Wood Structures Flashcards
In cases of elongated boltholes in a wood spar or cracks in the vicinity of boltholes,
a new section of spar should be spliced in or the spar replaced entirely.
A faint line running across the grain of a wood spar generally indicates
Compression failure
The I-beam wooden spar is routed to
Reduce weight
The strength of a well designed and properly prepared wood splice joint is provided by the
Glue
Laminated wood is sometimes used in the construction of highly stressed aircraft components. This wood can be identified by its
Parallel grain construction
Laminated wood spars may be substituted for solid rectangular wood spars
If the same quality of wood is used in both
Where is information found concerning acceptable species substitutions for wood materials used in aircraft repair?
AC 43.13-1B
When patching a plywood skin, abrupt changes in cross sectional areas which will develop dangerous stress concentration should be avoided by using
circular or elliptical patches
Which statement about wood decay is correct?
Decay is not acceptable in any form or amount.
Which of the following conditions will determine acceptance of wood with mineral streaks?
Careful inspection fails to reveal any decay.
Glue deterioration in wood aircraft structure is indicated
when a joint has separated and the glue surface shows only the imprint of the wood with no wood fibers clinging to the glue.
Pin knot clusters are permitted in wood aircraft structure provided
they produce a small effect on grain direction.
Compression failures in wood aircraft structures are characterized by buckling of the fibers that appear as streaks on the surface
At right angles to the grain
How many fabric thicknesses will be found in a French fell seam?
Four
The determining factor(s) for the selection of the correct weight of textile fabric to be used in covering any type of aircraft is the
speed of the aircraft and the maximum wing loading.
The strength classification of fabrics used in aircraft covering is based on
Tensile Strength
When testing the strength of Grade A cotton fabric covering an aircraft that requires only intermediate grade, the minimum acceptable strength the fabric must have is
70 percent of the original strength for intermediate fabric.
When and how is finishing tape applied on a fabric covered aircraft
Doped on after the first or second coat of dope.
Finishing tape (surface tape) is used for what purpose?
To provide additional wear resistance over the edges of fabric forming structures.
The best method of repair for a fabric covered surface which has an L shaped tear, each leg of which is approximately 14 inches long, is to
sew with a baseball stitch from the center of the tear out toward the extremity of each leg and then dope on a patch.
Moisture, mildew, chemicals, and acids have no effect on
Glass fabric
correct use for acetone is to
Remove grease from fabric
Which of the following is a hazard associated with sanding on fabric covered surfaces during the finishing process?
Static electricity build up
Fabric rejuvenator
restores the condition of dope coatings.
What is used to slow the drying time of some finishes and to prevent blush?
Retarder
Aluminum-pigment in dope is used primarily to
Exclude sunlight from the fabric
Fungicidal dopes are used in aircraft finishing as the
first coat to prevent fabric rotting and are applied thin enough to saturate the fabric.
