- What is the grip length of a rivet?
Combined thickness of the materials to be joined
- Where are special rivets, such as Huck or Cherry Lock rivets used?
both sides of structure are impossible to acess or limited space for bucking bar
- What is bonded honeycomb construction?
Laminar structure , bonded on both sides of core consisting of open 6 sided cell with dissimilar materials, increases the strength, reducing weight
- What type of materials are used in honeycomb construction
Stainless steel, titanium, magnesium, plywood, resin impregnated paper, e glass, nylon
- Where are sandwich construction assemblies used?
Bulkheads, control surfaces, fuselage panels, wing panels, randomness, empennage skins
- What procedures should be used to prevent damage to the hole when drilling though plexiglass?
Backed with wood, drill slow, modified drill bit 60 degree tip angle
- What calculations must be made when bending sheet metal?
Setback & bend allowance
- What factors are used to determine setback?
Radius of the bend & thickness of material
Setback = Radius+Thickness
- When bending sheet metel, how should the grain be in relation to the bend?
Grain should be perpendicular to the bend
- What is a bend tangent line?
Line which metal starts to bend
- What is a joggle?
Offset near the edge of a sheet of metal to allow clearance for a sheet or clearance
- What are several methods used in forming sheet metal?
folding, bumping, crimping, shrinking, & stretching
- What kind of metal forming is done by bumping?
Compound curves
- What is crazing and how does it occur?
Hairline cracks in surface of plastic. Caused by heat damage and excessive stress
- Briefly describe the anodizing process and what purpose it serves?
Aluminum alloys placed in electrolyte bath
Creates thin film of hydroxide to form
Anodized coating provide resistance to corrosion & bond for paint
- What are the proper dimensions for the shop head of a rivet?
After bucking
1.5x diameter in width
.5x diameter in height
- When inspecting plexiglass, what should you look for?
Crazing & discoloration
- What causes honeycomb structure to delaminate?
Moisture
- What are the acceptable repair, methods for bonded honeycomb structure that has been damaged?
Potted repair
Laminated glass fabric cloth overlay
- What size drill should be used for the common shank rivet diameter of 3/32inch,4/32 inch, & 5/32
3/32 use #40
4/32 use #30
5/32 use #21
- What is used for hole filling in bonded honeycomb repair?
Potting compund
- What is a lightening hole?
Holes cut into metal to increase strength and reduce weight
- What special precautions should be observed when repairing a radome?
Must retain strength & electrical transparency
- What is a warp line?
Highlighted strand in fabric used for ply orientation
- What does “pot life” mean?
Length of time resin is workable after mixed
- What is a Barcol hardness tester?
Device that pushes into material to measure if its cured or not
- What is done to honeycomb before repairing?
Removed damaged area
Either replace with potting compound or install honeycomb replacement plug
- What is the difference between thermoplastics & thermosetting plastics?
Thermoplastics can be remelted
Thermosetting cannot
