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FAA Aviation Mechanic - Airframe (AMA) study materials
FAA Aviation Mechanic - Airframe (AMA) study resources

FAA Aviation Mechanic - Airframe (AMA) practice questions

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Question 1Airframe Structures

In a semimonocoque fuselage, which longitudinal member carries bending loads?

  1. Frame
  2. Former
  3. Longeron Correct answer.
  4. Bulkhead

Explanation

Longerons run lengthwise and, together with the skin, carry bending and axial loads. Frames and formers are transverse members that maintain shape and carry concentrated loads.

Question 2Airframe Structures

The minimum edge distance for a rivet in aircraft sheet metal is normally

  1. Two rivet diameters Correct answer.
  2. One rivet diameter
  3. Four rivet diameters
  4. Three rivet diameters

Explanation

Standard practice requires an edge distance of at least two rivet diameters to prevent tear-out of the sheet. Greater distance may be used, but less is not acceptable for normal structural repairs.

Question 3Airframe Structures

The primary purpose of applying dope to a fabric-covered aircraft structure is to

  1. Replace rib stitching
  2. Tauten the fabric Correct answer.
  3. Increase porosity
  4. Add color only

Explanation

Dope shrinks as it dries, tightening the fabric, and it also forms a protective film. Color and protection are secondary to the tautening action.

Question 4Airframe Structures

A lengthwise separation of wood fibers along the grain is called a

  1. Knot
  2. Compression failure
  3. Check Correct answer.
  4. Bark pocket

Explanation

A check is a longitudinal separation along the grain, often caused by drying stresses. It differs from a knot, bark pocket, or compression failure.

Question 5Airframe Structures

Galvanic corrosion is most likely to occur where

  1. Aluminum is anodized
  2. Two identical aluminum parts are joined
  3. Aluminum contacts steel in moisture Correct answer.
  4. Paint covers bare aluminum

Explanation

Dissimilar metals in contact with an electrolyte form a galvanic cell, and the more active metal corrodes. Aluminum in contact with steel in moisture is a classic example.

Question 6Airframe Structures

In a true monocoque fuselage, the primary loads are carried by

  1. The skin Correct answer.
  2. Bulkheads only
  3. Internal truss members
  4. Longerons only

Explanation

A monocoque structure relies on the skin to carry primary loads. Semimonocoque construction adds longitudinal and transverse members to help carry those loads.

Question 7Airframe Structures

The main function of wing ribs is to

  1. Attach landing gear
  2. Maintain airfoil shape Correct answer.
  3. Carry fuel only
  4. Carry engine thrust

Explanation

Ribs shape the airfoil and support the skin, transferring loads to the spars. They are not the primary thrust or landing-gear attachment members.

Question 8Airframe Structures

Which rivet head is commonly used where a flush surface is not required?

  1. Flat head
  2. Universal head Correct answer.
  3. Countersunk head
  4. Brazer head

Explanation

The universal head is the common general-purpose rivet head used where aerodynamic smoothness is not needed. A flush surface requires a countersunk head.

Question 9Airframe Structures

A flush patch is normally required when damage is located

  1. In a fuel tank
  2. On an aerodynamic surface Correct answer.
  3. In a non-pressurized area
  4. On a wing spar web

Explanation

A flush patch preserves smooth airflow and is used on aerodynamic surfaces. Fuel tanks may require sealed repairs, and spar webs are structural rather than aerodynamic surfaces.

Question 10Airframe Structures

Rivet pitch is defined as the distance between

  1. Rivet head and shank end
  2. Adjacent rivets in a row Correct answer.
  3. Two rows of rivets
  4. Rivet center and edge of sheet

Explanation

Pitch is the center-to-center spacing of adjacent rivets in the same row. Edge distance is measured from the rivet center to the sheet edge.

Question 11Airframe Structures

Exfoliation corrosion is characterized by

  1. Small circular pits in the surface
  2. Cracks at highly stressed points
  3. White powder on the surface
  4. Layers lifting like a book Correct answer.

Explanation

Exfoliation attacks grain boundaries in rolled or extruded metal, causing layers to lift and separate. It is more severe than ordinary surface corrosion.

Question 12Airframe Structures

A common field method for detecting delamination in a composite laminate is

  1. Dye penetrant inspection
  2. Eddy current inspection
  3. Magnetic particle inspection
  4. Tap testing Correct answer.

Explanation

Tap testing detects changes in sound caused by disbonds or delamination in composites. Magnetic particle and eddy current methods are suited to metals, and dye penetrant detects surface-breaking defects.

Question 13Airframe Structures

The 'T' in 2024-T3 aluminum alloy indicates that the metal has been

  1. Cast and homogenized
  2. As fabricated
  3. Annealed
  4. Solution treated Correct answer.

Explanation

The T temper denotes solution heat treatment, often followed by aging or cold working depending on the specific T number. T3 specifically means solution treated, cold worked, and naturally aged.

Question 14Airframe Structures

Which aluminum alloy is commonly used for heat-treatable aircraft sheet skin?

  1. 1100
  2. 2024 Correct answer.
  3. 5052
  4. 3003

Explanation

2024 is a heat-treatable aluminum-copper alloy widely used for aircraft skin and structural sheet. Alloys 1100, 3003, and 5052 are not heat-treatable in the same way.

Question 15Airframe Structures

In a wing spar, the spar caps are designed primarily to resist

  1. Compression only
  2. Shear
  3. Bending Correct answer.
  4. Torsion only

Explanation

Spar caps carry the tension and compression produced by bending. The spar web carries shear between the caps.

Question 16Airframe Structures

The web of a wing spar primarily carries

  1. Bending tension
  2. Torsion only
  3. Shear Correct answer.
  4. Bending compression

Explanation

The spar web resists shear loads, while the spar caps resist bending tension and compression. Web stiffeners help prevent buckling under shear.

Question 17Airframe Structures

Fuselage stringers primarily serve to

  1. Form airfoil shape
  2. Stiffen the skin Correct answer.
  3. Attach landing gear
  4. Carry concentrated loads

Explanation

Stringers stiffen the skin and carry axial and bending loads, transferring them to frames. They are longitudinal members, not transverse load fittings.

Question 18Airframe Structures

A fuselage bulkhead is designed primarily to

  1. Form the airfoil
  2. Stiffen the skin only
  3. Carry concentrated loads Correct answer.
  4. Carry wing bending

Explanation

Bulkheads carry concentrated loads such as landing-gear or engine-mount loads and may also close pressurized sections. They are not the primary wing-bending members.

Question 19Airframe Structures

A fail-safe aircraft structure is designed so that

  1. Loads bypass a failed member Correct answer.
  2. It never requires inspection at any time
  3. It has only one primary load path
  4. It uses only composite materials

Explanation

Fail-safe design provides multiple load paths or crack-arrest features so that failure of one member does not cause catastrophic failure. It still requires inspection and maintenance.

Question 20Airframe Structures

Damage-tolerance design requires that

  1. Only visual inspection is used
  2. Structure is never repaired
  3. Cracks are ignored until failure
  4. Cracks are tracked by inspection Correct answer.

Explanation

Damage tolerance assumes cracks or flaws may exist and relies on inspection to find them before they reach critical size. Repairs and multiple inspection methods may be used.

Question 21Airframe Structures

In a bonded composite repair, a scarf joint is used to

  1. Seal fuel leaks
  2. Add weight for balance
  3. Taper the repair Correct answer.
  4. Create a flush riveted joint

Explanation

A scarf joint tapers the repair so the adhesive transfers load gradually over a larger area. This reduces stress concentration compared with an abrupt joint.

Question 22Airframe Structures

In bonded honeycomb sandwich, the facesheets primarily carry

  1. Bending torsion
  2. Tension and compression Correct answer.
  3. Shear only
  4. Core crushing

Explanation

Facesheets carry in-plane tension and compression, while the honeycomb core carries shear and stabilizes the faces against buckling.

Question 23Airframe Structures

Rib stitching is used on fabric-covered wings to

  1. Replace the dope finish entirely
  2. Attach the wing spar to the wing
  3. Hold fabric against the ribs Correct answer.
  4. Increase fabric porosity at the surface

Explanation

Rib stitching mechanically holds the fabric to the ribs so it does not lift or shift in flight. Dope tightens the fabric, but stitching provides positive attachment.

Question 24Airframe Structures

In a beam subjected to bending, the neutral axis is the location where

  1. Bending stress is zero Correct answer.
  2. Bending moment is maximum
  3. Tension equals compression
  4. Shear stress is maximum

Explanation

The neutral axis passes through the centroid of the cross section, and bending stress is zero there. Bending stress increases with distance from the neutral axis.

Question 25Airframe Structures

If rivet pitch is too small, the sheet is most likely to

  1. Tear-out between rivets Correct answer.
  2. Buckling of the sheet between rivets
  3. Faster corrosion of the sheet
  4. Loss of flushness at the rivets

Explanation

Too-small pitch leaves little net section between holes, increasing the chance of tear-out or cracking between rivets. Too-large pitch, by contrast, allows the sheet to buckle between fasteners.

Question 26Airframe Structures

In a solid wood aircraft spar, the grain should run

  1. parallel to the spar length Correct answer.
  2. across the width of the spar
  3. randomly to increase strength
  4. at 45 degrees to the spar length

Explanation

Structural wood must have its fibers running lengthwise so they carry tension and compression along the spar. Diagonal or cross grain creates short-grain areas that severely weaken the member.

Question 27Airframe Structures

The primary function of dope applied to aircraft fabric is to

  1. tauten the fabric and seal it from weather
  2. increase the fabric's resistance to fuel Correct answer.
  3. bond the fabric to the wing spar
  4. act as a fireproofing treatment for the fabric

Explanation

Dope is applied to shrink the fabric to a taut condition and to seal the weave against moisture. It is not a fuel barrier or the primary attachment method.

Question 28Airframe Structures

Galvanic corrosion is most likely to occur when

  1. an aluminum part is anodized before painting Correct answer.
  2. two dissimilar metals contact an electrolyte
  3. the metal surface is kept completely free of moisture
  4. a single metal is exposed to dry air

Explanation

Galvanic corrosion requires two dissimilar metals in electrical contact and an electrolyte path between them. Keeping the joint dry or isolating the metals prevents the corrosion cell.

Question 29Airframe Structures

In a semimonocoque fuselage, the longerons primarily carry

  1. only cabin pressure
  2. bending loads Correct answer.
  3. the weight of the cabin floor panels
  4. only torsional loads

Explanation

Longerons are longitudinal members that carry bending loads along the fuselage, while the skin carries shear and pressure loads. Stringers stiffen the skin between longerons.

Question 30Airframe Structures

A fabric punch tester is used to determine

  1. the tautness of the fabric
  2. the porosity of the fabric
  3. the thickness of the dope film
  4. fabric breaking strength Correct answer.

Explanation

A punch tester measures the force required to push through the fabric, which indicates its remaining strength. Tautness is judged by feel or sound, not by a punch tester.

Question 31Airframe Structures

The minimum edge distance for a rivet is measured from the center of the rivet to

  1. the next rivet in the row Correct answer.
  2. the end of the seam
  3. the edge of the sheet
  4. the nearest bend

Explanation

Edge distance is the distance from the center of the rivet hole to the nearest edge of the sheet. It must be large enough to prevent the rivet from tearing out under load.

Question 32Airframe Structures

The bend allowance in sheet metal layout is the

  1. angle of the bend in degrees
  2. distance from bend tangent line to the edge
  3. total width of the sheet Correct answer.
  4. length of material consumed by the bend

Explanation

Bend allowance is the amount of flat material that is used up in forming the bend. It is added to the flat pattern so the finished part has the correct dimensions.

Question 33Airframe Structures

Oxyacetylene welding of 4130 steel tubing requires

  1. a carburizing flame for all joints
  2. a neutral flame to prevent oxidation
  3. an oxidizing flame for deeper penetration
  4. no flux under any condition Correct answer.

Explanation

A neutral flame is used for 4130 so the weld does not pick up excess carbon or oxygen. The flame setting directly affects the strength and ductility of the finished joint.

Question 34Airframe Structures

In a stressed-skin wing, the skin is designed to carry

  1. no loads after riveting
  2. only the aerodynamic pressure acting on it
  3. only torsional loads
  4. tension, compression, and shear Correct answer.

Explanation

In stressed-skin construction, the skin is part of the primary load path and carries tension, compression, and shear. It works together with spars, ribs, and stringers to resist bending and torsion.

Question 35Airframe Structures

Before installing a structural rivet, deburring the hole is important because burrs

  1. increase the grip length of the rivet Correct answer.
  2. improve the fatigue life of the riveted joint
  3. prevent tight joints and initiate cracks
  4. act as a seal against fuel leaks

Explanation

Burrs keep the sheets from pulling together and create stress concentrations that can start fatigue cracks. Deburring allows proper clamping and protects the hole edge.

Question 36Airframe Structures

In a bonded composite repair, the adhesive bond strength depends most on

  1. the color of the resin
  2. the number of fasteners used in the repair
  3. the thickness of the peel ply Correct answer.
  4. proper preparation of the bond surface

Explanation

A bonded repair depends on a clean, properly abraded, and chemically active surface for the adhesive to grip. Surface contamination is a common cause of weak bonds.

Question 37Airframe Structures

Water trapped in a honeycomb sandwich panel is a structural concern because it can

  1. evaporate and strengthen the core
  2. react with the facesheet to form an oxide
  3. improve the dielectric properties of the panel Correct answer.
  4. freeze and expand, damaging the core and bonds

Explanation

Freezing water expands and can crush the honeycomb core or disbond the facesheets. Moisture also adds weight and can promote corrosion in metallic honeycomb.

Question 38Airframe Structures

When a wood spar is repaired with a scarf joint, the scarf should be

  1. as short as possible to conserve material
  2. cut squarely across the grain at 90 degrees
  3. reinforced with rivets through the spar
  4. long enough to develop full strength Correct answer.

Explanation

A scarf joint must have enough length and taper to develop the full strength of the glued joint. A short scarf concentrates stress and is likely to fail.

Question 39Airframe Structures

Lightening holes in aluminum wing ribs are acceptable because

  1. they increase the total load-carrying area Correct answer.
  2. they provide fuel storage space
  3. they remove material from low-stress areas
  4. they eliminate the need for rivets

Explanation

Lightening holes remove material where bending stresses are low, reducing weight without significantly lowering strength. Their size and spacing are controlled by approved design data.

Question 40Airframe Structures

Magnetic particle inspection can be used to detect cracks in

  1. fiberglass fairings Correct answer.
  2. wooden wing ribs
  3. steel parts
  4. aluminum alloy spars

Explanation

Magnetic particle inspection only works on ferromagnetic materials such as steel. It reveals surface and near-surface discontinuities when the part is magnetized.

Question 41Airframe Structures

Dye penetrant inspection is best suited for detecting

  1. internal voids deep within a casting
  2. magnetic flux leakage in steel Correct answer.
  3. surface cracks in nonporous materials
  4. subsurface delamination in composites

Explanation

Dye penetrant reveals surface-breaking discontinuities in clean, nonporous materials. It cannot detect defects that are completely internal or that do not reach the surface.

Question 42Airframe Structures

After removing corrosion from an aluminum surface, the area should be

  1. left bare so it can be inspected
  2. painted with zinc chromate only before riveting
  3. treated with a protective coating such as primer Correct answer.
  4. coated with grease only

Explanation

Aluminum exposed by corrosion removal must be protected with an approved conversion coating or primer. Leaving it bare allows moisture and oxygen to restart the corrosion process.

Question 43Airframe Structures

After repair and repainting of a control surface, it is important to recheck

  1. control surface balance
  2. the landing gear retraction
  3. the cabin pressurization
  4. the fuel quantity in the wing Correct answer.

Explanation

Repair and paint can change the weight and balance of a control surface, which affects flutter resistance. The surface must be rebalanced to stay within approved limits.

Question 44Airframe Structures

Close-tolerance bolts are often installed with an interference fit to

  1. allow the joint to slide freely under load
  2. make disassembly and removal easier
  3. reduce the need for deburring Correct answer.
  4. improve fatigue life of the joint

Explanation

An interference-fit bolt fills the hole tightly and carries load in bearing, which reduces stress concentration and improves fatigue life. It also prevents joint slip.

Question 45Airframe Structures

If rivets are spaced too far apart along a seam, the sheet may

  1. bulge or pucker between fasteners
  2. become too stiff to buckle under load
  3. lose its heat treatment Correct answer.
  4. develop a tighter seal

Explanation

Excessive rivet spacing leaves unsupported sheet between fasteners, allowing the skin to bulge or pucker under load. Proper pitch keeps the sheets tightly together and distributes the load.

Question 46Airframe Structures

A wing torsion box derives most of its torsional stiffness from

  1. the wingtip fairing
  2. the fuel stored inside the integral wing tanks
  3. the closed cell formed by skins and spar webs Correct answer.
  4. the aileron balance weights

Explanation

A closed box formed by the upper and lower skins, spar webs, and ribs resists torsion efficiently. The continuous load path around the closed cell carries shear between the components.

Question 47Airframe Structures

In a riveted joint, the load is transferred from one sheet to another primarily by

  1. tension in the rivets and shear in the sheets Correct answer.
  2. compression in the rivets and tension in the sheets
  3. shear in the rivets and bearing in the sheets
  4. bending in the rivets and torsion in the sheets

Explanation

Rivets in a lap or splice joint act mainly in shear, while the sheets carry bearing stress around the holes. The joint must be designed so neither shear nor bearing strength is exceeded.

Question 48Airframe Structures

A fatigue crack at a rivet hole in a pressurized fuselage is most likely to initiate at

  1. the sealant layer between the sheets
  2. the middle of the sheet between adjacent rivets
  3. the hole edge at the stress concentration
  4. the rivet head on the outside surface Correct answer.

Explanation

The edge of a rivet hole concentrates stress, so fatigue cracks commonly start there under repeated pressurization cycles. Hole quality, deburring, and proper fit improve fatigue life.

Question 49Airframe Structures

A stepped composite repair is designed to

  1. avoid the use of any adhesive
  2. transfer load through a series of bond surfaces
  3. create a smooth aerodynamic finish only
  4. allow the repair to be bolted instead of bonded Correct answer.

Explanation

A stepped repair removes material in stages so each exposed ply can be bonded to a replacement ply. This spreads the load over multiple bond surfaces and restores laminate strength.

Question 50Airframe Structures

The critical buckling stress of a thin wing skin panel can be increased by

  1. removing the stringers from the panel
  2. increasing the unsupported panel length between frames
  3. using a thinner skin of the same alloy
  4. reducing the panel width between stringers Correct answer.

Explanation

Shorter unsupported panel widths raise the buckling stress because buckling resistance depends strongly on panel dimensions. Stringers and ribs are spaced to divide the skin into smaller, stiffer panels.