6. Materials & hardware - Q&A

A 0.5 in. diameter pipe is to be joined using standard nuts and fittings. What coupling would you use?

• AN8-8852-1.
• AN8-8852-2.
• AN8-8852-8.

A worm drive creates

• a drive in 2 planes and transmits both directions.
• a drive in 1 plane but transmits both directions.
• a drive in 2 planes but transmits 1 direction only.

The steepest slope permitted on the scarf of a scarfed plywood repair is

• 1 in 20.
• 1 in 4.
• 1 in 12.

If a sheet of aluminium alloy of 0.032 and 0.064 is to be joined together the rivet should be

• 0.032 plus 2D.
• 0.096 plus 1.5 D.
• 0.064 plus 1D.

In corrosion, the electrode that loses electrons is

• the cathode.
• either the cathode or the anode depending upon the electrolyte.
• the anode.

What is open assembly time?

• The time for which the mixed adhesive stays usable in the pot before it starts to gel.
• The time between the adhesive being applied to the joint surfaces and their assembly.
• The time elapsed from the adhesive being applied to the joint surfaces to them being clamped.

A self aligning bearing is a

• angular bearing.
• precision bearing.
• radial bearing.

Electrochemical reaction is caused by the contact of

• bonding.
• moisture on the surface of the metal.
• dissimilar metals.

A plate 10 inches by 5 inches is to be riveted with 3 rows of rivets, with the normal 4D rivet spacing and 2 D edge distance. The rivets are AN460AD4-6. How many rivets are required?

• 60.
• 52.
• 56.

Specified time of contact between the indentor and test piece in a vickers or brinell hardness test is

• 20 seconds.
• 10 seconds.
• 15 seconds.

A square around the NW digit in the quadrant of a fastner would indicate

• interference fit fastener.
• hi-lock to be used
• fluid tight fastner.

The Fatigue limit for steel is generally in the region of, compared to the static U.T.S

• 40%-60%.
• 60%-80%.
• 20%-40%.

The dimensions of an MS20430AD-4-8 rivets are

• 1/8 inch in diameter and 1/4 inch long.
• 4/16 inch in diameter and 8/32 inch long.
• 1/8 inch in diameter and 1/2 inch long.

A non-electrolytic chemical treatment for aluminium alloys to increase corrosion resistance and paint bonding qualities is called

• alodizing.
• anodizing.
• dichromating.

What would be the diameter and length of a solid rivet if the following markings are given, AS 162-408?

• 1/4 inch dia, 1/2 inch length.
• 1/2 inch dia, 1 inch length.
• 1/8 inch dia, 1/2 inch length.

Excessive stress on fluid or pneumatic metal tubing caused by expansion and contraction due to temperature changes can best be avoided by

• providing bends in the tubing.
• avoiding long straight sections of tubing between fixed parts of the structure of the aircraft.
• Both answers above are correct.

MS20426AD-6-5 indicates a countersunk rivet which has

• a shank length of 5/16 inch (excluding head).
• an overall length of 5/16 inch.
• a shank length of 5/32 inch (excluding head).

In the anodic film inspection and sealing test, if a good seal has been accomplished

• the dye mark will not rub off.
• the dye mark has no importance.
• the dye mark will rub off.

If aluminium alloy is not quenched within the minimum time allowed after heat treatment is it will be

• subject to corrosion.
• malleable.
• brittle.

Which of these is a common cause of corrosion?

• Water in fuel.
• Spilled battery acid.
• Untreated metal.

Which of the following is the definition of cure time?

• The period after which the surface of the compound no longer exhibits adhesive properties.
• The time required for the mixed compound to reach an initial rubbery state.
• Both answers are correct.

Where the edge of a new fabric section will be located within 1 inch of a structural member to which the fabric is attached by rib lacing or other methods, the new fabric section should

• be extended 3 inches past the structural member.
• be extended to meet the structural member.
• be designated a major repair.

When does an aircraft fabric covering repair become a major repair?

• When the repair extends over a wing rib.
• When the repair extends over three adjacent wing ribs.
• When the repair extends over two adjacent wing ribs.

Hydraulic pipes are made from

• 1100 or 2020 H14.
• annealed steel.
• 5056 or 7075.

Colour identification of an aluminium rivet is

• black.
• violet.
• green.