Non-Metallic Structures Flashcards
How do you detect decay in a wood structure?
Stick a sharp-pointed knife blade in the suspect area and pry the wood up. If the wood is good, it will come up as a long splinter, if it is decayed it will come up as a chunk.
Are mineral streaks in a piece of structural aircraft wood reason for rejecting the wood?
No, if there is no evidence of decay in the wood.
How is compression wood identified?
It has a high specific gravity, it appears to have an excessive growth of summerwood, and it has little contrast between springwood and
summerwood.
Is a hard knot that is 1/2-inch in diameter allowed if it is in the web of a wing spar?
No, 3/8-inch diameter is the maximum allowable knot, and it must meet severe restrictions.
Are pin knot clusters allowable in aircraft structural wood?
Yes, if they cause only a small effect on grain direction.
What are two advantages of laminated construction over riveted sheet metal?
Light weight and rigidity.
What are two popular types of core material used in laminated structure?
Foam and honeycomb.
What are two popular types of matrix material used in laminated structure?
Polyester and epoxy resins.
What are the two parts of a polyester matrix material?
Resin and catalyst.
What are the two parts of an epoxy matrix material?
Resin and hardener.
What are three materials that may be used to reinforce the matrix material for aircraft structure?
Fiberglass, Kevlar®, and graphite.
What is meant by a unidirectional fabric?
A fabric in which all of the major fibers run in the same direction.
What is meant by the ribbon direction of a honeycomb material?
The direction in a piece of honeycomb material that is parallel to the length of the strips of material that make up the core.
What kind of repair can be made to a small damage of the core material and one face sheet of a piece of aluminum alloy honeycomb structure?
A potted compound repair.
How do you grind the point of a twist drill that is to be used for drilling transparent acrylic material?
The cutting edge should be dubbed off to a zero rake angle, and the in- cluded angle of the tip should be ground to 140 degrees.
What is a warp clock in a structural repair manual?
An alignment indicator to show the orientation of the plies of a composite material. The ply direction is shown in relation to a reference direction.
What are two types of repair to a damaged honeycomb core composite material?
Room-temperature cure repair and hot-bond repair.
What are the critical areas of inspection on seat belts, shoulder harnesses, and aircraft upholstery?
- Verify that seat belts are manufactured in accordance with TSO C22.
- Inspect belt webbing for fraying and tears.
- Inspect buckles and inserts for condition and wear.
- Inspect upholstery for condition and wear. Replace upholstery only with fire-resistant materials approved for aircraft use.
