Aircraft Fabric Covering

Question 1

Aircraft covering fabrics are made of materials from what two sources?

Answer 1

Organic materials and synthetic materials

Question 2

How would you determine the strength requirements for fabric used to re-cover an aircraft?

Answer 2

The fabric must be of at least the quality and strength of the fabric by the original manufacturer

Question 3

What two types of organic fibers are used for covering aircraft?

Answer 3

Cotton and linen

Question 4

What is meant by warp, weft, and bias?

Answer 4

Warp is the direction along the length of a fabric, weft is the direction across the fabric at right angles to the warp, and bias is a direction at 45 degree angle to the warp and weft

Question 5

What is the purpose of the selvage edge on a roll of fabric?

Answer 5

It prevents the fabric from unraveling

Question 6

What identification marking is found on the selvage edge, and in which direction is the warp applied?

Answer 6

The FAA-PMA stamp is found on the selvage edge and the warp is applied parallel to the line of flight

Question 7

How are the fabric type and strength requirements determined for fabric-covered aircraft?

Answer 7

The original manufacturer determines the fabric type , and the strength requirements are a function of the never-exceed speed and wing loading

Question 8

What types of synthetic fibers are used for covering aircraft?

Answer 8

Fiberglass and heat-shrinkable polyester fibers

Question 9

Which of the several types of fabric is unaffected by moisture and mildew?

Answer 9

Fiberglass

Question 10

What is the function or purpose of reinforcing tape?

Answer 10

Reinforcing tape is used between the fabric and the rib stitching to prevent the lacing cord from cutting through the fabric

Question 11

Where would you use surface tape?

Answer 11

Over rib stitching and sewed seams, over lapped edges, around corners, and along leading and trailing edges

Question 12

How should the edges of drainage, inspection, and ventilation holes be reinforced?

Answer 12

With plastic, aluminum, or brass grommets

Question 13

What are the principle methods used to test the condition of fabric?

Answer 13

Punch testers such as the Maule or Seybolt tester, and laboratory pull-testing

Question 14

Fabric is considered unairworthy when it has deteriorated to what percentage of its original strength?

Answer 14

Less than 70%

Question 15

How should a structure that will be covered with doped fabric be prepared following inspection and prior to covering?

Answer 15

Treat it with a protective coating of paint or varnish as appropriate

Question 16

What is the principle advantage of the envelope method for covering wings?

Answer 16

Almost all the seams are machine-sewed by the envelope supplier

Question 17

What is a Tie-off knot?

Answer 17

A standard, modified seine knot used on all stitches except the starting stitch

Question 18

Name three common types of machine-sewed seams?

Answer 18

Plain overlap, folded-fell, and french-fell

Question 19

Where are anti-tear strips used?

Answer 19

Under wing rib stitching when the never-exceed speed is greater than 250 MPH

Question 20

How would you determine the correct spacing for rib stitching if the original spacing was unknown?

Answer 20

Consult the chart in the AC 43.13-1B