T 2026 Pre-Mock Board Exam: Aircraft Structures and Design

1. A spar is tapered from root to tip because

A. shear forces are greatest at the root.

B. bending moment is greatest at the root.

C. centre of lift occurs close to the root.

D. to reduce structural weight as possible.

B. bending moment is greatest at the root.

2. A biplane has positive stagger when

A. the upper wing is closer to the nose than the lower wing.

B. the upper wing has the greater angle than the lower wing.

C. the lower wing is closer to the nose than the upper wing.

D. the lower wing has the greater angle than the upper wing.

A. the upper wing is closer to the nose than the lower wing.

3. The whole Design philosophy of an Aircraft is termed as _____

A. design evaluation

B. anatomy

C. design wheel

D. sizing

C. design wheel

4. The wing bending moment in this condition produce the highest compressive stresses in the lower forward region of the wing cross section and the highest tensile stresses in the upper aft region of the wing cross section.

A. Positive High Angle of Attack

B. Positive Low Angle of Attack

C. Negative High Angle of Attack

D. Negative Low Angle of Attack

C. Negative High Angle of Attack

5. A general aviation aircraft is flying with crew load of 115 lb, payload of 220 lb and fuel weight of 100 lb. Find out the design take-off gross weight of the aircraft, given 95 lb empty weight.

A. 435 lb

B. 241 lb

C. 530 lb

D. 500 lb

C. 530 lb

6. Which is not a best way to improve the stall characteristics of airfoils?

A. Changing the angle of attack of the wing tip airfoils or a different wing tip airfoil.

B. Stall characteristics for thinner airfoils can be improved with various leading-edge devices such as slots, slats, leading-edge flaps, and Krueger flaps.

C. Active methods such as suction or blowing.

D. Increase the leading edge radius.

D. Increase the leading edge radius.

7. The main function of a swept wing is:

A. for structural reasons

B. to produce induced drag

C. to increase the critical Mach number

D. to produce more lift

C. to increase the critical Mach number

8. What is an arresting landing gear?

A. It is equipped on carrier-type aircraft that helps accelerate the aircraft when it takes off on an aircraft carrier.

B. It allows the aircraft to be secured to the carrier deck for full-power turnup of the engine prior to takeoff.

C. It is designed to absorb the shock that would otherwise be transmitted to the airframe during landing, taxiing, and takeoff.

D. It has a hook and a snubber.

D. It has a hook and a snubber.

9. Avionics systems are an example of ____ weight.

A. empty

B. crew

C. passenger

D. payload

A. empty

10. Which best describes the stalling characteristics of fat airfoils?

A. Flow separates near the nose at a very small angle of attack, but reattaches itself so that little effect is felt.

B. Has a thickness to chord ratio less than 0.06

C. The flow separates from the nose at a small angle and reattaches almost immediately.

D. Stall from the trailing edge.

D. Stall from the trailing edge.

11. Determine the value of stress produced if the body is subjected to a force of 100 N and a cross-sectional area of 10 sqm.

A. 15 MPa

B. 10 Pa

C. 20 GPa

D. 27 Pa

B. 10 Pa

12. What would be the margin of safety of normal category aircraft with a computed limit load of 2400 lbs maximum takeoff weight?

A. 1.00

B. 1.25

C. 1.50

D. 0.50

D. 0.50

13. The following statements below best describe the conceptual design phase except:

A. A concrete goal is established toward which the designers are aiming.

B. The overall shape, size, weight, and performance of the new design are determined.

C. Lofting is carried out.

D. Layout of the airplane configuration is produced.

C. Lofting is carried out.

14. It is the angle of concern in supersonic flight.

A. leading edge sweep.

B. quarter chord line sweep.

C. effective angle of attack.

D. all of the above.

A. leading edge sweep.

15. Which of the following best describes the cabin arrangement for a commercial aircraft?

A. Aisle is the distance from the back of one seat to the back of the next.

B. Pitch is the height from the floor to the roof over the seat.

C. Headroom is the passage between two rows of seats.

D. Cabin arrangement for a commercial aircraft is determined by marketing requirements.

D. Cabin arrangement for a commercial aircraft is determined by marketing requirements.

16. This provides an exact, mathematical definition of the entire aircraft including such minor details as the intake and exhaust ducts for the air conditioning.

A. Lofting

B. Inboard profile

C. Isometric drawing

D. Production lofting

D. Production lofting

17. As a rule of thumb, all inlets should be located a height above the runway equal to:

A. at least 80% of the inlet's height if using a low bypass ratio engine.

B. at least 50% of the inlet's height if using a low bypass ratio engine.

C. at least 80% of the inlet's height if using a high bypass ratio engine.

D. at least 40% of the inlet's height if using a high bypass ratio engine.

A. at least 80% of the inlet's height if using a low bypass ratio engine.

18. What is the positive ultimate load factor of a FAR Part 23 acrobatic type aircraft?

A. 9.0

B. 4.4

C. 6.0

D. 6.6

A. 9.0

19. Find the design takeoff weight of the flying boat with the following specifications:

Pilot = 180 lb

Co-Pilot = 170 lb

Flight Engineer = 165 lb

Maximum Gross Payload = 200,000 lb

Empty Weight Fraction = 0.75

Total Mission Weight Fraction = 0.90

A. 2,000,000 lb

B. 1,800,000 lb

C. 1,600,000 lb

D. 1,400,000 lb

D. 1,400,000 lb

20. How do you best describe the criticality of a secondary structure?

A. Its integrity is essential in maintaining the overall flight safety of the aircraft

B. If this structure is severely damaged, the aircraft cannot fly.

C. It is used mainly to provide enhanced aerodynamics.

D. Its failure would not significantly affect operation of the aircraft.

C. It is used mainly to provide enhanced aerodynamics.

21. As a rule of thumb, how much is the least area of the rudder that should be out of the wake generated by the horizontal stabilizer?

A. 50%

B. 15%

C. 66%

D. 33%

D. 33%

22. A FAR Part 23 utility aircraft is configured to have an angle of attack of 1.7 degrees with an estimated forward airspeed of 70 knots during approach. What should be corresponding overnose vision angle for the design of its cockpit?

A. 6.5 degrees

B. 8.5 degrees

C. 11.3 degrees

D. 4.7 degrees

A. 6.5 degrees

23. The most widely used low-drag wing tip. This is a sharp-edged wing tip with the surface continuing the upper surface of the wing. The lower surface is "undercut" and canted approximately 30 deg to the horizontal.

A. Winglet

B. Swept

C. Drooped

D. Hoerner

D. Hoerner

24. Which of the following practices is not conducted for each rotor blade of a normal category rotorcraft?

A. There must be means for venting the internal pressure of the blade.

B. Drainage holes must be provided for the blade.

C. The blade must be designed to prevent water from becoming trapped in it.

D. Provide a margin of positive stability great enough to minimize the probability of capsizing.

D. Provide a margin of positive stability great enough to minimize the probability of capsizing.

25. What is the never exceed speed of a FAR Part 23 utility aircraft with a design cruising speed of 100 knots?

A. 90 knots

B. 250 knots

C. 110 knots

D. 190 knots

C. 110 knots

VCdes = (0.9)Vmax

Note that Vmax = Vne (never exceed speed)

Vmax = VCdes (1/0.9)
Vmax = 100 (1/0.9)
Vmax = 111.11 knots

26. Which is not a best way to improve the stall characteristics of airfoils?

A. Changing the angle of attack of the wing tip airfoils or a different wing tip airfoil.

B. Stall characteristics for thinner airfoils can be improved with various leading-edge devices such as slots, slats, leading-edge flaps, and Krueger flaps.

C. Active methods such as suction or blowing.

D. Increase the leading edge radius.

D. Increase the leading edge radius.

27. Among the choices below, which is not a function of secondary flight surfaces?

A. Reduce the force required to actuate the primary controls.

B. Change the speed of the aircraft in flight.

C. Reduce take-off speed or shorten the length of the take-off roll.

D. Trim and balance the aircraft in flight.

C. Reduce take-off speed or shorten the length of the take-off roll.

28. Which of the following about the keel beam is true?

A. It is located through the center section of the wing.

B. It supports the wheel well area where a maximum amount of bending can occur and can transport wing loads.

C. It is made up of tension chords and a shear web structure containing stiffeners.

D. It mainly supports cabin pressurization and can absorb the normal loads of the seat tracks and floor panels.

B. It supports the wheel well area where a maximum amount of bending can occur and can transport wing loads.

29. If my factor of safety is 2 and the design load of my aircraft is 1000 N, then at which value of ultimate load can my aircraft withstand without breaking?

A. 9 N

B. 2 kN

C. 1208 kN

D. 1.208 kN

B. 2 kN

30. If an aircraft could be designed with a volume plot shaped like the Sears-Haack volume distribution, it would have the minimum wave drag at

A. M = 0.8

B. M = 0.9

C. M = 1.0

D. M = 1.2

C. M = 1.0

31. An airfoil with a symmetric profile has a pitching moment about the aerodynamic center of 13 Nm at 4° AOA. Determine the pitching moment at the same point if AOA is increased by 8°.

A. 5 Nm

B. 8 Nm

C. 13 Nm

D. 13 Ncm

C. 13 Nm

Given, a symmetric airfoil.
Pitching moment PM1 = 13 Nm at AOA = 4°.
AOA is increased by 8°, New AOA = 4+8 = 12°.

Now PM1 is acting through aerodynamic center. PM will be independent of AOA at aerodynamic center.

Hence, at 12° pitching moment will not change.

Hence, at same point at 12° PM2 = PM1 = 13 Nm.

32. An aircraft is cruising with a lift of 150 N. Find the weight of the aircraft.

A. 0.150 kN

B. 150 kN

C. 123 N

D. 15 kN

A. 0.150 kN

33. For a FAR Part 25 aircraft with a passenger capacity of 550, the minimum number of hand fire extinguishers present should be:

A. 5

B. 6

C. 7

D. 8

C. 7

34. Which of the following best describes the skin of an aircraft fuselage?

A. It is the largest item of the fuselage structure.

B. It cannot prevent buckling.

C. Give shape to the fuselage shell.

D. It can solely withstand cabin pressure.

A. It is the largest item of the fuselage structure.

35. Which best describes the stalling characteristics of moderate thick airfoils?

A. Flow separates near the nose at a very small angle of attack, but reattaches itself so that little effect is felt.

B. Has a thickness to chord ratio less than 0.06

C. The flow separates from the nose at a small angle and reattaches almost immediately.

D. Stall from the trailing edge.

A. Flow separates near the nose at a very small angle of attack, but reattaches itself so that little effect is felt.

36. It is the basic structure of an aircraft and is designed to withstand all aerodynamic forces, as well as the stresses imposed by the weight of the fuel, crew, and payload.

A. Airframe

B. Landing Gear

C. Fuselage

D. Cabin

A. Airframe

37. Which of the following best describes propeller tip speed?

A. Propeller length is not affected by the tip speed.

B. Tip speed cannot exceed sonic speed.

C. Tip speed is the vector sum of the rotational speed and the aircraft's forward speed.

D. All of the above.

C. Tip speed is the vector sum of the rotational speed and the aircraft's forward speed.

38. A NACA 22104 airfoil is operating at AOA = 3°. The lift-coefficient at this AOA is 0.15. Determine the value of angle of attack at designed lift coefficient.

A. 4.36°

B. 4.36 rad

C. 0.05 rad

D. 0.05°

A. 4.36°

Given NACA 22104 airfoil.
AOA = 3°, Cl = 0.15 at 3°
Based on NACA 5-digit series, design Cl = first digit 0.15 = 2 0.15 = 0.3
Now, for thin airfoil lift curve slope = 0.11 per degree
0.11 = (design Cl – Cl at 3°) / (AOA –3°)
0.11 = (0.3-0.15) / (AOA -3°)
0.11 * (AOA - 3°) = 0.15
Hence, at designed Cl, AOA = (0.15 / 0.11) + 3° = 4.36°.

39. It occurs in intentional flight maneuvers in which the air loads on the wing are down or when the airplane strikes sudden downdrafts while in level flight.

A. Positive High Angle of Attack

B. Positive Low Angle of Attack

C. Negative High Angle of Attack

D. Negative Low Angle of Attack

C. Negative High Angle of Attack

40. If the vertical tail has length of 2 m, then find the value of rudder length.

A. 1.8 m

B. 2.8 m

C. 2.0 m

D. 2.5 m

A. 1.8 m

For typical aircraft, the rudder is extended up to 90% of the length of the vertical tail.

Hence, rudder length = 90% of tail length = 90% of 2 m = 0.9 * 2 m = 1.8 m.

41. As a crashworthiness consideration,

A. sloping the upper part of the firewall back will prevent digging in, therefore reducing the deceleration.

B. for a large passenger aircraft, the floor should be supported by braces from the lower part of the fuselage.

C. landing gears should be placed such that they would easily give access to the fuel tank.

D. it is advised to not locate fuel tanks under the fuselage.

D. it is advised to not locate fuel tanks under the fuselage.

42. The S-N curve

A. is a plot of the cyclic stress capacity of a material.

B. specifies the limitations of the aircraft during flight.

C. is the result of the relationship between strain and the number of cycles to failure.

D. shows the effect of the number of cycles to failure until a threshold stress known as the proportional limit.

A. is a plot of the cyclic stress capacity of a material.

43. A prop-driven aircraft has a fuel weight of 650kg. Now, the aircraft is taxiing on runway, after which it has a fuel fraction of 0.975. Determine the fuel used during taxing of aircraft, if the takeoff gross weight is 5000 kg?

A. 125 lb

B. 125 kg

C. 200 lb

D. 250 kg

B. 125 kg

44. It is the highly undesirable tendency where upon reaching an angle of attack (AOA) near stall, to suddenly and uncontrollably increase AOA.

A. Pitch-up

B. Yaw-up

C. Roll-up

D. Hold-up

A. Pitch-up

45. This type of door, hinged at the cabin floor level that opens outward, incorporates integral stairs with a retractable lower step and folding handrail.

A. Towed

B. Bifurcated

C. Winder

D. Clamshell

D. Clamshell

46. What would be the margin of safety of normal category aircraft with a computed limit load of 2400 lbs maximum takeoff weight?

A. 1.00

B. 1.25

C. 1.50

D. 0.50

D. 0.50