MARKING GUIDELINE
NATIONAL CERTIFICATE
AIRCRAFT METALWORK THEORY N3
16 NOVEMBER 2012
This marking guideline consists of 7 pages.
Copyright reserved
Please turn over
MARKING GUIDELINE
-2AIRCRAFT METALWORK THEORY N3
T50(E)(N16)T
QUESTION 1
1.1
A
B
C
D
Wire roller
Handle
Slip roll release
Roller adjustment
A slip roll former is used to make a cylinder or a duct
The slip roller consists of three rollers interconnected by gears and
turned by a crank handle
The rollers can be individually adjusted to produce a tight or loose
roll
1.2
A
B
C
D
E
F
(6)
Balance weight
Clamping handle
Slot-adjusting casting screw
Link adjustment screw
Adjustable stop
Bending leaf handle
Name of tool: Cornice brake
1.3
(7)
Barcol tester - It's a handheld tester for testing soft material
It's only necessary to exert a light pressure
of the instrument to the material to drive a
spring-loaded indenter into the material to be tested.
The hardness reading is instantly indicated on the dial.
(2)
[15]
QUESTION 2
2.1
2.2
To protect the base metal against corrosion
To protect the base metal against wear
To produce a desired appearance
To protect the base metal against chemical reactions
To increase the dimensions of the part
To serve as a base for further plating operations
1xxx Pure aluminium
5xxx Magnesium
7xxx Zinc
Copyright reserved
(4)
(6)
[10]
Please turn over
MARKING GUIDELINE
-3AIRCRAFT METALWORK THEORY N3
T50(E)(N16)T
QUESTION 3
3.1
3.2
Each surface is insulated as follows:
At least two coats of zinc chromate are applied to each surface
Next a layer of pressure-sensitive vinyl tape
Smooth the tape to prevent air bubbles from forming
(3)
Anodizing process
ANODIZING: IS AN ELECTROCHEMICAL ACTION BETWEEN ALUMINUM OXIDES ON
THE SURFACE OF THE METAL AND (CRO2) CHROMIC ACID. ELECTRON FLOW IS
NEGATIVE TO POSITIVE CAUSING THE OXIDES TO SOFTEN AND CLING TO THE
ALUMINUM ALLOY SURFACE. THE PART IS THEN DIPPED INTO WARM H2O.
(7)
[10]
QUESTION 4
4.1
Channel gang nut
Simply u-shape channel constructed so that the anchor nuts are inserted and
held in position by the top ledge of the channel
(2)
Anchor nut
It's a self-locking nut with lugs for fastening it to the structure usually by
riveting
(2)
Copyright reserved
Please turn over
MARKING GUIDELINE
-4AIRCRAFT METALWORK THEORY N3
T50(E)(N16)T
4.2
Radius dimpling
4.3
(6)
Coin dimpling
Removal of solid shank rivets
RIVET REMOVAL (SOLID SHANK)
Copyright reserved
(10)
[20]
Please turn over
MARKING GUIDELINE
-5AIRCRAFT METALWORK THEORY N3
T50(E)(N16)T
QUESTION 5
5.1
Transition repair
Outline the repair
Using a router remove the damaged core area
Fabricate a fibreglass honeycomb core to replace the damaged core
Prepare potting compound
Butter the edges of core
Install the buttered core
Prepare glass-fibre adhesive
Prepare four glass-fibre laminates
Apply four glass cloth laminates to repair area
Allow to cure
Apply necessary erosion and corrosion treatment
Copyright reserved
(15)
Please turn over
MARKING GUIDELINE
5.2
-6AIRCRAFT METALWORK THEORY N3
T50(E)(N16)T
Semi-monocoque fuselage construction
(5)
[20]
QUESTION 6
Rectangular to square development
Copyright reserved
Please turn over
MARKING GUIDELINE
-7AIRCRAFT METALWORK THEORY N3
T50(E)(N16)T
[15]
QUESTION 7
7.1
7.2
7.3
7.4
7.5
7.6
7.7
7.8
7.9
7.10
False
True
True
True
True
False
True
False
True
True
[10]
TOTAL:
Copyright reserved
100
Please turn over