Wood Structures

Question 1

In cases of elongated boltholes in a wood spar or cracks in the vicinity of boltholes,

Answer 1

a new section of spar should be spliced in or the spar replaced entirely.

Question 2

A faint line running across the grain of a wood spar generally indicates

Answer 2

Compression failure

Question 3

The I-beam wooden spar is routed to

Answer 3

Reduce weight

Question 4

The strength of a well designed and properly prepared wood splice joint is provided by the

Answer 4

Glue

Question 5

Laminated wood is sometimes used in the construction of highly stressed aircraft components. This wood can be identified by its

Answer 5

Parallel grain construction

Question 6

Laminated wood spars may be substituted for solid rectangular wood spars

Answer 6

If the same quality of wood is used in both

Question 7

Where is information found concerning acceptable species substitutions for wood materials used in aircraft repair?

Answer 7

AC 43.13-1B

Question 8

When patching a plywood skin, abrupt changes in cross sectional areas which will develop dangerous stress concentration should be avoided by using

Answer 8

circular or elliptical patches

Question 9

Which statement about wood decay is correct?

Answer 9

Decay is not acceptable in any form or amount.

Question 10

Which of the following conditions will determine acceptance of wood with mineral streaks?

Answer 10

Careful inspection fails to reveal any decay.

Question 11

Glue deterioration in wood aircraft structure is indicated

Answer 11

when a joint has separated and the glue surface shows only the imprint of the wood with no wood fibers clinging to the glue.

Question 12

Pin knot clusters are permitted in wood aircraft structure provided

Answer 12

they produce a small effect on grain direction.

Question 13

Compression failures in wood aircraft structures are characterized by buckling of the fibers that appear as streaks on the surface

Answer 13

At right angles to the grain

Question 14

How many fabric thicknesses will be found in a French fell seam?

Answer 14

Four

Question 15

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

Answer 15

speed of the aircraft and the maximum wing loading.

Question 16

The strength classification of fabrics used in aircraft covering is based on

Answer 16

Tensile Strength

Question 17

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

Answer 17

70 percent of the original strength for intermediate fabric.

Question 18

When and how is finishing tape applied on a fabric covered aircraft

Answer 18

Doped on after the first or second coat of dope.

Question 19

Finishing tape (surface tape) is used for what purpose?

Answer 19

To provide additional wear resistance over the edges of fabric forming structures.

Question 20

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

Answer 20

sew with a baseball stitch from the center of the tear out toward the extremity of each leg and then dope on a patch.

Question 21

Moisture, mildew, chemicals, and acids have no effect on

Answer 21

Glass fabric

Question 22

correct use for acetone is to

Answer 22

Remove grease from fabric

Question 23

Which of the following is a hazard associated with sanding on fabric covered surfaces during the finishing process?

Answer 23

Static electricity build up

Question 24

Fabric rejuvenator

Answer 24

restores the condition of dope coatings.

Question 25

What is used to slow the drying time of some finishes and to prevent blush?

Answer 25

Retarder

Question 26

Aluminum-pigment in dope is used primarily to

Answer 26

Exclude sunlight from the fabric

Question 27

Fungicidal dopes are used in aircraft finishing as the

Answer 27

first coat to prevent fabric rotting and are applied thin enough to saturate the fabric.