Aircraft coverings and finishes
What is likely to occur if unhydrated wash primer is applied to unpainted aluminum and then about 30 to 40 minutes later a finish topcoat, when the humidity is low?
Corrosion
Which of the following is a hazard associated with sanding on fabric covered surfaces during the finishing process?
Static electricity buildup.
What is the usual cause of runs and sags in aircraft finishes?
Too much material applied in one coat.
Which type of coating typically includes phosphoric acid as one of its components at the time of application?
Wash primer
A correct use for acetone is to
remove grease from fabric.
Fabric rejuvenator is used to
restore the condition of dope coatings.
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.
If registration numbers are to be applied to an aircraft with a letter height of 12 inches, what is the minimum space required for the registration mark N1683C?Note:2/3 x height = character width.1/6 x height = width for 1.1/4 x 2/3 height = spacing.1/6 x height = stroke or line width
52 inches.
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.
What is likely to occur if hydrated wash primer is applied to unpainted aluminum and then about 30 to 40 minutes later a finish topcoat, when the humidity is low?
A glossy, blush-free finish.
Which defect in aircraft finishes may be caused by adverse humidity, drafts, or sudden changes in temperature?
Blushing.
When and how is finishing tape applied on a fabric-covered aircraft?
Doped on after the first or second coat of dope.
How many fabric thicknesses will be found in a French-fell seam?
Four.
Which statement is true regarding paint system compatibility?
Old wash primer coats may be overcoated directly with epoxy finishes.
Which properly applied finish topcoat is the most durable and chemical resistant?
Polyurethane.
What is used to slow the drying time of some finishes and to prevent blush?
Retarder.
Finishing tape (surface tape) is used for what purpose?
To provide additional wear resistance over the edges of fabric forming structures.
Before applying a protective coating to any unpainted clean aluminum, you should
avoid touching the surface with bare hands.
Fungicide and mildewicide additives are important for fabric covered aircraft, such as
cotton and linen.
If masking tape is applied to an aircraft such as for trim spraying, and is left on for several days and/or exposed to heat, it is likely that the tape will
cure to the finish and be very difficult to remove.
Fungicidal dopes are used in aircraft finishing as the
first coat to prevent fabric rotting and are applied thin enough to saturate the fabric.
Moisture, mildew, chemicals, and acids have no effect on
glass fabric
(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
Aluminum-pigment in dope is used primarily to
reflect ultraviolet from the fabric
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.
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.