[FAA] FAA题库之Airframe

001. When and how is finishing tape applied on a fabric-covered aircraft?

        Doped on after the first or the second coat of dope
Finishing tape (surface tape) is applied to the wing surface with dope and is usually stuck down after the first or the second coat of dope has been applied.

002. 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
When making a repair to an L-shaped tear in aircraft fabric, use a curved needle and well-waxed thread.
Start at the apex (center) of the tear and make baseball stitches every quarter inch to the end of the tear.
After both sides of the tear have been stitched, remove the colored and silver dopes by softening them with dope thinner or acetone.
Dope on a patch that extends at least 1-1/2 inch beyond all edges of the tear.

003. 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% of the original strength for intermediate fabric
Aircraft fabric is allowed to deteriorate to 70% of its required strength. When an airplane requiring intermediate fabric, whose new tensile strength is 65 pounds per inch, is covered with grade-A fabric whose new strength is 80 pounds per inch, the fabric can deteriorate to 70% of the strength of new intermediate fabric, or 46 pounds per inch, before it must be replaced.

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

        tensile strength
The strength of aircraft covering fabric is based on its tensile strength.

005. Fabric rejuvenator is used to

        Restore the condition of dope coatings
Rejuvenator is a dopelike finishing material that has powerful solvents and plasticizers.
When a doped surface has aged and cracked, its resilience can be restored with rejuvenator. Rejuvenation does nothing to restore strength to deteriorated fabric.

006. (1) Machine-sewn seams in aircraft covering fabrics may be of the folded-fell or French-fell types.
        (2) A plain lapped seam is never permissible.
Regarding the above statements,
          Only No.1 is true
Statement (1) is true. Machine-sewn seams in aircraft covering fabrics may be of the folded-fell or French-fell types.
Statement (2) is not true. A plain lapped seam is satisfactory where selvage edges or pinked edges are joined.

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

        Four
In a French-fell, machine-sewed seam used to join aircraft fabric, the edges of the fabric are folded over each other so the threads of the double row of stitches passes through four thicknesses of fabric.

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

        Glass fabric
Glass cloth used as an aircraft structural material is not affected by moisture, mildew, chemicals, or acids. It is also fire resistant.

009. 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 weight of the fabric approved for use on an aircraft structure is determined by the never-exceed speed of the aircraft and by its maximum wing loading.

010. When dope-proofing the parts of the aircraft structure that come in contact with doped fabric, which of the following provide an acceptable protective coating?
1. Aluminum foil.
2. Resin impregnated cloth tape.
3. Any one-part type metal primer.
4. Cellulose tape.

           1 and 4
Dope proofing a structure is done by covering all the parts that will come in contact with doped fabric with a protective coating such as aluminum foil or cellulose tape.

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

         To provide additional wear resistance over the edges of fabric forming structures
Surface tape, or finishing tape, should be placed over all lacing, seams, (both machine- and hand-sewn), corners, edges, and places where wear is likely to occur.