Licensing Examination Practice

Illinois Aircraft Mechanic Airframe Licensing Examination Practice Questions And Correct Answers (Verified Answers) Plus Rationales 2026 Q&A | Instant Download Pdf

• What is the primary purpose of a control surface on an aircraft?
• Increase engine efficiency
• Control the aircraft’s attitude
• Reduce fuel consumption
• Support passenger weight

Rationale: Control surfaces such as ailerons, elevators, and rudders

are used to control roll, pitch, and yaw.

• Which type of corrosion occurs between two closely fitting metal

surfaces?

• Uniform corrosion 1 / 4

• Filiform corrosion
• Crevice corrosion
• Galvanic corrosion

Rationale: Crevice corrosion forms in tight spaces where moisture

and contaminants accumulate.

• What is the purpose of a magneto in an aircraft engine?
• Lubricate engine components
• Start the engine
• Provide electrical current to spark plugs
• Measure engine RPM

Rationale: Magnetos generate high voltage for spark plugs

independent of the aircraft electrical system.

• When inspecting aircraft fabric covering, what is an indication that the

fabric needs replacement?

• Slight dirt accumulation
• Patches of rot or tearing
• Minor wrinkles
• Fading color

Rationale: Rot, tears, or severe deterioration compromise the

structural integrity of the airframe.

• What is the purpose of a firewall in an aircraft?
• Reduce aerodynamic drag
• Separate the engine from the cabin 2 / 4

• Protect landing gear components
• Enhance lift

Rationale: Firewalls prevent engine fires from spreading to the

cockpit and cabin.

• What is the most common type of rivet used in aircraft sheet metal

construction?

• Friction rivet
• Blind rivet
• Solid shank rivet
• Threaded rivet

Rationale: Solid shank rivets, such as AN rivets, are widely used for

structural connections.

• What is the purpose of a dihedral angle in wing design?
• Increase fuel capacity
• Improve lateral stability
• Reduce drag
• Enhance engine performance

Rationale: Dihedral angles cause wings to naturally return to level

during roll disturbances.

• What is the primary method for inspecting aircraft structural

components for cracks?

• Visual inspection only
• Non-destructive testing (NDT) 3 / 4

• Stress testing to failure
• Weight measurement

Rationale: NDT methods, such as dye penetrant or eddy current,

detect cracks without damaging parts.

• Which metal is most commonly used in aircraft skins?
• Steel
• Aluminum alloy
• Titanium
• Magnesium

Rationale: Aluminum alloys provide a balance of strength, light

weight, and corrosion resistance.

• What is the function of a trim tab on a control surface?
• Reduce landing gear stress
• Adjust control forces for stable flight
• Protect against corrosion
• Increase lift

Rationale: Trim tabs reduce pilot workload by maintaining desired

control surface positions.

• What is the main purpose of a static discharger on an aircraft?
• Increase engine thrust
• Dissipate static electricity
• Reduce fuel consumption
• Measure airspeed
• / 4