Chapters 00-20
FINS:
1. Equipment on the A/C is generally allocated a unique identifier known as a
Functional Item Number (FIN).
2. The basic element of the FIN is a two-letter code indicating to which system and
circuit the equipment belongs.
3. To this code are added prefixes and/or suffixes which provide the unique
identification for individual equipment.
4. NOTE: Several identical components which perform same function in the same
circuit can be differentiated by the suffix number
5. General rule is that even suffix (2, 4, 6...) identifies a component on right hand side
and odd suffix (1, 3, 5...) is identifying component on left hand side.
6. For mechanical equipment the FIN is similar to the electrical FIN except that the
second letter of the system/circuit identifier becomes an M (for example GM).
Example 14CA1 which is broken down as follows:
14 - Fourteenth component in circuit CA
CA - System/circuit two letter code (Auto thrust Engagement)
1 - Suffix - First of several similar systems (Auto thrust Engagement 1).
01 A/C General:
1. A320 is the original base A/C
2. The A318/A319/A20/A321 are narrow body, twin engine, short / medium range
Aircraft.
3. A318 shortest and A321 longest (A318 height longest higher tail to help with
longitudinal stability).
4. Dark cockpit philosophy in that indicator lights don’t come on when systems in
normal operations and there are no failures.
Leak definitions:
Leak – Sufficient to become a drop or will possibly become a drop.
Leakage – Not sufficient to be a drop.
Stain - Discolour surface.
Unscheduled Maintenance:
Phase 1 is a general inspection for primary damage and indication of remote damage and
most phase 1 inspections are external.
Phase 2 is a more detailed inspection and most phase 2 inspections are internal. It can be
necessary to remove components.
Phase 3 is a very detailed inspection. It can be necessary to remove components and stripdown.
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If there is no damage during phase 1 inspection, no more inspection is necessary.
If you find damage during the phase 1 inspection, then do phase 2 inspection.
If you find damage during the phase 2 inspection, then do phase 3 inspection.
If you find damage during phase 1 or phase 2 inspections, replace or repair the
damaged component (Refer to the applicable manuals (SRM, AMM, CMM)) and
make sure that the adjacent area is not damaged.
Hard landing vs Overweight:
Only difference is Vertical speed.
 Hard landing V/S more than 540 Ft/min
 Overweight V/S more than 360 Ft/min
Lightning generally enters extremity’s I.e. wing tips top tail etc exit trail edge
Structures:
X = Fore and aft distance from any point to STA0.
Y = Lateral distance from any point to aircraft centerline.
Z = Vertical distance from any point to aircraft centerline.
Sta 0 is 2540mm / 254cm/ 100 in Forward of nose. Point of un disturbed airflow
Major Zones:
43 stringers L/H and 43 Stringers R/H 44 in middle common 2 both
Panels ref:
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The first or identification letter identifies the door in a logical sequence, ie. from the
inside to the outside, or from forward to aft. The first identification letter is an 'A' for
each zone.
The second or location letter, gives the location of the door on the aircraft if necessary
121 AL is the first panel in zone 121 on Left side (forward fuselage)
191 AT is the first panel in zone 191 at Top (belly fairing)
T = Top (Upper Surface)
B = Bottom (Lower Surface)
L = Left
R = Right
Z = Internal
F = Floor panel
W = Sidewall panel
C = Ceiling panel