Questions and Answers - Aircraft Structures | Aircraft Systems

Questions and Answers - Aircraft Structures

Study Aid Questions

Fill in the Blanks

1. The part of the aircraft that is designed to carry a load or resist stress is the _________.

2. All aircraft are subjected to five major stresses: tension, compression, bending, ________, and __________.

3. Tensile strength is measured in __________ which is written as __________.

4. Wings that require no external bracing are known as ___________ design.

5. __________ internal structures are made up of spars and stringers.

6. Spars are to wings as ___________ are to the fuselage.

7. I‐beam spars are made up of two components: the _________ which is the vertical section and the __________ which is the horizontal section.

8. A stainless steel or titanium bulkhead known as a ________ is used to isolate the ________ from the rest of the aircraft.

9. Cowl flaps are moveable parts of the cowling that open and close to ________.

10. The primary flight controls include the ailerons, elevators, and rudders which control the stability around the ________, ________, and ________ axes respectively.

11. Primary flight control surfaces need to be balanced so they do not vibrate or ________.

12. When the aircraft is turned to the left, the aileron on the pilot’s ________ points up.

13. Elevators move the aircraft around the _________ axis.

14. When the right pedal is pushed forward, it deflects the rudder to the ________ which moves the nose of the aircraft to the right.

15. Flaps that slide aft to increase the total area of the wing are known as ________ flaps.

16. Slats increase the ________ at which laminar airflow can exist.

17. Heavy or high performance aircraft have ________ on the top of their wings that disrupt airflow when deployed.

18. The ________ is the location from which all other stations are located.

19. Firewalls are typically made from _________.

20. Teetering hinges in a semi‐rigid system allow for movement of the flap _________ while preventing movement ________.


1. Wing braces are the main structural member of a wing. TRUE/FALSE

2. Torsion resists pulling forces. TRUE/FALSE

3. Tensile strength is generally greater than or equal to shearing strength. TRUE/FALSE

4. Longerons are the longitudinal members in a semimonocoque fuselage. TRUE/FALSE

5. The benefit of a semimonocoque fuselage compared to a monocoque fuselage is that the semimonocoque fuselage does not require the skin to carry any load thereby reducing the stress on the skin. TRUE/FALSE

6. Box beam wing constructions are used on transport category aircraft. TRUE/FALSE

7. False ribs are those ribs which are used strictly for shaping the camber of the wing and do not provide any load support. TRUE/FALSE

8. Cowlings are detachable panels which provide smooth airflow over the engine and protect it from damage. TRUE/FALSE

9. Ribs can be lightened by stamping holes in the assembly. TRUE/FALSE

10. High performance aircraft typically have fly‐by‐wire systems that utilize electrical power to move the elevators. TRUE/FALSE

11. Fuel‐carrying bladders located in a wing are known as wet wing designs. TRUE/FALSE

12. Worm drives and flap tracks are used to move fowler flaps along their designed route of travel. TRUE/FALSE

13. Leading edge flaps are independent of the trailing edge flaps. TRUE/FALSE

14. Vortex generators are designed to reduce drag created by wingtip vortices. TRUE/FALSE

15. Conventional gear and tricycle gear are interchangeable terms. TRUE/FALSE

16. Aircraft equipped with pontoons or floats are sometimes known as amphibious aircraft. TRUE/FALSE

17. Water line measurements are perpendicular to the horizon. TRUE/FALSE

18. Helicopters are moved horizontally by changing the angle of attack on the rotor blades. TRUE/FALSE

19. Dissymmetry of lift causes blades to flutter. TRUE/FALSE

20. Torque produced by the main rotors tries to spin the fuselage in the direction of blade rotation. TRUE/FALSE

Knowledge Application Questions

1. Why are the rotors of a helicopter considered part of the airframe?

2. Define strain.

3. Describe stresses involved on a part being bent or subject to bending stress.

4. Cowlings and fairings do not require a high degree of strength but what characteristic is important for parts such as these?

5. What are the structural members that make up a truss‐framed fuselage and what is it typically covered with?

6. What is the biggest problem associated with the monocoque type fuselage?

7. How is the monocoque type fuselage different than the semi‐monocoque type?

8. What causes metal fatigue in a pressurized aircraft fuselage structure?

9. When is the use of landing gear jury struts necessary and what purpose do they serve?

10. What is the function of the wing spar?

11. Where are false ribs located and what is their function?

12. Describe the characteristics of a nacelle and its components.

13. Directional control of a fixed‐wing aircraft takes place around which axes? What are the respective control surfaces that move about these axes?

14. What affect does moving the aileron down have on the wing?

15. What are the functions of slots and where are they located?

16. How are balance tabs moved and what is their resulting effect?

17. What is the main benefit of conventional type landing gear?

18. Why are ground loops common on conventional landing gear?

19. Describe the cause(s) of dissymmetry of lift.

20. What is the NOTAR antitorque system and how does it work?

Multiple Choice Questions

1. The study that calculates the loads that every part of an aircraft must carry is known as
a. Stress analysis
b. Tension analysis
c. Load testing

2. The material’s internal resistance or counterforce that opposes deformation is called
a. Rigidity
b. Strength
c. Stress

3. What type of stress resists a crushing force?
a. Tension
b. Compression
c. Torsion

4. What type of stress is a combination of compression and tension?
a. Torsion
b. Shear
c. Bending

5. What type of construction method is used for most aluminum aircraft constructions?
a. Monocoque
b. Semimonocoque
c. Truss

6. What is the angle called that is made between the fuselage and the horizontal plane of the wing?
a. Angle of attack
b. Wing dihedral
c. Angle of incidence

7. What is the principle structural member of the wing?
a. Spars
b. Ribs
c. Stringers

8. How is the load transferred from the skin and the stringers to the spars?
a. Stiffeners
b. Caps
c. Ribs

9. Where are wing butt ribs located?
a. Forward of the front spar
b. In between the front and rear spar
c. At the inboard edge of the wing

10. What is the purpose of a fairing?
a. Allows for smooth airflow between the wing and fuselage
b. Provide a strong and secure method for attaching the wing to the fuselage
c. Receives compression loads that tend to force the wing spars together

11. What are the names of the movable flight control surfaces on the empennage?
a. Horizontal stabilizer and elevator
b. Vertical stabilizer and rudder
c. Elevator and rudder

12. What flight control surface movement causes the aircraft to roll?
a. Aileron
b. Elevator
c. Rudder

13. What type of movement does the rudder control?
a. Roll
b. Pitch
c. Yaw

14. What is a common design feature of ailerons to prevent flutter?
a. Hinge points aft of the leading edge
b. Hinge points forward of the leading edge
c. Hinge points at the leading edge

15. As the aileron moves downward, what happens to the camber and lift respectively?
a. Camber increases, lift decreases
b. Camber decreases, lift decreases
c. Camber increases, lift increases

16. How is the elevator controlled from the cockpit?
a. Side‐to‐side motion of the control yoke
b. Push and pull motion of the control yoke
c. Depressing of foot‐operated pedals

17. Which two types of control surfaces reduce the force needed to move a primary control surface?
a. Anti‐balance and servo tabs
b. Trim and balance tabs
c. Slats and spoilers

18. What type of secondary flight control decreases lift?
a. Slats
b. Slots
c. Spoilers

19. Which control surface can be operated independently of the flaps?
a. Leading edge flaps
b. Slats
c. Neither A or B

20. Spoilers may be fully deployed on both wings at the same time for what purpose?
a. Augment aileron function
b. Decrease lift in‐flight
c. Speed brakes

21. What flight control tabs move in same direction as the control surface it is attached to?
a. Trim
b. Spring
c. Anti‐balance

22. How are flight control surfaces moved on an aircraft that is equipped with a fly‐by‐wire system?
a. Electrical input only
b. Hydraulic actuators and electrical input
c. Control cables only

23. What type of device is used as a barrier on the upper surface of the wing to reduce the tendency of the wing to stall at low flight speeds?
a. Stall fence
b. Vortex generator
c. Gap seals

24. Where is the center of gravity located on an aircraft with a tricycle landing gear?
a. Forward of the main wheels
b. Aft of the main wheels
c. In‐line with the main wheels

25. Fuselage stations are numbered in inches from
a. The buttock line
b. Reference datum
c. Water line

26. is a measurement forward or aft of the front spar and perpendicular to the water line
a. Aileron station
b. Flap station
c. Nacelle station

27. Where can one find information on panel numbering and the location of components under each panel?
a. AC 43.13
c. Maintenance manual

28. How are main rotors of helicopters classified?
a. The transmission used to power the rotors
b. Blade attachment and motion relative to the hub
c. Swash plate and pitch change units attached to the blade

29. How is the pitch of the rotor blades changed in a rigid rotor system?
a. Feathering hinges
b. Coning hinges
c. Teetering hinges

30. What is the windspeed and lift developed by the advancing blade in relation to the retreating blade?
a. Greater windspeed, less lift
b. Slower windspeed, less lift
c. Greater windspeed, more lift 

History of Aircraft Structures
Major Structural Stresses
Fixed-Wing Aircraft
Primary Flight Control Surfaces and Dual Purpose Flight Control surfaces
Secondary or Auxiliary Control Surfaces
Other Wing Features
Landing Gear
Location Numbering Systems
Access and Inspection Panels Helicopter Structures