Sheet Metal and Non-metallic Structures Flashcards
What is done with the rivet head stem when a self plugging rivet is installed?
It is pulled until it is broken off, then trimmed flush with the rivet
Describe the correct dimensions on a properly formed rivet head.
1/2 Diameter tall, 1 1/2 Diameter wide
Give an example of a self plugging mechanical lock rivet.
CherryLOCK, CherryMAX, OlympicLOK, HuckLock
What is a bonded honeycomb construction?
Two relatively thin, parallel face sheets bonded together and separated by a relatively thick, lightweight core
Name two core materials used in special applications of bonded honeycomb construction.
Kraft paper, thermoplastics
Name two causes of delamination or debond of a honeycomb construction.
Matrix cracks
High or low energy impacts
Liquid ingestion
What is done with the damaged area in bonded honeycomb?
The damaged area must be removed
What is a potting compound repair used for in bonded honeycomb?
Hole filling
What will cause crazing in transparent plastic panels/ windshields?
Stress, improper handling, and harmful cleaning solvents
What should be done to twist drills that are to be used for drilling completely through plexiglass?
The drill must be free from nicks and burrs that would affect the surface finish. Grind the drill with an included angle of 150°. The rake angle should be zero in order to scrape, and not cut.
What calculations must be made when bending sheet metal?
Bend allowance and setback
What must be done when two bends intersect?
Relief holes must be drilled at the intersection
What methods are used in forming metals?
Bending
Bumping
Crimping
Folding
Stretching
Shrinking
How do you determine the total length of a solid rivet for installation?
Grip length plus 1-1/2 times the shank diameter
What factors are used to determine setback?
Material thickness and the bend radius
What is the purpose of lightening holes cut in rib sections?
To reduce weight and improve rigidity
What is joggle?
It is the offset formed on a part to allow clearance for a sheet or another mating part
How do you determine the proper materials used for a repair of an all metal aircraft?
Use the same type and thickness as the material in the original structure
What is the edge distance and spacing for single row of protruding head rivets?
ED - Two times the diameter
Spacing - Three times the diameter
Describe the rivet head markings for A, B, D, AD, DD rivets.
A- Plain
B- Cross
D- Raised Dot
AD- Dimple
DD- Double Dash
Describe the criteria for replacement of a 2024 rivet with a 2117 rivet for general repairs.
For 5/32 or less diameter, use the next larger size rivet, assuming spacing and ED meet minimum requirements.
