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Question 1. Which design philosophy primarily relies on the ability of a structure to sustain damage without catastrophic failure? A) Safe‑life design B) Fail‑safe design C) Weight‑optimised design D) Redundancy‑free design Answer: B Explanation: Fail‑safe design incorporates redundancy so that damage does not lead to immediate failure. Question 2. In a semi‑monocoque fuselage, the primary load‑bearing members are: A) Only the skin B) Longerons and stringers together with the skin C) Bulkheads alone D) Frames only Answer: B Explanation: Semi‑monocoque uses both internal frames (longerons, stringers) and stressed skin to share loads. Question 3. What is the typical material used for aircraft wing spar caps because of its high strength‑to‑weight ratio? A) 2024‑T3 aluminum alloy B) 6061‑T6 aluminum alloy C) 7075‑T6 aluminum alloy D) 4130 steel Answer: C Explanation: 7075‑T6 offers superior tensile strength while remaining lightweight, ideal for spar caps.
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Question 4. Which of the following loading conditions produces a pure torsional stress in a wing spar? A) Bending moment only B) Shear force only C) Aerodynamic twisting moment D) Axial compression Answer: C Explanation: An aerodynamic twisting moment generates torsion about the spar’s longitudinal axis. Question 5. The “water line” on an aircraft drawing corresponds to: A) The longitudinal centreline of the fuselage B) The vertical centreplane of the aircraft C) The intersection of the water surface with the hull in a seaplane D) The reference line used for wing station measurements Answer: D Explanation: Water line is a datum used for locating stations along the wing’s chordwise direction. Question 6. Which aluminum alloy is most commonly used for aircraft skin due to its excellent corrosion resistance? A) 2024 B) 6061 C) 7075 D) 3003 Answer: B Explanation: 6061‑T6 provides good corrosion resistance and formability, making it suitable for skin. Question 7. A “I‑beam” wing spar is preferred over a “C‑channel” spar when: A) Maximum torsional rigidity is required
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D) Jo‑bolt Answer: B Explanation: Blind rivets are installed using a tool that expands the rivet from the visible side. Question 11. When spacing rivets along a lap joint, the recommended transverse pitch is typically: A) 0.5 times the rivet diameter B) 1.0 times the rivet diameter C) 2.0 times the rivet diameter D) 3.0 times the rivet diameter Answer: C Explanation: A transverse pitch of about two rivet diameters ensures adequate shear transfer and avoids skin tearing. Question 12. A Huckbolt is primarily used for: A) Permanent structural fastening of thin sheet metal B) High‑strength, high‑shear applications where a solid rivet cannot be used C) Quick removal of panels for inspection D) Joining composite to metal structures Answer: B Explanation: Huckbolts provide high shear strength and are often used where rivets would be inadequate. Question 13. Interference fit in aircraft assembly means: A) A clearance fit allowing free movement B) A press fit where the fastener is slightly larger than the hole C) A slip fit for easy disassembly D) A welded joint Answer: B
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Explanation: Interference (press) fit requires the fastener to be forced into a slightly undersized hole. Question 14. Carbon‑fiber reinforced polymer (CFRP) is preferred over fiberglass when: A) Cost is the primary concern B) High impact resistance is needed C) Maximum strength‑to‑weight ratio is required D) Easy repairability is desired Answer: C Explanation: CFRP offers superior specific strength and stiffness compared to fiberglass. Question 15. Nomex honeycomb core is most commonly used in: A) Primary load‑bearing wing spars B) Aircraft floor panels and bulkheads C) High‑temperature engine components D) Landing gear struts Answer: B Explanation: Nomex honeycomb provides lightweight stiffness ideal for floor panels and bulkheads. Question 16. Acrylic windshields are more susceptible to damage from: A) UV radiation B) Impact from bird strikes C) High‑temperature flame exposure D) Chemical solvents Answer: B Explanation: Acrylic is less impact‑resistant than polycarbonate, making bird strikes a concern. Question 17. In damage assessment, a “repairable by insertion” classification indicates: A) The damaged area can be patched with a thin sheet
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Answer: A Explanation: Tensile stress combined with a corrosive medium promotes stress corrosion cracking. Question 21. Static balancing of a control surface is performed to: A) Reduce aerodynamic drag B) Prevent flutter at high speeds C) Increase control surface deflection range D) Simplify rigging procedures Answer: B Explanation: Proper static balance raises the flutter margin by aligning mass and aerodynamic centers. Question 22. A turnbuckle in a cable system is used to: A) Change cable length for tension adjustment B) Provide electrical grounding C) Connect hydraulic lines D) Act as a failsafe release device Answer: A Explanation: Turnbuckles allow fine adjustment of cable tension by changing effective length. Question 23. The primary function of an oleo‑pneumatic landing‑gear shock absorber is to: A) Provide hydraulic braking force B) Convert kinetic energy to heat during touchdown C) Store fuel for auxiliary power D) Act as a retractable actuator Answer: B Explanation: Oleo‑pneumatic struts dampen landing loads by converting kinetic energy into hydraulic fluid heat.
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Question 24. An over‑center link in a landing‑gear retraction system provides: A) A mechanical lock that resists accidental extension B) A hydraulic pressure boost C) A cushioning effect during gear extension D) An electrical feedback signal Answer: A Explanation: Over‑center geometry creates a self‑locking position when gear is fully retracted. Question 25. Split‑rim wheels are preferred on high‑performance aircraft because: A) They are lighter than solid rims B) They allow larger brake discs without increasing wheel diameter C) They simplify tire inflation procedures D) They reduce aerodynamic drag Answer: B Explanation: Split rims enable larger brake assemblies while maintaining a compact wheel size. Question 26. Liquid penetrant testing is most effective for detecting: A) Subsurface cracks in thick metal B) Surface‑breaking defects on non‑porous materials C) Internal voids in composites D) Corrosion under paint on aluminum Answer: B Explanation: Penetrant testing reveals surface discontinuities on smooth, non‑porous surfaces. Question 27. After a hard landing, which structural area should be inspected first for possible damage? A) Wing leading edge B) Nose gear strut
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Explanation: Safe‑life design specifies a service life after which parts must be removed regardless of condition. Question 31. Which of the following is a characteristic of a monocoque fuselage? A) Load is carried primarily by internal frames B) The skin alone carries most structural loads C) It uses a honeycomb core for stiffness D) It requires extensive rivet patterns for reinforcement Answer: B Explanation: Monocoque relies on the outer skin to bear the majority of stresses. Question 32. The primary advantage of using titanium over aluminum in high‑temperature zones is: A) Lower cost B) Higher electrical conductivity C) Greater strength retention at elevated temperatures D) Easier machining Answer: C Explanation: Titanium maintains strength at temperatures where aluminum would lose stiffness. Question 33. In a wing rib, the “spar web” primarily resists which type of load? A) Bending moment B) Shear force C) Torsional moment D) Axial compression Answer: B Explanation: The web of an I‑section spar is designed to carry shear loads. Question 34. A “flap” is considered a secondary control surface because:
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A) It is not required for basic flight control B) It directly controls pitch attitude C) It is used only during take‑off and landing D) It provides thrust augmentation Answer: A Explanation: Flaps augment lift/drag but are not essential for primary control of roll, pitch, or yaw. Question 35. When performing a dynamic balance check on a rudder, the technician must verify: A) That the rudder’s center of gravity lies exactly at the hinge line B) That the mass moment of inertia about the hinge does not exceed design limits C) That the rudder is free of any corrosion D) That the hydraulic actuator operates within 0.2 s Answer: B Explanation: Dynamic balance ensures the rudder’s inertia does not induce flutter. Question 36. The term “edge distance” in rivet placement refers to: A) The spacing between adjacent rivets B) The distance from the rivet centre to the nearest edge of the material C) The length of the rivet shank D) The angle of the rivet head relative to the surface Answer: B Explanation: Edge distance is measured from rivet centre to the nearest sheet edge to prevent tear‑out. Question 37. A “CherryMAX” rivet is distinguished by: A) Its ability to be installed blind from either side B) A built‑in washer that eliminates the need for a separate backing plate C) Its use only in composite structures D) Its reversible installation feature
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Question 41. A “stringer” in a fuselage primarily serves to: A) Transfer loads between bulkheads B) Provide longitudinal stiffness and prevent skin buckling C) Act as a conduit for wiring D) Support the landing gear attachment Answer: B Explanation: Stringers stiffen the skin longitudinally, reducing susceptibility to buckling. Question 42. Which of the following core materials is most suitable for high‑temperature applications? A) Nomex honeycomb B) Aluminum honeycomb C) PVC foam D) Balsa wood Answer: B Explanation: Aluminum honeycomb retains strength at higher temperatures compared with organic cores. Question 43. When a wing experiences a “torsional divergence,” the primary corrective action is to: A) Increase wing twist angle B) Add torsional stiffness through spar redesign or additional ribs C) Reduce wing sweep angle D) Install larger ailerons Answer: B Explanation: Torsional divergence is mitigated by increasing structural torsional rigidity. Question 44. The “bolt torque” required for a Jo‑bolt is higher than for a standard bolt because: A) Jo‑bolts have a larger head diameter
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B) The joint is designed to be load‑carrying in shear, requiring higher clamping force C) Jo‑bolts are made from softer material D) They are always installed in composite structures Answer: B Explanation: Jo‑bolts are used where the bolt itself carries shear, demanding higher preload. Question 45. In a hydraulic landing‑gear system, the “accumulator” serves to: A) Store hydraulic fluid for emergency gear extension B) Filter contaminants from the fluid C) Provide cooling to the hydraulic lines D) Act as a pressure relief valve Answer: A Explanation: Accumulators store pressurized fluid that can be released to extend gear if normal power is lost. Question 46. A “fabric‑covered” aircraft wing is typically finished using: A) Epoxy resin coating B) Ceconite or Dacron fabric doped with nitrate‑based sealant C) Aluminum sheeting D) Carbon‑fiber wrap Answer: B Explanation: Traditional fabric covering uses Ceconite/Dacron treated with nitrate dopes for tautness and protection. Question 47. The “flap gap” on a wing must be kept within tight tolerances because: A) Excessive gap reduces lift and increases drag B) Gaps cause structural fatigue in the flap hinges C) They interfere with the aircraft’s navigation system
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Question 51. Which of the following is a common cause of “fretting corrosion” in aircraft structures? A) High‑temperature exposure B) Repeated micro‑movement between two contacting surfaces under load C) Direct exposure to saltwater spray D) Use of dissimilar alloys without a barrier Answer: B Explanation: Fretting occurs from small oscillatory motions that wear protective films, leading to corrosion. Question 52. A “split‑rim” wheel requires which specific maintenance practice? A) Regular balancing of each half separately B) Tightening the wheel bolts to a specified torque after each brake service C) Applying a special anti‑corrosion coating to the rim interior only D) Replacing the entire wheel after 500 flight hours Answer: B Explanation: Split‑rim wheels must have the split bolts torqued correctly to maintain structural integrity. Question 53. In a composite wing spar, the “fiber orientation” of 0°/90° refers to: A) Fibers aligned parallel and perpendicular to the spar’s longitudinal axis B) Fibers placed at ±45° to the spar axis C) Random fiber distribution throughout the laminate D) The angle of the spar relative to the fuselage centerline Answer: A Explanation: 0° fibers run along the length, 90° fibers run across, providing strength in both directions. Question 54. When a “fail‑safe” structure is inspected, which condition is acceptable?
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A) Any crack larger than 0.1 in must be repaired immediately B) Minor damage that does not compromise the load path can be left unrepaired C) All damage must be repaired regardless of size D) Only visual inspection is required, no measurements needed Answer: B Explanation: Fail‑safe design tolerates limited damage because alternate load paths exist. Question 55. The “bending moment” at the wing root is greatest because: A) The wing experiences the highest aerodynamic pressure at the tip B) Loads from the entire wing are transferred to the root, creating a larger moment arm C) The root is always made of a stronger material D) The wing root is the only location where the spar is attached to the fuselage Answer: B Explanation: The root carries the cumulative lift forces acting over the wing span, generating the largest moment. Question 56. A “tightening sequence” for a multi‑bolt flange is used to: A) Reduce the number of required bolts B) Ensure even distribution of clamping force and prevent distortion C) Allow bolts to be installed faster D) Increase the overall weight of the assembly Answer: B Explanation: Proper sequence avoids uneven stresses that could deform the joint. Question 57. Which property of magnesium alloys makes them less common for primary airframe structures? A) High density B) Poor corrosion resistance
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Explanation: Magnetic particle testing requires a magnetic field in ferromagnetic material to reveal surface or near‑surface defects. Question 61. Which of the following is a typical symptom of “wing flutter” developing? A) Decrease in engine RPM B) Rapid, uncontrolled oscillation of the wing at certain speeds C) Sudden loss of cabin pressure D) Increased fuel consumption Answer: B Explanation: Flutter is an aeroelastic instability manifested as self‑excited wing vibration. Question 62. The “pitch” of a rivet pattern refers to: A) The angle of the rivet head relative to the sheet B) The center‑to‑center spacing of rivets along the line of the joint C) The distance from the rivet to the nearest edge D) The number of rivets per inch Answer: B Explanation: Pitch is the linear spacing between consecutive rivet centers. Question 63. An “electro‑plated” aluminum component gains improved corrosion resistance primarily because: A) The plating adds a sacrificial zinc layer B) The process fills micro‑cracks in the alloy surface C) It creates a uniform, protective oxide layer D) It changes the alloy composition to stainless steel Answer: C Explanation: Electro‑plating forms a consistent protective coating that resists corrosion.
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Question 64. In a “trunnion‑mounted” landing‑gear design, the trunnion acts as: A) The hydraulic pump for gear actuation B) The pivot point allowing gear rotation during retraction and extension C) The primary load‑bearing member for side loads D) The sensor for gear position feedback Answer: B Explanation: The trunnion provides the rotational axis for the gear assembly. Question 65. When a composite repair requires “hot bonding,” the process involves: A) Curing the resin at ambient temperature with a vacuum bag B) Applying heat to activate an adhesive film that bonds the patch to the structure C) Using a chemical solvent to dissolve the existing matrix D) Injecting a low‑viscosity resin under pressure Answer: B Explanation: Hot bonding uses heat‑activated adhesives to join composite patches. Question 66. The term “frame” in a semi‑monocoque fuselage most closely corresponds to: A) A bulkhead that runs circumferentially, providing shape and stiffness B) A longitudinal stringer C) The outer skin panel D) The wing attachment fitting Answer: A Explanation: Frames (or formers) are circumferential members that define fuselage cross‑section shape. Question 67. Which of the following is the most common cause of “stress‑relief cracking” in aluminum alloy after machining? A) Over‑tightening of fasteners B) Rapid cooling of a hot‑worked part causing residual tensile stresses
