General: Aircraft Materials, Hardware and Processes

Aircraft bolts are usually manufactured with a

class 3 fit for the threads.

Which heat-treating operation would be performed when the surface of the metal is changed chemically by introducing a high carbide or nitride content?

Case hardening.

Which of the following is a main determinant of the dwell time to use when conducting a due or fluorescent penetrant inspection?

The size and shape of the discontinuities being looked for.

The aluminum code number 1100 identifies what type of aluminum?

99 percent commercially pure aluminum.

A particular component is attached to the aircraft structure by the use of an aircraft bolt and a castle tension nut combination. if the cotter pin hole does no \t align within the recommended torque range, the acceptable practice is to

change washers and try again.

(Refer to Figure 44.) Identify the weld caused by an excessive amount of acetylene.

3.

(Refer to Figure 45.) What type weld is shown at G?

Lap.

How is a clevis bolt used with a fork-end cable terminal secured?

With a shear nut tightened to a snug fit, but with not strain imposed on the fork and safetied with a cotter pin.

What may be used to check the stem on a poppet-type valve for stretch?

Micrometer.

A bolt with a single raised dash on the head is classified as an

AN corrosion-resistant steel bolt.

What type of corrosion may attack the grain boundries of aluminum alloys when the heat treatment process has been improperly accomplished?

Intergranular.

What nondestructive testing method requires little or no part preparation, is sued to detect surface or near-surface defects in most metals, and may also be used to separate metals or alloys and their heat-treat conditions?

Eddy current inspection.

Aircraft bolts with a cross or asterisk marked on the bolthead are

standard steel bolts.

(1) An aircraft part may be demagnetized by subjecting it to a magnetizing force from alternating current that is gradually reduced in strength. (2) An aircraft part may be demagnetized by subjecting it to a magnetizing force from direct current that is alternately reversed in direction and gradually reduced in strength. Regarding the above, statement,

both No. 1 and No. 2 are true.

(1) In nondestructive testing, a discontinuity may be defined as an interruption in the normal physical structure or configuration of a part. (2) A discontinuity may or may not affect the usefulness of a part. Regarding the above statements,

both No. 1 and No. 2 are true.

A fiber-type, self-locking nut must never be used on an aircraft if the bolt is

subject to rotation.

What two types of indicating mediums are available for magnetic particle inspection?

Wet and dry process materials.

What is generally used in the construction of aircraft engine firewalls?

Stainless steel.

(Refer to Figure 45.) What type weld is shown at A?

Butt.

How is the locking feature of the fiber-type locknut obtained?

By the use of an unthreaded fiber locking insert.

Which of the following defects are not acceptable for metal lines?

(1) Cracked flare (2) Seams (3) Dent in the heel of a bend less than 20% of the diameter (5) Dents in the straight section that are 20% of tube diameter.

On a fillet weld, the penetration requirement includes what percentage(s) of the base metal thickness?

25 to 50 percent.

If it is necessary to accurately measure the diameter of a hole approximately 1/4 inch in diameter, the mechanic should use a

small-hole gauge and determine the size of the hole by taking a micrometer reading of the ball end of the gauge.

Which condition indicates a part has cooled too quickly after being welded?

Cracking adjacent to the weld.

What precision measuring tool is used for measuring crankpin and main bearing journals for out-of-round wear?

Micrometer caliper

(Refer to Figure 49.) The measurement reading on the micrometer is

.2792.

When checking an item with the magnetic particle inspection method, circular and longitudinal magnetization should be used to

reveal all possible defects.

Which number represents the vernier scale graduation of a micrometer?

.0001.

Holes and a few projecting globules are found in a weld. What action should be taken?

Remove all the old weld, and reweld the joint.

The testing medium that is generally used in magnetic particle inspection utilizes a ferromagnetic material that has

high permeability and low retentivity.

The clearance between the piston rings and the ring lands is measured with a

thickness gauge.

Which of the following methods may be suitable to use to detect cracks open to the surface in aluminum forgings and castings?

(1) Dye penetrant inspection (4) Eddy current inspection (5) Ultrasonic inspection (6) Visual inspection.

What defects will be detected by magnetizing a part using continuous longitudinal magnetization with a cable?

Defects perpendicular to the long axis of the part.

What method of magnetic particle inspection is sued most often to inspect aircraft parts for invisible cracks and other defects?

Continuous.

Which statement relating to the residual magnetizing inspection method is true?

It may be used with steels which have been heat treated for stressed applications.

(Refer to Figure 47.) What is the measurement reading on the vernier caliper scale?

1.436 inches.

Which type crack can be detected by magnetic particle inspection using either circular or longitudinal magnetization?

45 degrees.

(Refer to Figure 44.) Select the illustration which depicts a cold weld.

2

Identify the correct statement.

Dividers do not provide a reading when used a measuring device.

The core material of Alclad 2024-T4 is

heat-treated aluminum alloy, and the surface material is commercially pure aluminum.

Unless otherwise specified, torque values for tightening aircraft nuts and bolts relate to

clean,dry threads.

What tool is generally used to set a divider to an exact dimension?

Machinist scale.

The pattern for an inclusion is a magnetic particle buildup forming

parallel lines.

Which material cannot be heat treated repeatedly without harmful effects?

Clad aluminum alloy.

Why is steel tempered after being hardened?

To relieve its internal stresses and reduce its brittleness.

Which heat-treating process of metal produces a hard, wear-resistant surface over a strong, tough core?

Case hardening.

Why is it considered good practice to normalize a part after welding?

To relieve internal stresses developed within the base metal.

The Society of Automotive Engineers (SAE) and the American Iron and Steel Institute use a numeral index system to identify the composition of various steels. In the number 4130 designating chromium molybdenum steel, the first digit indicates the

basic alloying element.

One way a part may be demagnetized after magnetic particle inspection is by

slowly moving the part out an ac magnetic field of sufficient strength.

In performing a dye penetrant inspection, the developer

acts as a blotter to produce a visible indication.

In examining and evaluating a welded joint, a mechanic should be familiar with

likely ambient exposure conditions and intended use of the part, along with type of weld and original part material composition.

Liquid penetrant inspection methods may be used on which of the following?

Ferrous and nonferrous metals, and nonporous plastics.

Generally speaking, bolt grip lengths should be

equal to the thickness of the material which is fastened together.

(Refer to Figure 43.) Identify the clevis bolt illustrated.

3

The reheating of a heat treated metal, such as with a welding torch

can significantly alter a metal's properties in the reheated area.

Magnetic particle inspection is used primarily to detect

flaw on or near the surface.

Alclad is a metal consisting of

pure aluminum surface layers on an aluminum alloy core.

A part which is being prepared for dye penetrant inspection should be cleaned with

a volatile petroleum-base solvent.

Where is an AN clevis bolt used in an airplane?

Only for shear load applications.

Select a characteristic of a good gas weld.

The weld should taper off smoothly into the base metal.

To detect a minute crack using dye penetrant inspection usually requires

a longer-than-normal penetrating time.

What tool is generally used to calibrate a micrometer or check its accuracy?

Gauge block.

A bolt with an X inside a triangle on the head is classified as an

NAS close tolerance bolt.

One characteristic of a good weld is that no oxide should be formed on the base metal at a distance form the weld of more than

1/2 inch.

What metal has special short-time heat properties and is used in the constructions of aircraft firewalls?

Titanium alloy.

(Refer to Figure 42.) Which of the bolthead code markings shown identifies an AN corrosion resistant steel bolt?

3

(Refer to Figure 48.) What does the micrometer read?

.3004

(Refer to Figure 45.) What type weld is shown at B?

Double butt.

Which tool can be used to determine piston pin out-of-round wear?

Micrometer caliper.

Which statement regarding aircraft bolts is correct?

In general, bolt grip lengths should equal the material thickness.

Which of the following occurs when a mechanical force is repeatedly applied to most metals at room temperature, such as rolling, hammering, or bending?

(3) The metals become cold worked, strain or work hardened.

The side clearances of piston rings are measured with a

thickness gauge.

Which of these nondestructive testing methods is suitable for the inspection of most metals, plastics, and ceramics for surface and subsurface defects?

Ultrasonic inspection.

Which tool can be used to measure the alignment of a rotor shaft or the plane of rotation of a disk?

Dial indicator.

Which of the following materials may be inspected using the magnetic particle inspection method?

(3) Iron alloys.

How many of these factors are considered essential knowledge for x-ray exposure?

Three

Which of the following describe the effects of annealing steel and aluminum alloys?

(1) decrease in internal stress (2) softening of the metal.

The twist of a connecting rod is checked by installing push-fit arbors in both ends, supported by parallel steel bars on a surface plate. Measurements are taken between the arbor and the parallel bar with a

thickness gauge.

Under magnetic particle inspection, a part will be identified as having a fatigue crack under which condition?

The discontinuity is found in a highly stressed area of the part.

Normalizing is a process of heat treating

iron-based metals only.

Circular magnetization of a part can be used to detect which defects?

Defects parallel to the long axis of the part.

How can the dimensional inspection of a bearing in a rocker arm be accomplished

Telescopic gauge and micrometer.

A mechanic has completed a bonded honeycomb repair using the potted compound repair technique. What nondestructive testing method is used to determine the soundness of the repair after the repair has cured?

Metallic ring test.

In magnetic particle inspection, a flaw that is perpendicular to the magnetic field flux lines generally cause

a large disruption in the magnetic field.

(Refer to Figure 46.) The measurement reading on the illustrated micrometer is

0.2851

What aluminum alloy designations indicate that the metal has received no hardening or tempering treatment?

3002-F.

Why should an aircraft maintenance technician be familiar with weld nomenclature?

In order to gain familiarity with the welding technique, filler material, and temperature range used.

In the four-digit aluminum index system number 2024, the first digit indicates

the major alloying element.

Which tool is used to measure the clearance between a surface plate and a relatively narrow surface being checked for flatness?

Thickness gauge.

If dye penetrant inspection indications are not sharp and clear, the most probable cause is that the part

was not thoroughly washed before the developer was applied.

What is descriptive of the annealing process of steel during an d after it has been annealed?

Slow cooling; low strength.

Unless otherwise specified or required, aircraft bolts should be installed so that the bolthead is

upward, or in forward direction.

Which tool is used to find the center of a shaft or other cylindrical work?

combination set.

When the specific toque value for nuts is not given, where can the recommended torque value be found?

AC 43.13-1B.