Sheetmetal And Nonmetallic Structures Flashcards
A well designed rivet joint will be subject the rivets to
Shear loads
The main difference between lockbolt and huckbolt tension and shear fasteners, other than their application, is in the
Number of locking collar grooves
Alloy 2117 rivets are heat treated
By the manufacturer and do not require heat treatment before being driven
The general rule for finding the proper rivet diameter is?
Three times, the thickness of the thickest sheet being riveted
The shop head rivet should be
One and one half times the diameter of the rivet shank
One of the main advantages of HI-lok type fasteners over earlier generations is that
They can be installed with ordinary hand tools
Which of the following is one advantage hi-lok fasteners
Inability to be overtorqued
The markings on the head of a dzus fastener identify the
Body diameter, type of head, and length of the fastener
The Dzus turn lock fastener consists of a stud and grommet receptacle, the stud is measured in
Hundredths of an inch
The dzus turn lock fastener consists of a stud grommet and a receptacle
The stud diameter is measured in
Sixteenths of an inch
Threaded rivets [rivnuts] are commonly used to
Attach parts or components with screws to a sheet of metal
The instalation of a cherry max and Olympic-lok rivets is accomplished by utilizing
A pulling tool
Hole filling fasteners (for 3xaple MS20470 rivets) should not be used in composite structures primarily because of the
Possibility of causing delamination
Metal fasteners, used with carbon/graphite composite structures
Must be constructed of a material such as titanium or corrosion resistant steel
Sandwich panels made of honeycomb construction are used on aircraft because this type of construction
Saves weights while not compromising strength
Which of these methods may be used to inspect fiberglass/honeycomb structures for entrapped water
Xray/and blacklighting
When balsa wood is used is used to replace a damaged honeycomb core, the plug should be cut, so that
The grain is perpendicular to the skin
When repairing puncture type damage to a metal faced laminated honeycomb panel, the edges of the doubler should be tapered
100 times the thickness of the metal
One of the best ways to assure that a properly prepared patch of matrix resin has been achieved is to
Have a mixed enough for a test sample
How does acoustic emissions testing detect defects in composite materials
By picking up the noise of any deterioration that may be present
When conducting a tap test on a composite panel, which of the following would indicate delamination
Dull thud
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
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
When inspecting a composite panel using the ring test/tapping method, a dull thud may indicate
Separation of the laminates
Which of the following are benefits of using micro-balloons when making repairs to laminated honeycomb panels
Improved strength to weight ratio, less density and lower stress concentration
The length of time that a catalyzed resin will remain in a workable state is called the
Pot life
A category of plastic material that is capable of softening or flowing when reheated is described as a
Thermoplastic
The classification, for high tensile strength fiber glass used in aircraft structures is
S-glass
Which is an identifying characteristic of acrylic plastic?
Zinc chloride will have no effect
Superficial scars, scratches, surface abrasion, or rain erosion on fiver glass laminates can generally be repaired by applying
One or more coats of suitable resin (at room temperature catalyzed) to the surface
The classification for fiberglass reinforcement material that has a resistivity and is the most common is
E-glass
A potted compound repair on honeycomb can usually be made on damages less than
1 inch in diameter
Composite fabric material is considered to be the strongest in what direction?
Warp
What references tool is used to determine how the fiber is oriented for a particular ply of fabric
Warp clock(or compass)
The strength and stiffness of a properly constructed composite buildup depend primarily on
The orientation of the plies to the load direction
Which fiber to resin (percent) ratio for advanced composite wet layups is generally considered the best for strength
60:40 fiver to resin ratio
What is the material layer used within the vacuum bag pressure system to absorb excess resin during curing called
Bleeder
Proper prepreg composite layup curing is generally accomplished by
Applying external heat and pressure
When repairing large, flat surfaces with polyester resin, warping of the surface is likely to occur. One method of reducing the amount of warpage is to
Use short strips of fiberglass in the bonded repair
When making repairs to fiberglass, cleaning the area to be repaired is essential for a good bond. The final cleaning should be made using
MEK/methyl ethyl ketone
When necessary, what type of cutting fluid is usually acceptable for machining composites laminates
Water only
Fiberglass laminates
Filling with a putty consisting of a compatible resin and clean short glass fibers
Fiberglass damage that extends completely through a laminated sandwich structure
May be repaired
Fiberglass laminate damage that extends completely through one facing and into the core
Requires the replacement of the damaged core and facing
Repairing advanced composites, using materials and techniques traditionally used for fiberglass repairs, is likely to result in
An unairworthy repair
The preferred way to make permanent repairs on composites is by
Laminating on new repair plies
Which of the following is added to wet resins provide strength for the repair of damaged fastener holes in composite panels
Flox and chopped fibers
The part of a replacement honeycomb core that must line up with the adjacent original is the
Ribbon Direction
Which of the following are generally characteristic of aramid fiber (kevlar) composites
High tensile strength and flexibility
Which of the following are generally characteristics of carbon/graphite fiber composites?
Stiffness, high compressive strength, and corrosive effects in contact with aluminum
If an aircraft transparent plastic enclosure exhibits fine cracks, which may extend in a network over or under the surface or through the plastic, the plastic is said to be
Crazing
When installing transparent plastic enclosures that are retained by bolts extending through the plastic material and self-locking nuts the nuts should be
Tighned to a firm fit, then backed off one full turn
If a new safety belt is to be installed in an aircraft, the belt must conform to the strength requirements in which document
TSO C22
Which is considered good practice concerning the installation of acrylic plastics
When rivets are used adequate spacer or other satisfactory means to prevent excessive tightening
The coefficient of most plastic enclosed materials is
Greater than both steel and aluminum
If no scratches are visible after transparent plastic enclosure, mayerials have been cleaned their surface should be
Covered on a thin coat of wax
Cabin upholstery materials installed in current standard category airplanes must
Be at least flame resistant
What is the most common method of cementing transparent plastics
Soak method
What type of bit should be used to drill holes in plexiglass
A specially modified twist drill
Which of the following drill bit types work best when drilling an aramid fiber (kevlar) composite laminates
Carbon W-point
What is the purpose of a gusset(plate) used in the construction and repair of aircraft structures
To join and reinforce intersecting structural members
Select the alternative that best describes the function of the flute section of a twist drill bit
Forms of cutting edges of the drill point
How many MS204070 AD-4-6 rivets will be required to attach a plate using a single row of rivets, minimum edge distance, and 4D spacing
56 rivets
1/8 in diameter
On a semi-monocoque fuselage, the skin is reinforced by longitudinal structural members called
Longerons and stringers
Shallow scratches in sheet metal may be repaired by
Burnishing
What could be the included angle of twist drill for soft metals
90*
When comparing the machining technique for stainless steel material to those for aluminum alloy sheets, it is normally considered good practice to drill the stainless steel at
Lower speed with more pressure applied to the drill
A single lap sheeplt splice is to be used to repair a section of damaged aluminum skin. If a double row of 1/8 in rivets is used, the minimum allowable overlap will be
13/16 inch
What is the minimum edge distance allowed for aluminum alloy single lap sheet splices containing a single row of rivets as compared to a joint with multiple rows all rivets being equal in diameter
The minimum edge distance for the single row is equal to that for the multiple row
This statement is true regarding the inspection of a stressed skin metal Qing assembly known to have been critically loaded
If Ginuwine rivet tipping has occurred, groups of consecutive rivets will be tipped in the same direction
What is the minimum edge distance for aircraft rivets?
Two times the diameter of the rivet shank
When drilling a stainless steel, the drill used should have an included angle of
140* and turn at a low speed
What is the minimum spacing for a single row of aircraft rivets
Three times the diameter of the rivet shank
Which is the correct concerning the use of a file?
Apply pressure on the forward stroke, only, except when filing very soft metals such as lead or aluminum
What is one of the determining factors that permits machine countersinking when flush riveting
The thickness of the material is greater than the thickness of the rivet head, which gives enough strength to countersink
Qhwn repairing a small hole on a metal stressed skin the major consideration is the design of the patch should be?
The shear strength of the riveted joints
Which procedure is correct when utilizing a reamer to finish a drilled hole to the correct size
Turn the reamer only in the cutting direction
Repairing or splices involving stringers on the lower surface of stressed skin metal wings are usually
Permitted but are normally more critical on reference to strength in tension that similar repairs to the upper surface
When straightening members of 2024-T4 you should
Straightening cold and reinforce
Clad aluminum alloys are used in aircraft because they
Have surface layers of pure aluminum/alloy bonded to the core material to inhibit corrosion
Which statement is true regarding a cantilever wing
No external bracing is needed
Aircraft structural units such as spars engine supports,betc. Which have been built up from sheet metal are normally
Repairable, using approved methods
A factor that determines the minimum space between rivets is the
Diameter of the rivets being used
What should be the included angle of a twist drill for hard metal?
118*..
Parts fabricated from alclad 2024-T3 aluminum sheet stock must have all
Scratches kinks tool marks nicks, etc
Held to a minimum!!!
The monocoque fuselage relies largely on the strength of
The skin or covering of the plane/heli
Which parts of the semi-monocoque fuselage prevent tension from bending the fuselage?
Longerons and stringers
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