ESTRUCTURAS COMPUESTAS

If registration numbers are to be applied to an aircraft with a letter height of 12 inches, what is the minimum space required for the registration mark N1683C? Note: 2/3 x height = character width. 1/6 x height = width for 1. 1/4 x 2/3 height = spacing. 1/6 x height = stroke or line width. 52 inches. 48 inches. 57 inches.

If masking tape is applied to an aircraft such as for trim spraying, and is left on for several days and/or exposed to heat, it is likely that the tape will. not seal out the finishing material if the delay or heating occurs before spraying. be weakened in its ability to adhere to the surface. cure to the finish and be very difficult to remove.

What is used to slow the drying time of some finishes and to prevent blush?. Reducer. Retarder. Rejuvenator.

Which type of coating typically includes phosphoric acid as one of its components at the time of application?. Wash primer. Epoxy primer. Zinc chromate primer.

Which properly applied finish topcoat is the most durable and chemical resistant?. Synthetic enamel. Acrylic lacquer. Polyurethane.

Aluminum-pigment in dope is used primarily to. provide a silver color. aid in sealing out moisture from the fabric. reflect ultraviolet from the fabric.

A correct use for acetone is to. thin zinc chromate primer. remove grease from fabric. thin dope.

Which of the following is a hazard associated with sanding on fabric covered surfaces during the finishing process?. Overheating of the fabric/finish, especially with the use of power tools. Static electricity buildup. Embedding of particles in the finish.

What is likely to occur if unhydrated wash primer is applied to unpainted aluminum and then about 30 to 40 minutes later a finish topcoat, when the humidity is low?. Corrosion. A glossy, blush-free finish. A dull finish due to the topcoat 'sinking in' to primer that is still too soft.

Fungicidal dopes are used in aircraft finishing as the. first, full-bodied, brushed-on coat to prevent fungus damage. first coat to prevent fabric rotting and are applied thin enough to saturate the fabric. final, full-bodied, brushed-on coat to reduce blushing.

Before applying a protective coating to any unpainted clean aluminum, you should. wipe the surface with avgas or kerosene. remove any conversion coating film. avoid touching the surface with bare hands.

What is likely to occur if hydrated wash primer is applied to unpainted aluminum and then about 30 to 40 minutes later a finish topcoat, when the humidity is low?. Corrosion. A glossy, blush-free finish. A dull finish due to the topcoat 'sinking in' to primer that is still too soft.

What is the usual cause of runs and sags in aircraft finishes?. Too much material applied in one coat. Material is being applied too fast. Low atmospheric humidity.

Which defect in aircraft finishes may be caused by adverse humidity, drafts, or sudden changes in temperature?. Orange peel. Blushing. Pinholes.

Which statement is true regarding paint system compatibility?. Old-type zinc chromate primer may not be used directly for touchup of bare metal surfaces. Acrylic nitrocellulose lacquers may be used over old nitrocellulose finishes. Old wash primer coats may be overcoated directly with epoxy finishes.

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

How does acoustic emission testing detect defects in composite materials?. By picking up the 'noise' of any deterioration that may be present. By analyzing ultrasonic signals transmitted into the parts being inspected. By creating sonogram pictures of the areas being inspected.

What precaution, if any, should be taken to prevent corrosion inside a repaired metal honeycomb structure?. Prime the repair with a corrosion inhibitor and seal from the atmosphere. Paint the outside area with several coats of exterior paint. None. Honeycomb is usually made from a man-made or fibrous material which is not susceptible to corrosion.

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

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

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 ratio. 3. Less density 4. Lower stress concentrations. 2, 3, and 4. 1, 2, and 4. All of the above.

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

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

The classification for high tensile strength fiberglass used in aircraft structures is. E-glass. S-glass. G-glass.

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

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

The classification for fiberglass reinforcement material that has high resistivity and is the most common is. E-glass. S-glass. G-glass.

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

Composite fabric material is considered to be the strongest in what direction?. Fill. Warp. Bias.

What reference tool is used to determine how the fiber is to be oriented for a particular ply of fabric?. Fill clock (or compass). Bias clock (or compass). Warp clock (or compass).

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

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

What is the material layer used within the vacuum bag pressure system to absorb excess resin during curing called?. Bleeder. Breather. Release.

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. 2 and 3. 1 and 4. 1, 3, and 4.

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. add an extra amount of catalyst to the resin. use short strips of fiberglass in the bonded repair. use less catalyst than normal so the repair will be more flexible.

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. MEK (methyl ethyl ketone). soap, water, and a scrub brush. a thixotropic agent.

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

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

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

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

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

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

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. 2 and 3. 1 and 3. 1, 2, and 3.

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

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. 1 and 2. 2, 3, and 4. 1, 3, and 5.

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. 1 and 3. 2, 3, and 4. 1, 3, and 5.

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. hazing. brinelling. crazing.

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

If a new safety belt is to be installed in an aircraft, the belt must conform to the strength requirements in which document?. STC 1282. 14 CFR Part 39. TSO C22.

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

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

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

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

What is the most common method of cementing transparent plastics?. Heat method. Soak method. Bevel method.

What type of bit should be used to drill holes in Plexiglas?. A standard twist drill. A specially modified twist drill. A dulled twist drill.

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