Airframe: Sheet Metal

When repairing puncture-type damage of a metal faced laminated honeycomb panel, the edges of the doubler should be tapered to A. two times the thickness of the metal. B. 100 times the thickness of the metal. C. whatever is desired for a neat, clean apperance.

B. 100 times the thickness of the metal.

Which of the following are generally characteristic of carbon/graphite fiber composites? 1. flexibility. 2. stiffness. 3. high compressive strength. 4. corrosive effect in contact with aluminum. 5. ability to conduct electricity. A. 1 and 3. B. 2, 3, and 4. C. 1, 3, and 5.

B. 2, 3, and 4.

What should be the included angle of a twist drill for soft metals? A. 118° B. 90° C. 65°

B. 90°

Which part (s) of a semi-monocoque fuselage prevents(s) tension and compression from bending the fuselage? A. The fuselage covering B. Longerons and stringer C. Bulkheads and skin

B. Longerons and stringer

Which statement is true regarding a cantilever wing? A. It has nonadjustable lift struts B. No external bracing is needed C. It requires only one lift strut on each side

B. No external bracing is needed

Which of the following need not ne considered when determining minimum rivet spacing? A. Rivet diameter B. Rivet length C. Type of material being riveted

B. Rivet length

The classification for high tensile strength fiberglass used in aircraft structures is A. E. B. S. C. G.

B. S.

A well-designed rivet joint will subject the rivets to A. Compressive loads B. Shear loads C. Tension loads

B. Shear loads

Which is considered good practice concerning the installation of acrylic plastics? A. when nuts and bolts are used, the plastic should be installed hot and tightened to a firm fit before the plastic cools. B. when rivets are used, adequate spacer or other satisfactory means to prevent excessive tightening of the frame to the plastic should be provided. C. when rivets or nuts and bolts are used, slotted holes are not recommended.

B. When rivets are used, adequate spacer or other satisfactory means to prevent excessive tightening of the frame to the plastic should be provided.

Clad aluminum alloys are used in aircraft because they A. can be heat treated much easier than the other forms of aluminum. B. are less subject to corrosion than uncoated aluminum alloys. C. are stronger than unclad aluminum alloys.

B. are less subject to corrosion than uncoated aluminum alloys.

Threaded rivets (Rivnuts) are commonly used to A. join two or more pieces of sheet metal where shear strength is desired. B. attach parts or components with screws to sheet metal. C. join two or more pieces of sheet metal where bearing strength is desired.

B. attach parts or components with screws to sheet metal.

Cabin upholstery materials installed in current standard category airplanes must A. be fireproof. B. be at least flame resistant. C. meet the requirements prescribed in Part 43.

B. be at least flame resistant.

Rivet pitch is the distance between the A. center of rivets in adjacent rows B. center of adjacent rivets in the same row C. heads of rivets in the same row

B. center of adjacent rivets in the same row

A factor which determines the minimum space between rivets is the A. length of the rivets being used B. diameter of the rivets being used C. thickness of the material being riveted

B. diameter of the rivets being used

A rivet set used to drive MS20470 rivets should A. have the same radius as the rivet head B. have a slightly greater radius than the rivet head C. be nearly flat on the end, with a slight radius on the edge to prevent damage to the sheet being riveted

B. have a slightly greater radius than the rivet head

One of the best ways to assure that a properly prepared batch of matrix resin has been achieved is to A. perform a chemical composition analysis. B. have mixed enough for a test sample. C. test the viscosity of the resin immediately after mixing.

B. have mixed enough for a test sample.

Longitudinal (fore and aft) structural members of a semi-monocoque fuselage are called A. spars and ribs. B. longerons and stringers. C. spars and stringers.

B. longerons and stringers.

When comparing the machining techniques for stainless steel sheet material to those for aluminum alloy sheet, it is normally considered good practice to drill the stainless steel at a A. higher speed with less pressure applied to the drill. B. lower speed with more pressure applied to the drill. C. lower speed with less pressure applied to the dirll.

B. lower speed with more pressure applied to the drill.

Metal fasteners used with carbon,graphite composite structures A. may be constructed of any of the metals commonly used in aircraft fasteners. B. must be constructed of material such as titanium or corrosion resistant steel. C. must be constructed of high strength aluminum-lithium alloy.

B. must be constructed of material such as titanium or corrosion resistant steel.

Superficial scars, scratches, surface abrasion, or rain erosion on fiberglass laminates can generally be repaired by applying A. a piece or resin-impregnated glass fabric facing. B. one or more coats of suitable resin (room temperature catalyzed) to the surface. C. a sheet of polyethylene over the abraded surface and one or more coats of resin cured with infrared heat lamps.

B. one or more coats of suitable resin (room temperature catalyzed) to the surface.

(1) When performing a ring (coin tap) test on composite structures, a change in sound may be due to damage or to transition to a different internal structure. (2) The extent of separation damage in composite structures is most accurately measured by a ring (coin tap) test. Regarding the above statements, A. both No. 1 and No. 2 are true. B. only No. 1 is true. C. only No. 2 is true.

B. only No. 1 is true.

The part of a replacement honeycomb core that must line up with the adjacent original is the A. cell side. B. ribbon direction. C. cell edge.

B. ribbon direction.

When inspecting a composite panel using the ring test/tapping method a dull thud may indicate A. less than full strength curing of the matrix. B. separation of the laminates. C. an area of too much matrix between fiber layers.

B. separation of the laminates.

The monocoque fuselage relies largely on the strength of A. longerons and formers B. skin or covering C. bulkheads and longerons

B. skin or covering

What is the most common method of cementing transparent plastics? A. heat method. B. soak method. C. bevel method.

B. soak method.

When holes are drilled completely through Plexiglas, a A. standard twist drill should be used. B. specially modified twist drill should be used. C. wood drill should be used.

B. specially modified twist drill should be used.

The strength and stiffness of a properly constructed composite buildup depends primarily on A. a 60 percent matrix to 40 percent fiber ration. B. the orientation of the plies to the load direction. C. the ability of the fibers to transfer stress to the matrix.

B. the orientation of the plies to the load direction.

When installing transparent plastic enclosures which are retained by bolts extending through the plastic material and self-locking nuts, the nuts should be A. tightened to a firm fit, plus one full turn. B. tightened to a firm fit, then baked off one full turn. C. tightened to a firm fit.

B. tightened to a firm fit, then baked off one full turn.

Which procedure is correct when using a reamer to finish a drilled hole to the correct size? A. turn the reamer in the cutting direction when enlarging the hole and in the opposite direction to remove from the hole. B. turn the reamer only in the cutting direction. C. apply considerable pressure on the reamer when starting the cut and reduce the pressure when finishing the cut.

B. turn the reamer only in the cutting direction.

When repairing large, flat surfaces with polyester resins, warping of the surface is likely to occur. One method of reducing the amount of warpage is to A. add an extra amount of catalyst to the resin. B. use short strips of fiberglass in the bonded repair. C. use less catalyst than normal so the repair will be more flexible.

B. use short strips of fiberglass in the bonded repair.

Cherrymax and Olympic-Lok rivets A. utilize a rivet gun, special rivet set, and bucking bar for installation. B. utilize a pulling tool for installation. C. may be installed with ordinary hand tools.

B. utilize a pulling tool for installation

Composite fabric material is considered to be the strongest in what direction? A. fill. B. warp. C. bias.

B. warp.

(Refer to Figure 2) Select the preferred drawing for proper countersinking. A. All are acceptable B. 2 C. 1

C. 1

A potted compound repair on honeycomb can usually be made on damages less than A. 4 inches in diameter. B. 2 inches in diameter. C. 1 inch in diameter.

C. 1 inch in diameter.

A single-lap sheet splice is to be used to repair a section of damaged aluminum skin. If a double row of 1/8 inch rivets is used, the minimum allowable overlap will be A. 1/2 inch. B. 3/4 inch. C. 13/16 inch.

C. 13/16 inch.

When drilling stainless steel, the drill used should have an included angle of A. 90° and turn at a low speed B. 118° and turn at a high speed. C. 140° and turn at a low speed.

C. 140° and turn at a low speed.

Which of these methods may be used to inspect fiberglass/honeycomb structures for entrapped water? 1. Acoustic emission monitoring. 2. X-ray. 3. Backlighting A. 1 and 2. B. 1 and 3. C. 2 and 3

C. 2 and 3.

Which fiber to resin (percent) ration for advanced composite wet lay-ups is generally considered the best for strength? A. 40:60. B. 50:50. C. 60:40

C. 60:40.

What is indicated by a black "smoky" residue streaming back from some of the rivets on an aircraft? A. The rivets were excessively work hardened during installation B. Exfoliation corrosion is occurring inside the structure C. Fretting corrosion is occurring between the rivets and the skin

C. Fretting corrosion is occurring between the rivets and the skin

If a new safety belt is to be installed in an aircraft, the belt must conform to the strength requirements in which document? A. STC 1282. B. FAR part 39. C. TSO C22.

C. TSO C22.

What is the purpose of refrigerating 2017 and 2024 aluminum allow rivets after heat treatment? A. to accelerate age hardening B. To relieve internal stresses C. To retard age hardening

C. To retard age hardening

Repairing advanced composites using materials and techniques traditionally used for fiberglass repairs is likely to result in A. restored strength and flexibility. B. improved wear resistance to the structure. C. an unairworthy repair.

C. an unairworthy repair.

If no scratches are visible after transparent plastic enclosure materials have been cleaned, their surfaces should be A. polished with rubbing compound applied with a damp cloth. B. buffed with a clean, soft, dry cloth. C. covered with a thin coat of wax.

C. covered with a thin coat of wax.

If an aircraft's transparent plastic enclosures exhibit fine cracks which may extend in a network over or under the surface or through the plastic, the plastic is said to be A. hazing. B. brinelling. C. crazing.

C. crazing.

Select the alternative which best describes the function of the flute section of a twist drill. A. prevents overheating of the drill point. B. forms the area where the drill bit attaches to the drill motor. C. forms the cutting edges of the drill point.

C. forms the cutting edges of the drill point.

Which statement is true regarding the inspection of a stressed skin metal wing assembly known to have been critically loaded? A. if rivets show no visible distortion, further investigation is unnecessary. B. if bearing failure has occurred, the rivet shanks will be joggled. C. if genuine rivet tipping has occurred, groups of consecutive rivet heads will be tipped in the same direction.

C. if genuine rivet tipping has occurred, groups of consecutive rivet heads will be tipped in the same direction.

The preferred way to make permanent repairs on composites is by A. bonding on metal or cured composite patches. B. riveting on metal or cured composite patches. C. laminating on new repair plies.

C. laminating on new repair plies.

Repairs or splices involving stringers on the lower surface of stressed skin metal wings are usually A. not permitted. B. permitted only if the damage does not exceed 6 inches in any direction. C. permitted but are normally more critical in reference to strength in tension than similar repairs to the upper surface.

C. permitted but are normally more critical in reference to strength in tension than similar repairs to the upper surface.

The Dzus turnlock fastener consists of a stud, grommet and receptacle. The stud diameter is measured in A. tenths of an inch. B. hundredths of an inch. C. sixteenths of an inch.

C. sixteenths of an inch.

The identifying marks on the heads of aluminum alloy rivets indicate the A. degree of dimensional and process control observed during manufacture B. head shape, shank size, material used, and specifications adhered to during manufacture C. specific alloy used in the manufacture of the rivets

C. specific alloy used in the manufacture of the rivets

When balsa wood is used to replace a damaged honeycomb core, the plug should be cut so that A. the grain is parallel to the skin. B. it is about 1/8 inch undersize to allow sufficient bonding material to be applied. C. the grain is perpendicular to the skin.

C. the grain is perpendicular to the skin.

One of the main advantages of Hi-Lok type fasteners over earlier generations is that A. they can be removed and reused again. B. the squeezed on collar installation provides a more secure, tighter fit. C. they can be installed with ordinary hand tools.

C. they can be installed with ordinary hand tools.

What is one of the determining factors which permits machine countersinking when flush riveting? A. thickness of the material and rivet diameter are the same. B. thickness of the material is less than the thickness of the rivet head. C. thickness of the material is greater than the thickness of the rivet head.

C. thickness of the material is greater than the thickness of the rivet head.

The general rule for finding the proper rivet diameter is A. three times the thickness of the materials to be joined. B. two times the rivet length. C. three times the thickness of the thickest sheet.

C. three times the thickness of the thickest sheet.

What is the purpose of a gusset or gusset plate used in the construction and repair of aircraft structures? A. to hold structural members in position temporarily until the permanent attachment has been completed. B. to provide access for inspection of structural attachments. C. to join and reinforce intersecting structural members.

C. to join and reinforce intersecting structural members.

What is the minimum spacing for a single row of aircraft rivets? A. two times the diameter of the rivet shank. B. three times the length of the rivet shank. C. three times the diameter of the rivet shank.

C. tree times the diameter of the rivet shank.

What reference tool is used to determine how the fiber is to be oriented for a particular ply of fabric? A. fill clock (or compass). B. bias clock (or compass). C. warp clock (or compass).

C. warp clock (or compass).

When necessary, what type of cutting fluid is usually acceptable for machining composite laminates? A. water soluble oil. B. water displacing oil. C. water only.

C. water only.

When making repairs to fiberglass, cleaning of the area to be repaired is essential for a good bond. The final cleaning should be made using A. MEK (methyl ethyl ketone). B. soap, water, and a scrub brush. C. a thixotropic agent.

A MEK (methyl ethyl ketone).

Which of the following are generally characteristic of aramid fiber (Kevlar) composites? 1. high tensile strength. 2. flexibility. 3. stiffness. 4. corrosive effect in contact with aluminum. 5. ability to conduct electricity. A. 1 and 2. B. 2, 3 and 4. C. 1, 3, and 5.

A. 1 and 2.

(Refer to Figure 1.) Which of the rivets shown will accurately fit the conical depression made by a 100° countersink? A. 1. B. 2. C. 3.

A. 1.

What should be the included angle of a twist drill from hard metals? A. 188° B. 100° C. 90°

A. 118°

The primary alloying agent of 2024-T36 is indicated by the number A. 2 B. 20 C. 24

A. 2

Which part of the 2017-T36 aluminum alloy designation indicates the primary alloying agent used in its manufacture? A. 2 B. 17 C. 20

A. 2

Which of the following, when added to wet resins, provide strength for the repair of damaged fastener holes in composite panels? 1. microballoons. 2. flox. 3. chopped fibers. A. 2 and 3. B. 1 and 3. C. 1, 2, and 3.

A. 2 and 3.

How many of the following are benefits of using microballoons when making repairs to laminated honeycomb panels? 1. Greater concentrations of resin in edges and corners. 2. Improved strength to weight ration. 3. Less density. 4. Lower stress concentrations. A. 2, 3, and 4. B. 1, 2, and 4. C. 1, 3, and 4

A. 2, 3, and 4.

How many MS20470 AD-4-6 rivets will be required to attach a 10 x 5 inch plate, using a single row of rivets, minimum edge distance, and 4D spacing? A. 56. B. 54. C. 52.

A. 56.

The classification for fiberglass reinforcement material that has high resistivity and is the most common is A. E. B. S. C. G.

A. E.

Which is an identifying characteristic of acrylic plastics? A. Zinc chloride will have no effect. B. Acrylic has a yellowish tint when viewed from the edge. C. Acetone will soften plastic, but will not change its color.

A. Zinc chloride will have no effect.

Which is correct concerning the use of a file? A. apply pressure on the forward stroke, only, except when filing very soft metals such as lead or aluminum. B. a smoother finish can be obtained by using a double cut file than by using a single-cut file. C. the terms "double cut" and "second cut" have the same meaning in reference to files.

A. apply pressure on the forward stroke, only, except when filing very soft metals such as lead or aluminum.

What is the material layer used within the vacuum bag pressure system to absorb excess resin during curing called? A. bleeder. B. breather. C. release.

A. bleeder.

The markings on the head of a Dzus fastener identify the A. body diameter, type of head, and length of the fastener. B. body type, head diameter, and type of material. C. manufacturer and type of material.

A. body diameter, type of head, and length of the fastener.

Shallow scratches in sheet metal may be repaired by A. burnishing. B. buffing. C. stop drilling.

A. burnishing.

Alloy 2117 rivets are heat treated A. by the manufacturer and do not require treatment before being driven. B. by the manufacturer but require reheat treatment before being driven. C. to a temperature of 910 to 930° and quenched in cold water.

A. by the manufacturer and do not require treatment before being driven.

Rivet gauge, or transverse pitch is the distance between the A. center of rivets in adjacent rows B. center of adjacent rivets in the same row C. head of rivets in the same row

A. center of rivets in adjacent rows

Most rivets used in aircraft construction have A. dimples B. smooth heads without markings C. a raised dot

A. dimples

Fiberglass laminate damage not exceeding the first layer or ply can be repaired by A. filling with a putty consisting of a compatible resin and clean, short glass fibers. B. sanding the damaged area until aerodynamic smoothness is obtained. C. trimming the rough edges and sealing with paint.

A. filling with a putty consisting of a compatible resin and clean, short glass fibers.

The coefficient of expansion of most plastic enclosure materials is A. greater than both steel and aluminum. B. greater than steel but less than aluminum. C. less than either steel or aluminum.

A. greater than both steel and aluminum.

Sandwich panels made of metal honeycomb construction are used on modern aircraft because this type of construction A. has a high strength to weight ration. B. may be repaired by gluing replacement skin to the inner core material with thermoplastic resin. C. is lighter than single sheet skin of the same strength and is more corrosion resistant.

A. has a high strength to weight ration.

The Dzus turnlock, fastener consists of a stud, grommet, and receptacle. The stud length is measured in A. hundredths of an inch. B. tenths of an inch. C. sixteenths of an inch.

A. hundredths of an inch.

Under certain conditions, type A rivets are not used because of thier A. low strength characteristics B. high alloy content C. tendency toward embrittlement when subjected to vibration

A. low strength characteristics

Fiberglass damage that extends completely through a laminated sandwich structure A. may be repaired. B. must be filled with resin to eliminate dangerous stress concentrations. C. may be filled with putty which is compatible with resin.

A. may be repaired.

Heat-treated rivets in the D and DD series that are not driven within the prescribed time after heat treatment or removal from refrigeration A. must be reheat treated before use B. must be discarded C. may be returned to refrigeration and used later without reheat treatment

A. must be reheat treated before use

A main difference between Lockbolt/Huckbolt tension and shear fasteners (other than application) is the A. number of locking collar grooves. B. shape of the head. C. method of installation.

A. number of locking collar grooves.

The shop head of a rivet should be A. one and one-half times the diameter of the rivet shank. B. one-half times the diameter of the rivet shank. C. one and one-half times the diameter of the manufactured head of the rivet.

A. one and one-half times the diameter of the rivet shank.

When an MS20470D rivet is installed, its full shear strength is obtained A. only after a period of age hardening B. by the cold working of the rivet metal in forming a shop head C. by heat treating just prior to being driven

A. only after a period of age hardening

Composite inspections conducted by means of acoustic emission monitoring A. pick up the "noise" of corrosion or other deterioration occurring. B. analyze ultrasonic signals transmitted into the parts being inspected. C. create sonogram pictures of the areas being inspected.

A. pick up the "noise" of corrosion or other deterioration occurring.

Hole filling fasteners (for example, MS20470 rivets) should not be used in composite structures primarily because of the A. possibility of causing delamination. B. increased possibility of fretting corrosion in the fastener. C. difficulty in forming a proper shop head.

A. possibility of causing delamination.

The length of time that a catalyzed resin will remain in a workable state is called the A. pot life. B. shelf life. C. service life.

A. pot life.

What precaution, if any should be taken to prevent corrosion inside a repaired metal honeycomb structure? A. prime the repair with a corrosion inhibitor and seal from the atmosphere. B. paint the outside area with several coats of exterior paint. C. none. honeycomb is usually made from a manmade or fibrous material which is not susceptible to corrosion.

A. prime the repair with a corrosion inhibitor and seal from the atmosphere.

Aircraft structural units, such as spars, engine supports, etc., which have been built up from sheet metal, are normally A. repairable, using approved methods B. repairable, except when subjected to compressive loads C. not repairable, but must be replaced when damaged or deteriorated

A. repairable, using approved methods

When straightening members made of 2024-T4, you should A. straighten cold and reinforce. B. straighten cold and anneal to remove stress. C. apply heat to the inside of the bend.

A. straighten cold and reinforce.

One method of inspecting a laminated fiberglass structure that has been subjected to damage is to A. strip the damaged area of all paint and shine a strong light through the structure. B. use dye-penetrant inspection procedures, exposing the entire damaged area to the penetrant solution. C. use an eddy current probe on both sides of the damaged area.

A. strip the damaged area or all paint and shine a strong light through the structure.

When repairing a small hole on a metal stressed skin, the major consideration in the design of the patch should be A. the shear strength of the riveted joint. B. to use rivet spacing similar to a seam in the skin. C. that the bond between the patch and the skin is sufficient to prevent dissimilar metal corrosion.

A. the shear strength of the riveted joint.

A category of plastic material that is capable of softening or flowing when reheated is described as a A. thermoplastic B. thermocure. C. thermoset.

A. thermoplastic.

What is the minimum edge distance for aircraft rivets? A. two times the diameter of the rivet shank. B. two times the diameter of the rivet head. C. three times the diameter of the rivet shank.

A. two times the diameter of the rivet shank.

Fiberglass laminate damage that extends completely through one facing and into the core A. cannot be repaired. B. requires the replacement of the damaged core and facing. C. can be repaired by using a typical metal facing patch.

B requires the replacement of the damaged core and facing.

Proper pre-preg composite lay-up curing is generally accomplished by 1. applying external heat. 2. room temperature exposure. 3. adding a catalyst or curing agent to the resin. 4. applying pressure. A. 2 and 3. B. 1 and 4. C. 1, 3, and 4.

B. 1, and 4.

A sheet metal repair is to be made using two pieces of 0.040-inch aluminum riveted together. All rivet holes are drilled for 3/32-inch rivets. The length of the rivets to be used will be A. 1.8 inch B. 1/4 inch C. 5/16 inch

B. 1/4 inch

The dimensions of an MS20430AD-4-8 rivet are A. 1/8 inch in diameter and 1/4 inch long B. 1/8 inch in diameter and 1/2 inch long C. 4/16 in diameter and 8/32 inch long

B. 1/8 inch in diameter and 1/2 inch long