A. Achieving high-speed flight

B. Maintaining stealth

C. Maximizing payload capacity

D. Conducting long-endurance missions

B. Maintaining stealth

21. A system of two particles is rotating about an axis with a constant angular velocity. If the distance between the particles is increased, what happens to the angular velocity of the system?

A. The angular momentum of the system increases.

B. The angular velocity remains constant.

C. The angular velocity increases.

D. The angular velocity decreases.

B. The angular velocity remains constant.

22. Which is true for adverse yaw?

A. Down-going aileron decreases the camber of the outer wing, while the up-going aileron increases the camber of the inner wing.

B. Increased lift created by the up-going aileron increases the induced drag for that wing, while the induced drag for the down-going aileron decreases

C. Increased lift created by the down-going aileron increases the induced drag for that wing, while the induced drag for the up-going aileron decreases

D. Up-going aileron increases the camber of the outer wing, while the down-going aileron decreases the camber of the inner wing

C. Increased lift created by the down-going aileron increases the induced drag for that wing, while the induced drag for the up-going aileron decreases

23. Which loading condition occurs when the aircraft experiences twisting forces?

A. Torsion

B. Shear

C. Compression

D. Tension

A. Torsion

24. Which structural configuration places the engines on pylons mounted above the wings?

A. Low-wing configuration

B. High-wing configuration

C. Wingtip configuration

D. Mid-wing configuration

B. High-wing configuration

25. A sled weighing 100 N rests on a plane inclined at an angle of 30 degrees to the horizontal for which the coefficient of static friction is 0.40 and the coefficient of kinetic friction is 0.20. What minimum force parallel to the plane must be applied to keep this sled moving up this plane?

A. 30 N

B. 15 N

C. 20 N

D. 25 N

D. 25 N

26. This is the maximum load anticipated on its lifetime of service.

A. limit load

B. ultimate load

C. peak load

D. load factor

A. limit load

27. The line in a beam or other member is subjected to a bending action in which the fibers are neither stretched nor compressed or where the longitudinal stress is zero.

A. Vertical Axis

B. Outer surfaces

C. Neutral Axis

D. Longitudinal Axis

C. Neutral Axis

28. Which wing vertical position offers superior aerobatic maneuverability?

A. HIGH WING

B. LOW WING

C. BIPLANE

D. MID WING

D. MID WING

29. An aircraft designer relocates twin turbofan engines from under the wings to the aft fuselage. How does this structural change typically impact the horizontal tail sizing calculation?

A. Allows a smaller horizontal tail area due to an increased tail moment arm

B. Has no effect on horizontal tail sizing since volume ratio is independent of CG location

C. Eliminates the requirement for a horizontal tail by shifting pitching moment stability entirely to the wing

D. Requires a larger horizontal tail area due to a reduced moment arm to the aft CG position

D. Requires a larger horizontal tail area due to a reduced moment arm to the aft CG position

30. During inspection of the flight control system of an airplane equipped with differential-type aileron control, side-to-side movement of the control stick will cause

A. The left aileron to move through a greater number of degrees from full up to full down than the right aileron

B. Each aileron to have a greater down travel from the streamlined position than up travel

C. Each aileron to have a greater up travel from the streamlined position than down travel

D. The right aileron to move through a greater number of degrees from full down to full up than the left aileron

C. Each aileron to have a greater up travel from the streamlined position than down travel

31. This is the quality of an aircraft to correct for conditions that may disturb its equilibrium, and return to or continue on the original flightpath.

A. stability

B. center of pressure

C. center of gravity

D. aerodynamics

A. stability

32. During which stage of the overall aircraft design process are major configuration trade studies performed, preliminary sizing refined, and baseline geometric freeze achieved before entering detail design?

A. Detail design phase

B. Conceptual design phase

C. Preliminary design phase

D. Fabrication and assembly phase

C. Preliminary design phase

33. This is degradation of a material due to chemical and/or electrochemical reactions with the environment.

A. corrosion

B. wear and tear

C. deformation

D. deterioration

A. corrosion

34. A uniform rod of mass 10 kg and length 1 m is rotating about an axis passing through one end and perpendicular to its length. What is the moment of inertia of the rod about this axis?

A. 0.5 kg m^2

B. 2 kg m^2

C. 1 kg m^2

D. 0.1 kg m^2

B. 2 kg m^2

35. During high speed low altitude flight, which two physical mechanisms generate the dominant noise signatures of a jet powered aircraft?

A. Cockpit heating systems and fuel sloshing in tanks

B. APU combustion and interior cabin pressurization relief valves

C. Jet exhaust shear mixing and airframe turbulence

D. Fuselage skin vibration and tire rolling friction

C. Jet exhaust shear mixing and airframe turbulence

36. Materials that exhibit little or no yielding before failure are referred to as

A. Elastic material

B. Brittle material

C. Stiff material

D. Ductile material

B. Brittle material

37. Which type of UAV operates within a range of 100 to 300 kilometers?

A. Close-Range UAV

B. MALE- Medium altitude long endurance

C. TUAV- Medium Range or Tactical UAV

D. HALE- High altitude long endurance

C. TUAV- Medium Range or Tactical UAV

38. Which structural configuration places the engines on pylons mounted below the wings?

A. High-wing configuration

B. Wingtip configuration

C. Low-wing configuration

D. Mid-wing configuration

C. Low-wing configuration

39. Why are structural composite sandwich panels with lightweight honeycomb cores frequently used for aircraft interior floor panels and bulkheads?

A. They can be easily reshaped on site using hand tools without damaging structural integrity

B. They provide a high bending stiffness to weight ratio

C. They provide high electrical conductivity for grounding lightning strikes

D. They withstand direct exposure to hot jet engine turbine exhaust gas

B. They provide a high bending stiffness to weight ratio

40. Which type of structure allows the pilot to control the aircraft's roll?

A. Spoiler

B. Elevator

C. Flap

D. Aileron

D. Aileron

41. How does tail rotor sizing and thrust requirement change during high-altitude hover in warm atmospheric conditions?

A. Increased speed of sound reduces advancing blade tip Mach numbers, lowering anti-torque requirements

B. Reduced dynamic pressure eliminates main rotor torque, decreasing tail rotor thrust demand

C. Decreased air density requires higher pitch angles and thrust, increasing tail rotor power

D. Higher kinematic viscosity stabilizes tail rotor tip vortices, reducing required blade area

C. Decreased air density requires higher pitch angles and thrust, increasing tail rotor power

42. Which of the following does not describe a fixed slot?

A. It delays airflow separation at higher angles of attack.

B. It allows a higher maximum center of lift.

C. It directs airflow to the upper wing surface.

D. It increases the wing camber.

D. It increases the wing camber.

43. An aircraft with a maximum landing weight of 120,000 N requires a maximum approach lift coefficient of 2.4. If the maximum acceptable landing stall speed at sea level is 50 m/s, what is the maximum allowable wing loading?

A. 3000 Pa

B. 1470 Pa

C. 3675 Pa

D. 7350 Pa

C. 3675 Pa

44. High thickness ratio for subsonic aircraft means

A. high wing drag, good maximum lift

B. high wing drag, poor maximum lift

C. low wing drag, good maximum lift

D. low wing drag, poor maximum lift

A. high wing drag, good maximum lift

45. A bullet of mass 0.01 kg is fired from a gun with a muzzle velocity of 300 m/s. What is the recoil velocity of the gun?

A. -3 m/s

B. -0.3 m/s

C. -30 m/s

D. -0.01 m/s

A. -3 m/s

46. Why is the 'Single-main-rotor' VTOL configuration considered asymmetric in all planes?

A. The tail rotor is smaller than the main rotor

B. The torque of the main rotor creates an imbalance

C. It lacks a horizontal stabilizer

D. Due to the shape of the rotor blades

B. The torque of the main rotor creates an imbalance

47. Spoilers are unique in that they may also be fully deployed on both wings to act as

A. Thrust Reverser

B. Thrust Device

C. Ailerons

D. Speed Brakes

D. Speed Brakes

48. To maximize for range, the aircraft should perform

A. Climbing to higher altitude

B. Slow down

C. Both A and B

D. Either A and B

C. Both A and B

49. This is a small, secondary flight control surface attached to the trailing edge of a larger, primary control surface.

A. trim tab

B. flap

C. slat

D. stabilizer

A. trim tab

50. Two objects of the same weight are placed at -50 and +20 from the datum. Where should another load of the same weight be placed?

A. 30 inches aft of the first load

B. 30 inches forward of the datum

C. 30 inches aft of the second load

D. 30 inches aft of the datum

D. 30 inches aft of the datum