Jeppesen Oral- Chapter 3 ( Wood, Composite, Transparent Structures) Flashcards
What are the three forms of wood commonly used in aircraft construction?
Solid, laminated and plywood
What type of wood should be used when splicing or reinforcing plywood webs?
The same type of plywood as originally used
Name at least four different types of defects found in wood.
Knots, checks, splits, pitch pockets, cross grain, decay, dry rot
Can a section of wood containing a hard knot be used?
Yes within limits
What type of glue may have been used in older wooden aircraft construction that requires careful inspection to detect deterioration?
Casein glue
What are the three types of glues used in modern aircraft construction and repair?
Resorcinol glue, phenol-formaldehyde, epoxy resin
Is compression acceptable for structural repair?
`No
Why should the various pieces of wood being joined be kept in the same room for at least 24 hours prior to joining?
To allow moisture content to equalize, minimizes dimensional changes to the wood
Why is it important to consider the open-assembly time when gluing wooden structures?
If maximum is exceeded, the joint may fail
Why is it important to apply the proper clamping pressure to a glue joint?
Clamping forces air out of the joint, brings the wood together evenly
Describe some of the methods used to apply pressure to glue joints
Clamps, nailing strips, power presses, brads, nail, and small screws
What minimum curing temperature should be observed when joining wood with various adhesives?
70 degrees F or recommended by manufacturer
When inspecting wood structures, why might it be important to consider stains and discolored areas?
Usually accompany decay
Describe the acceptable methods used to repair elongated bolt holes found in wooden wing spar.
Remove section containing the elognated hole and splice in a new section or replace entire spare
What type of joint is used to splice a solid or rectangular wood spar?
A scarf joint