A&P JEPPESEN AIRFRAME CHAPTER 5 AIRCRAFT FABRIC COVERING
What is a tie-off knot?
A standard knot used on all stitches except the starting stitch.
What is the principal advantage of the envelope method for covering wings?
Almost all the seams are machine-sewed by the envelope supplier. (미리 바느질 해서 위에다가 씌우는 방식 - 반대로는 Blanket method가 있음.)
How would you determine the correct spacing for rib stitching if the original spacing was unknown?
Consult the chart in AC 43.13-1B.
What two types of organic fibers are used for covering aircraft?
Cotton and linen.
What types of synthetic fibers are used for covering aircraft?
Fiberglass and heat-shrinkable polyester fibers.
Which of the several types of fabric is unaffected by moisture and mildew(흰 곰팡이)?
Fiberglass.
Name three common types of machine-sewed seams.
French-fell, folded-fell, and plain overlap.
What is the purpose of the selvage edge on a roll of fabric?
It prevents the fabric from unravelling(실 풀림).
Fabric is considered unairworthy when it has deteriorated(변형, 변질된) to what percentage of its original strength?
Less than 70 percents.
Aircraft covering fabrics are made of materials from what two sources?
Organic materials and synthetic materials.
Where would you use surface tape?
Over ribs, sewed seams, around corner, over lapped edges, and along leading and trailing edges.
What is the function or purpose of reinforcing tape?
Reinforcing tape is used between the fabric and the rib stitching(lacing) to prevent the cutting through the fabric.
What are the principle methods used to test the condition of fabric?
Seyboth or Maule tester, and pull test.
What identification marking is found on the the selvage edge, and in which direction is the warp applied?
The FAA-PMA stamp is found on the selvage edge and the warp is applied parallel to the line of flight.
How would you determine the strength requirements for fabric used to recover an aircraft?
The fabric must be of at least the quality and strength of the fabric used by the original manufacturer. (Determined by the quality and strength of the fabric as originally used.)
How are the fabric type and strength requirements determined for fabric covered aircraft?
The original manufacturer determines the fabric type, and the strength requirements are a function of the never exceed speed and wing loading.
How should a structure that will be covered with doped fabric be prepared following inspection and prior to covering?
Treat it with a protective coating of paint or varnish(니스) as appropriate. (Coat the surface with paint or varnish as appropriate.)
Where are anti-tear strips used?
Under wing rib stitching when the never-exceed speed is greater than 250 mph.
What is meant by warp, weft(fill), and bias?
Warp is the direction along the length of the fabric, weft is the fabric at right angles to the warp, and bias is a direction at a 45 degree angle to the warp and weft. (Warp - 직물의 방향, Weft - warp와 수직이 되는 방향, Bias - warp 와 weft의 45도 방향)
How should the edges of drainage(배수), inspection, and ventilation holes be reinforced?
With plastic, aluminum, or brass grommets.