Questions and Answers - Aircraft Metal | Aircraft Systems

Questions and Answers - Aircraft Metal

Study Aid Questions

Fill in the Blanks

1. A joint that is too weak cannot be tolerated, but neither can one that is too ______ because it can create stress risers that may cause ______ in other locations.

2. There are six types of stresses: tension, compression, ______, and bearing are known as basic stresses; while bending and ______ (or twisting) are considered combination stresses.

3. There are two ways to determine rivet size: (1) the size of rivets in the next ______ rivet row inboard on the wing and (2) multiple the thickness of the thickest sheet by ______ and use the next larger size.

4. Aircraft structural joint design involves an attempt to find the optimum strength relationship between being critical in ______ and critical in ______.

5. A file with a single row of ______ teeth is called a single‐cut file; whereas files with one row of teeth crossing under another row are called files ______.

6. Files are classified according to their ______. The most common files include: flat, triangle, square, ______, and round.

7. ______ drill motors are recommended for use on projects around flammable materials where potentials spark from a(n) ______ drill motor might become a fire hazard.

8. Properly adjusted drill ______ can prevent excessive drill penetration that might damage the ______ structure or injure personnel.

9. A bar folder is designed for use in making ______ or folds along edges of sheet metal.

10. ______ breaks are used to form thicker more ______ parts.

11. On the slip roll, the front rollers ______ or grip the metal sheet while the rear roll provides the proper ______ to the work.

12. It is advantageous to ______ or even polish the edges of a flange that must undergo even moderate ______ to avoid crack formation.

13. ______ made of hardwood are widely used in airframe metalwork for shrinking and stretching metal, particularly angles and ______.

14. The minimum bend radius is affected by; the kind of material, ______ of the material, and ______ condition of the material.

15. The ______ must be used for all bend that are smaller or larger than ______.

16. In order to form a box, it is necessary to drill ______ at the intersection of the inside bend ______ lines.

17. Machining characteristics of magnesium are ______, making possible the use of maximum speeds of the machine tools with heavy cuts and high ______ rates.

18. Rivets fill the hole during the installation process which provides a good ______ transfer.

19. Blind rivets are installed during ______ where access is not available to form the driven head of ______ rivets.

20. The CherryMax rivet consists of five parts; ______ blind header, hollow rivet shell, ______ collar, driving anvil, and the pulling stem.

21. Collars used with Hi‐Lok fasteners have a ______ break‐off groove which shears off at a predetermined ______, leaving the lower portion of the collar seated with the proper torque.

22. An interference fit is typically used for ______ and ______ fit is used for steel, titanium, and composites.

23. Rivnuts are internally threaded ______ that have a flush or shallow ______ heads.

24. Rivet diameter should not be ______ than 3 times the thickness of the ______ sheet.

25. Rivet ______ is the distance between the centers of ______ rivets in the same row.

26. If countersinking is done on metal below a certain thickness a ______ with less than minimum bearing surface or ______ of the hole may occur.

27. A rivet gun with the correct header must be held snugly against the head and ______ to the surface while the bucking bar of the proper ______ is held against the opposite end.

28. ______ repair is very important because of the load it carries and particular care should be taken to ensure the original ______ of the structure is not impaired.

29. A scale or ______ can be used to check the condition of the upset rivet head to see that it conforms to the proper requirements.

30. ______ dimpling is the process that uses heated dimpling dies so that the material will ______ better during the dimpling process.

Knowledge Application Questions

1 ‐ Matching (answers may be used more than once)

a. Tension    b. Compression    c. Shear
d. Bearing    e. Torsion              f. Bending

1. The force that resists the force that rivets or bolts place on a hole. ______

2. The force per unit area which causes adjacent particles of material to slide past each other. ______

3. A combination of two forces acting upon a structural member at one or more points. ______

4. The force which tends to twist a structural member. ______

5. The force per unit area which tends to stretch a structural member. ______

6. The force per unit area which tends to shorten a structural member at any cross section. ______

7. ______

Tension (Stresses in Structural Members)

8. ______

Bending (Stresses in Structural Members)

9. ______

Torsion (Stresses in Structural Members)

10. ______

Shear (Stresses in Structural Members)

11. ______

Compression (Stresses in Structural Members)

2 ‐ Matching

a. Brinelling    b. Burnishing    c. Burr            d. Corrosion    e. Crack       f. Cut
g. Dent           h. Erosion         i. Chattering    j. Galling         k. Gouge      l. Inclusion
m. Nick           n. Pitting           o. Scratch       p. Score          q. Stain        r. Upsetting

1. Presence of foreign or extraneous material wholly within a portion of metal. ______

2. A small, thin section of metal extending beyond a regular surface. ______

3. Breakdown or deterioration of metal surface by vibratory action. ______

4. A change in color, locally causing a noticeably different appearance. ______

5. Loss of metal, usually to an appreciable depth over a relatively long, narrow area. ______

6. Occurrence of shallow, spherical depressions in a surface. ______

7. A physical separation of two adjacent portions of metal. ______

8. Slight tear or break in metal surface from light contact by a foreign object. ______

9. Indentation in a metal surface produced by an object striking with force. ______

10. Loss of metal from the surface by chemical or electrochemical action. ______

11. Deep tear or break in metal surface from contact under pressure. ______

12. Breakdown of metal surfaces due to excessive friction between two part. ______

13. Local break or notch on edge. ______

14. A displacement of material beyond the normal contour or surface. ______

15. Polishing of one surface by sliding contact with a smooth, hard surface. ______

16. Loss of metal from the surface by mechanical action of foreign object. ______

17. Sharp, localized breakdown of metal surface with defined edges. ______

18. Grooves in a metal surface from contact with foreign material under heavy pressure. ______

3 ‐ Matching

a. scales                 b. combination square       c. dividers
d. rivet spacer         e. marking tool                   f. scribes
g. punches              h. awls                               i. hole duplicator

1. Makes quick and accurate rivet pattern lay‐outs on a sheet. ______

2. Only used when marks will be removed by drilling or cutting. ______

3. A scale with three heads that can be moved to any position on the scale. ______

4. A carbon steel tempered marking tool. ______

5. Comes in lengths most commonly 6” and 12”. ______

6. Used to locate and match existing holes in structures. ______

7. Fiber tipped pen. ______

8. Used in aircraft maintenance to align holes. ______

9. Transfer measurement from a device to a scale to determine its value. ______

4 ‐ Matching

a. prick punch         b. center punch       c. automatic center punch
d. transfer punch    e. pin punch             f. drive punch                      g. chassis punch

1. Has an adjustable cap for regulating the stroke. ______

2. Used to transfer dimensions from a paper pattern directly onto metal. ______

3. Also known as a drift punch. ______

4. Used to mark the locations of new holes using a template or existing holes. ______

5. Used to make holes in sheet metal. ______

6. Used to make large indentations in metal for a twist drill. ______

7. Used to drive out damaged rivets, pins and bolts. ______

5 ‐ Matching
Parts of a drill

1. Body ______                                2. Land ______
3. Cutting Lips ______                     4. Notched Point Chisel Edges ______
5. Flute ______                                6. Shank ______

6 ‐ Matching

a. leg                      b. flange                c. grain of metal          d. bend radius
e. neutral axis        f. mold line             g. mold point               h. bend tangent line
i. setback               j. flat                       k. bend allowance       l. bend line
m. closed angle     n. open angle         o. K factor                   p. total developed

1. Located where the metal starts to bend and the metal stops curving. ______

2. Set even with the nose of the brake and acts as a guide for bending. ______

3. Measured from a radius center to the inside surface of the metal. ______

4. Width of material, measured around the bends from edge to edge. ______

5. The distance from the mold point to the bend tangent line. ______

6. angle that is more than 90° when measured between legs. ______

7. Line formed by extending the outside surface of the leg and flange to a point in space. ______

8. The longer part of a formed angle. ______

9. The curved section of metal within the bend. ______

10. The shorter part of a formed angle. ______

11. Corresponds to one of the angles to which metal can be bent. ______

12. An imaginary line that has the same length after bending as it had before. ______

13. The base measurement minus setback (=MLD‐SB). ______

14. The point of intersection of the mold lines. ______

15. Angle that is more than 90° when the amount of bend is measured. ______

16. Bend should preferably be made to lie at an angle to this width. ______

7 ‐ Matching

a. universal head            b. modified universal head        c. standard 100° flush head
d. reduced flush head     e. modified 120° countersink    f. cherry hollow end E‐Z buck

1. Designed specifically for double‐flush applications. ______

2. Are not to be used where aerodynamics is a factor. ______

3. Designed to limit rivet tipping. ______

4. Replacement for both round and brazier head rivets. ______

5. Sacrifice clamp‐up strength for increased shear strength. ______

6. Ideal for dimpling. ______

8 ‐ Matching

a. 1100 Aluminum     b. 5056 Aluminum    c. 2117 Aluminum   d. 2017 Aluminum
e. 2024 Aluminum     f. 7050 Aluminum     g. Monel

1. ______
Rivet 5056 Aluminum

2. ______
Rivet 2024 Aluminum

3. ______
Rivet 1100 Aluminum

4. ______
Rivet 2017 Aluminum

5. ______
Rivet Monel

6. ______
Rivet 2117 Aluminum

7. ______
Rivet 7050 Aluminum

8. Alloy code‐E 

9. Alloy code‐AD ______

10. Alloy code‐M ______

11. Alloy code‐DD ______

12. Alloy code‐B ______

13. Alloy code‐A ______

9 - Fill In the Blank

Minimum Edge Distance

Edge distance/edge margin

Minimum edge distance

Preferred edge distance

Protruding head  rivets



Countersunk rivets



10 ‐ Fill in the Box

Rivet pitch/spacing

Rivet spacing

Minimum spacing

Preferred spacing

1 and 3 rows protruding head rivet layout



2 row protruding head rivet lay out



1 and 3 rows countersunk head rivet layout



2 row countersunk head rivet lay out



Multiple Choices Questions

1. Repairs must accomplish which of the following?
a. accept stresses, carry them across the repair, and dissipate them in the appropriate area
b. accept stresses, carry them across the repair, and transfer them back to the original structure
c. accept stresses and disperse them throughout the repair
d. accept stresses and prevent a continuous path for stresses to build

2. What is needed when control surface repairs alter the weight distribution?
a. trim tabs are adjusted
b. counter‐balance weight is added
c. balance weights are removed or added
d. balancing patches are used

3. What must be done after holes are drilled in aluminum sheet metal?
a. reamed
b. deburred
c. sanded
d. brushed

4. Lubricants do all of the following except
a. assist in chip removal
b. prolongs drill life
c. prevents overheating
d. assists in dimensional accuracy of the hole

5. Straight line forming machines include all of the following except
a. bar folder
b. cornice break
c. combination break
d. box and pan break

6. What is needed for the press break to bend narrow U‐channels?
a. gooseneck dies
b. offset dies
c. both A & B
d. the press break cannot bend narrow U‐channels

7. What objects can a box and pan break form that a cornice break cannot?
a. box
b. bowl
c. narrow U‐channel
d. hat channel stringers

8. What is an excellent technique for avoiding stresses at the edge of a part?
a. use shims to avoid direct clamping on the part
b. deburring the edges of the part before bending
c. use mild steel instead of annealed aluminum
d. both A & B

9. What is used to support the bumping process?
a. anvil
b. sandbag
c. dies
d. dollies

10. Which of the following is not a factor to consider when forming straight bends?
a. thickness of the material
b. alloy composition
c. setback
d. temper condition

11. For calculation purposes, where is the neutral axis located in terms of thickness?
a. .5T
b. .445T
c. .545T

12. (refer to table below) What is the minimum bend radius of a .063” thick piece of 6061‐T6 aluminum alloy?
a. .16
b. .12
c. .44
d. .03

Minimum bend radius for aluminium alloy

13. What is the formula to calculate bend allowance?
a. BA= 2 (R + 1/2T)
b. BA= 2 (R + 1/2T)
c. BA= 2π (R + 1/2T)

14. How large are relief holes used in forming boxes?
a. 2 times the thickness of the material
b. 2 time the bend radius
c. 2 times the bend angle

15. The distance between the two bends of a joggle is called the
a. neutral axis
b. allowance
c. J‐ intersection

16. What can be done to prevent cracking in the bend area when bending CRES?
a. use a bend radius smaller than recommended in the minimum bend radius table
b. use a bend radius larger than recommended in the minimum bend radius table
c. heat the CRES before bending

17. What rivets are used for joining corrosion resistant steel and titanium parts together?
a. 7050 Aluminum
b. 5056 Aluminum
c. Monel

18. CherryMax rivets are manufactured with all of the following head styles except:
a. universal
b. unisink
c. 120° flush head
d. 130° countersunk

19. All of the following are advantages of Hi‐lok fasteners except:
a. light weight
b. high fatigue resistant
c. high heat tolerance
d. high strength

20. Which of the following is a permanent type fastener assembly that consists of a pin and collar?
a. lockbolt
b. CherryBUCK
c. Taper‐lok
d. Eddie‐bolt

21. Correct rivet installation requires all of the following except:
a. dimpling of the skin
b. good hole preparations
c. removal of burrs
d. clamping the sheets together

22. Transverse pitch is the perpendicular distance between rivet rows and is usually equal to
a. 50% of the rivet pitch
b. 75% of the rivet pitch
c. 90% of the rivet pitch
23. When using a rivet size of 1/8”, what drill size should be used?
a. #40
b. #30
c. #21

24. Which of the following is not a common type of countersunk wells?
a. 82°
b. 120°
c. 110°

25. The NACA riveting method has primary applications in
a. leading edge areas
b. trailing edge areas
c. fuel tank areas

26. What should you be looking for when inspecting rivets?
a. paint chipped off rivet heads
b. smoking or working rivets (black ring around rivet)
c. skin bulging around the rivet
d. all of the above

27. Fuselage stringers extend from the
a. nose to the tail
b. leading edge to the trailing edge
c. wingtip to wingtip

28. The spar is the main supporting member of the
a. fuselage
b. empennage
c. wing

29. What is the purpose of refrigerating 2017 and 2024 aluminum alloy rivets after heat treatment?
a. to accelerate age hardening
b. to relieve internal stresses
c. to retard age hardening

30. The dimensions of an MS20470AD‐4‐8 rivet are
a. 1/8 inch in diameter and ¼ inch long
b. 1/8 inch in diameter and ½ inch long
c. 4/16 inch in diameter and 8/32 inch long

Stresses in Structural Members
Layout Tools
Marking Tools
Hole Duplicator
Cutting Tools
Shop Tools
Hand Cutting Tools
Hole Drilling
Forming Tools
Sheet Metal Holding Devices
Aluminum Alloys
Solid Shank Rivet
Rivet Installation Tools
Special Purpose Fasteners
Forming Process, Operations and Terms
Layout and Forming
Making Straight Line Bends
Using a Sheet Metal Brake to Fold Metal
Folding a Box
Open and Closed Bends
Hand Forming
Basic Principles of Sheet Metal Repair
Repairability of Sheet Metal Structure
Approval of Repair
Typical Repairs for Aircraft Structures - Floats-Corrugated Skin-Panel-Outside & Inside the Member-Panel Edges-Lightening Holes-Pressurized Area-Stringer- Former or Bulkhead
Typical Repairs for Aircraft Structures - Longeron-Spar-Rib and Web-Leading Edge-Trailing Edge-Specialized Repairs-Inspection Openings