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53 Cards in this Set
- Front
- Back
- 3rd side (hint)
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For maximum strength of a formed sheet metal fitting, should the bend be made along or across the grain of the metal? |
Across the grain |
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What determines the minimum bend radius that can be used when forming a sheet metal structure fitting? |
Alloy type, thickness, and the hardness of the metal. |
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What is meant by the neutral axis in sheet metal? |
The plane within the metal that is neither stretched nor shrinked when the metal is bent. |
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What is a mold line in the development of a flat pattern for a formed metal part? |
An extension of the flat sides beyond the radius. |
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What is a bend tangent line? |
A line in a flat pattern layout at which the bend starts. |
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What is meant by setback? |
The distance the jaws of a brake must be set back from the mold line to form a bend. |
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What is meant by bend allowance? |
The actual amount of metal in a band. It is the distance between the bend tangent lines in a flat pattern layout. |
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What is a sight line? |
A line drawn on a flat pattern layout within the bend allowance that is one band radius from the bend tangent line. The sight line is directly below the nose of the radius bar on the brake, so the bend will start at the bend tangent line. |
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What type of device is a cleco fastener? |
A patented fastener that is inserted in a rivet hole and used to hold two pieces of sheet metal together until they can be reverted. |
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What is the main function of the throatless shears in an aircraft sheet metal shop? |
Used to cut mild carbon steel up to 10 gage, and stainless steel up to 12 gage. They can be used to cut irregular curves in the metal. |
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What kind of metal forming is done by a slip roll former? |
Simple curves with a large radius. |
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What kind of metal forming is done by bumping? |
Compound curves in sheet metal. |
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When forming a curved angle what must be done to the flanges? |
Stretch the flanges for a convex curve and shrunk for a concave curve. |
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When hand forming a piece of sheet metal that has a concave curve, should be forming be started in the center of the curve or at its edges? |
Start at the edges and work towards the center. |
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What is meant by a joggle in a piece of sheet metal? |
Small offset near the edge of a piece of sheet metal, that allows the sheet to overlap another piece of metal. |
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What is the minimum edge distance allowed when installing rivets in a piece of aircraft sheet metal structure? |
2 times the diameter of the river shank. |
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What is the recommended transverse pitch to use when making a riveted two row splice on a piece of sheet metal? |
3/4 of the distance between the rivets in the rows |
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Why should aluminum alloy rivets be driven with a few blows as is practical? |
Excessive hammering will work harden the rivets and make them difficult to drive. |
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What determines whether a piece of sheet metal should be dimpled or countersunk when installing flush rivets? |
The thickness of the sheet. |
Countersinking should be used only for thickness of a sheet greater than the thickness of the rivet head. |
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What type of metal should be hot- dimpled? |
77075-T6, 2024-T81 aluminum alloys, and magnesium alloys. |
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What should be done to protect a riveted joint between aluminum alloys and magnesium alloy from corrosion? |
Coat the faying surface with a corrosion inhibiting primer, deep the rivets in the primer and drive them while the primer is wet. |
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Which stringer attached to a wing skin would require the greatest number of rivets for a splice? |
The stringer and the lower surface. |
Since pressure is higher at the bottom of the aircraft wing. |
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What type of rivet may be used to replace a round head rivet in an aircraft structure? |
A universal head rivet. |
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How long should a rivet be to join two pieces of sheet metal? |
The combined thickness of the metal sheets being joined, plus one and a half times the rivet shank diameter. |
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Should a rivet joint fail in shaer or in bearing? |
In shear, so the rivet fails before the rivet holes tear. |
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What is the purpose of a beehive spring on a rivet gun? |
It holds the rivet set in the gun and allows the gun to vibrate the set. |
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How can water entrapped in a honeycomb structure be detected? |
By use of radiographic inspection. |
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What effects can entrapped moisture have on a metal honeycomb structure? |
Causes corrosion. |
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What is the simplest way to detect delamination in a composite structure? |
Tap the surface with the age of a coin. Clear sound indicates the material is in a good state, a dull thud sound indicates delamination. |
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What type of non-destructive inspection is suitable for detecting internal damage in honeycomb material? |
Ultrasonic inspection. |
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What kind of repair can be made to a small damage of a core material and one face sheet of a piece of aluminum alloy honeycomb structure? |
A potted compound repair. |
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What special precautions must be taken when repairing a radome? |
Nothing should be done that affects its electrical transparency or its aerodynamic strength. |
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How do you grind the point of a twist drill that is to be used for drilling transparent acrylic material? |
The cutting edge should be dubbed off to zero rake angle, and the included angle of the tip should be ground to 140° |
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What is a WARP clock in a structural repair manual? |
An alignment indicator to show the orientation of the plies of a composite material. The ply direction is shown in relation to the reference direction. |
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What are two advantages of laminated construction over Riveted sheet metal? |
Lightweight and rigidity |
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What are two popular types of core materials used in a laminated structure? |
Foam and honeycomb. |
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What are two popular types of metrix material used on laminated structure? |
Polyester and epoxy resins. |
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What are two parts of a polyester matrix material? |
Resin and catalyst |
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What are two parts of an epoxy matrix material? |
Resin and hardener. |
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What are the two types of resins used in aircraft construction? |
Thermoplastic and thermosetting. |
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What are three materials that may be used to reinforce the matrix material for aircraft structure? |
Fiberglass Kevlar, and graphite. |
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What is necessary to cure thermosetting resin? |
Heat. |
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What is meant by ribbon direction of a honeycomb material? |
The direction and a piece of honeycomb material that is parallel to the length of the strips of material that make up the core. |
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What are two types of repair to a damaged honeycomb core composite material? |
Room temperature cure repair and hot Bond repair. |
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What is meant by the shelf life of a material? |
The normal length of time a material can be expected to keep its usable characteristics if it's stored and not used. |
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What is meant by the pot life of a resin? |
The length of time a resin will remain workable after the catalyst has been added. |
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What document lists the safety hazards associated with a resin used in composite structures? |
The material safety data sheet for that resin. |
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Of what class of resins are aircraft windows and windshields made? |
Thermoplastic. |
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What type of transparent plastic material is used for most aircraft windshields? |
Acrylic plastic. |
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How should sheets of transparent plastic material be stored? |
Leave the protective paper on the material and store in a tilted position, approximately 10° from the vertical. |
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How tight should the screws be tightened when installing an acrylic windshield in a channel? |
Tighten to a firm fit and back it off one full turn. |
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What is meant by crazing of a transparent plastic material? |
Tiny hair like cracks that may not extend all of the way to the surface, caused by stresses or chemical fumes. |
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What type of material is used to remove surface damage to a piece of acrylic resin? |
Micro-mesh abrasive sheets |
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