-
What metal alloy is most often used in aircraft construction?
aluminum
-
2 basic types of sheet metal structures used on aircraft are?
-
A repair to structure must restore original? (3 things)
-
The 5 basic stresses on an aircraft structure are?
- Tension
- compression
- shear
- torsion
- bending
-
The top of the wing spar is subject to tension or compression during flight?
compression
-
The bottom of the wing is subject to compression or tension during flight?
Tension
-
A torsional stress is a combination of 2 stresses acting in different direction?
-
A properly designed rivet joint is subjected to what 2 stresses and loads?
-
If a properly designed rivet joint fails, the rivet will (shear or pull out of the sheet metal) first?
shear
-
Aircraft structures are most likely to fail at points where stresses (concentrate or release) due to changes in (direction or cross sectional area).
- concentrate
- cross-sectional area
-
To prevent a small crack from spreading you may to what to it?
stop-drill it
-
Aluminum alloys (are or are not) suseptable to corrosion?
are
-
name the primary alloy agent in each aluminum alloy:
2117
2024
5056
7075
- copper
- copper
- magnesium
- zinc
-
Commercially pure aluminum is identified by the number?
1xxx
-
The most common alloy used in structures are?
2024
-
Alclad is made of _______ and rolled onto heat treated aluminum
pure aluminum
-
For alclad to be effective it must be protected from?
scratches
-
When aluminum is heated to its critical temperature and quenched it is (solution or precipitation) heat treated?
Solution
-
Artificial aging is another name for _____ heat treatment.
precipitation
-
Aluminum alloys may be softened or hardened by annealing?
softened
-
What is the temper designation for "as fabricated"
F
-
What is the temper designation for "Annealed"
O
-
What is the temper designation for "Solution heat treated"
T4
-
What is the temper designation for "Solution heat treated and cold worked"
T3
-
What is the temper designation for "Solution heat treated and artificially aged"
T6
-
What is the temper designation for "Strain hardened to quarter temper"
H12
-
What is the temper designation for "Strain hardened to full hard temper"
H18
-
Magnesium is lighter or heavier than aluminum?
Lighter
-
3 drawbacks to magnesium as a structural material are?
- Cracks easily
- Corrodes easily
- Burns readily
-
Titanium is used in areas where high ______ to ______ ratio is needed.
strength to weight
-
Stainless steel is suited to areas of _____ temperature.
High
-
Where is Stainless steel found commonly?
Firewalls , exausts
-
Aluminum alloy faced honeycomb panels are useful as a structural material because of their : 3 things
- high strength
- low weight
- stiffness
-
3 methods of preventing corrosion on aluminum?
- Paint or primer
- Alclad
- covering with an oxide film
-
What are the 3 requirements for corrosion of aluminum
- Potential difference
- electrolyte
- conductive path
-
Pure aluminum will or will not corrode?
will not
-
A protective oxide film will form on aluminum alloy by what 2 means?
- chemically
- electrolyticly
-
What are the 3 groups of stainless steel?
- Austenitic
- martensitic
- ferritic
-
When repairing a puncture in an aluminum honeycomb panel with a doubler, how thick should it be?
1.5 times the original skin thickness
-
Which group of stainless steels are magnetic?
Martensitic
-
which stainless steel group is not heat treatable?
ferritic
-
What is the temper designation for "strain hardened"
H
-
What is the temper designation for "strain hardened and partially annealed"?
H2
-
Designation "Hx4" on aluminum means what?
Strain hardened to half hard
-
Aluminum alloy 3003 has what alloy agent?
manganese
-
6xxx series aluminum is primarily alloyed with?
magnesium and silicon
-
4xxx series aluminum is primarily alloyed with?
silicon
-
5xxx series aluminum is primarily alloyed with?
magnesium
-
7xxx aluminum is primarily alloyed with?
Zinc
-
when using a scale for sheet metal layout you should measure from its end? t or f
false
-
Scribes can be used to mark bend lines? t or f
False , creates stress risers
-
What should be used to layout sheet metal?
wax charcoal pencils or felt markers
-
What can happen if lead pencil is used on hot section parts?
carbon infuses into the metal and weakens it
-
What is used to remove rivet tails?
pin punch
-
When using a deburring tool be careful not to push to hard so as not to ?
countersink
-
What are the color codes for aviation snips?
right
left
straight
-
What is the most common way to cut sheet metal in a shop?
squaring shear
-
What color is a 3/32 cleco clamp?
silver
-
what color are 1/8 " cleco clamps
copper
-
what color are 5/32 cleco clamps
black
-
what color are 3/16 cleco clamps
brass
-
what is commonly used to bend sheet metal?
box brake
-
Rivet lengths are measures in increments of___ and diameters are measured in increments of____.
-
Identify the head shape of ms20426.
countersunk
-
Identify the head shape of ms20470.
universal head
-
Identify the head shape of an430.
round head
-
Identify the head shape of an442.
flat head
-
Prior to installing a an426 rivet the metal must be____ or ____.
-
Identify the alloy of the rivets by the mark on the head.
-no mark
-dimple
-raised dot
-
Identify the alloy of the rivets by the mark on the head.
-raised dashes
-raised crosses
-
Identify the alloy of the rivets by the code.
-A
-B
-AD
-
Identify the alloy of the rivets by the code.
-D
-DD
-E
-
Magnesium skins should be riveted using rivet code__.
B
-
Rivet 2017 , identified by code D are commonly called ?
icebox rivets
-
Rivets that can be installed without access to both sides are called?
blind rivets
-
What is the type of rivet creates a threaded hole for a machine screw once driven?
rivnuts
-
What 3 types of fasteners used on cowlings commonly?
-
On a properly driven rivet the width of the bucked side must be __ times the original size.
1.5
-
On a properly driven rivet the length of the bucked side must be __ times the original diameter size.
.5
-
The head angle of an ms20426 rivet is _____ degrees?
100 degrees
-
When three sheets of metal are dimpled and stacked to be riveted together , they should be ________(coin or radius) dimpled
Coin dimpled
-
What type of dimpling is used on magnesium sheets to prevent them from cracking in the dimpling process?
Hot dimpling
-
An an470dd6 rivet would be driven by a (one shot or fast hitting) rivet gun?
One- shot
-
When practical, bends should be made ( with the grain or across )?
Across the grain
-
Buddy riveting , bad rivet is how many taps?
3 taps
-
Buddy riveting, how many taps for a good rivet?
Two taps
-
Buddy riveting , how many taps to drive the rivet some more?
1tap
-
When installing rivets as per NACA , the manufactured head should be on the inside or outside of the structure?
Inside
-
The point of intersection of the mold lines of two sides of a bend is called?
Mold point
-
The distance from the mold point to the bend tangent line is known as?
Setback
-
For a bend of 90 degrees, the setback is calculated with the formula : setback= ____+____
Br + mt
-
For a bend more or less than 90 degrees, we apply a correction factor known as?
K factor
-
The amount of material actually involved in the bend is known as?
Bend allowance
-
What is done to lightning holes to increase stiffness ?
Flanged
-
In order for sheet metal prices to be flat against skin and yet have one flat on top of another a process called ______ is used.
Joggling
-
Shallow scratches in aluminum may be repaired by?p
Burnishing
-
When repairing a component or part , you should consult the ?
Structure repair manual
-
Why is an octagonal patch preferred to a rectangular patch on a high stressed area?
Provides a more gradual change from the stresses.
-
What can be used to replace a hi-shear rivet if you do not have the tools to do it in the field?
An AN bolt of the right size
-
What tool is used to form a skin patch to the contour of the fuselage ?
Slip roll former
-
When repairing floats , rivets should have this done ?
Dipped in sealant and driven wet
-
A sheet metal repair on a pressurized aircraft may require the use of?
Sealant
-
Prior to cutting an inspection hole be sue it is in a ?
Approved area
-
Control surface repairs must not add weight :
Behind the hinge line
|
|