Cat A - Aeroplane Essays
PRESSURIZATION - CAAIP AL 3-23
Pressurization allows for high altitude flying which:
1. Allows the aircraft to avoid bad weather and turbulence
2. Improves the aircrafts fuel economy
But, high altitude temperature, humidity and pressure are not sufficient to support human existence.
Thus, prolonged exposure to these conditions could lead to altitude sickness, anoxia or death
It is for this reason that pressurization provides a habitable environment by:
1.
2.
3.
4.
Providing conditions equivalent to those at 8,000ft
Providing a means of temperature control
Providing a means of ventilation, that prevents build-up of odors
Providing a comfortable rate of cabin altitude change (500fpm up and 300fpm down)
Safety features
Outflow valve: controls and maintains pressurization by discharging air from the cabin in response to
the signals from the controller
Vacuum relief valve: prevents cabin pressure from being appreciably lower than the ambient pressure
Pressure equalization valve: provides a means of equalizing cabin and cargo section pressure
Blow-out panels: prevents the differential pressure from being exceeded between the cargo interior
and exterior
Cabin altitude warning: provides a master caution indication when cabin altitude exceeds 10,000ft
Indication systems: provides a means of monitoring the cabin altitude, differential pressure and rate of
cabin pressure change
Ground safety valve: prevents the aircraft from pressurizing on ground
Oxygen cylinder/supply: provides a means of oxygen supply in event of pressurization system failure
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Cat A - Aeroplane Essays
REPORT
(DAMAGE CAUSED BY GROUND SUPPORT EQUIPMENT)
Aircraft Reg: 5Y-BUY
Serial No: UT876
Aircraft Type: Dash 8
Operator: Camp-nou
Date: 23-Nov-2011
FLIGHT CONTROL DAMAGE (Left Aileron)
On the above mentioned date, the aircraft left aileron was damaged by the refueling truck in WajirKenya, after finishing over-wing refueling.
Initial assessment concluded that the control surface was damaged beyond economical repair, thus
warranting its replacement.
The aircraft is currently assuming A.O.G status awaiting ordered spare for installation
No further damage was found. Damage details entered into the log-book
Full name:
Designation:..
Signature:
Date:
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Cat A - Aeroplane Essays
SYMMETRY CHECK CAAIP AL/7-12
Done to check the relative alignment or adjustment of major aircraft components
Preparation
1.
2.
3.
4.
5.
Consult MM for correct procedure, relevant figures and tolerances
Consult the aircraft logbook for actual dimensions and lengths
Assemble all required tools and equipment
Set the aircraft on a flat level surface
Identify the reference points on the aircraft
Symmetry check Small aircrafts
1. All measurements taken between the reference points, should be done by means of steel-tape
2. A tension of 5 lbs should be used on the steel-tape to improve the accuracy of all readings
Symmetry check large aircrafts
1.
2.
3.
4.
A plumb-bob is used
It is positioned at the reference point and dropped perpendicularly to the ground
On the ground below the plumb-bob a point x is marked
Measure the dimensions between the Xs. that is between:
The nose and nacelle
The nose and wing-tips
Centre of gravity and tail-plane
Fin and wing tips
5. Compare the dimensions to those in the logbook
6. Amend where necessary and issue CRS
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Cat A - Aeroplane Essays
POST LIGHTNING INSPECTION - CAAIP AL/7-1
1. Consult MM for correct procedure, tooling and safety precautions
2. Assemble all the required tools and equipment
3. Carry out detailed visual inspection of the aircraft skin looking out for skin blisters in clusters or
spread out
4. Inspect the aircraft skin and rivets for signs of fretting
5. Inspect all bonding strips for security and integrity
6. By hand move all flying controls looking out for roughness, indicative of bearing seizure as a
result of lightning discharge tracking
7. Check all antennas for signs of discharge damage
8. Inspect cowling for evidence of pitting
9. Inspect all engine oil filters, looking out for metal deposits indicative of bearing failure
10. Inspect the landing gear for residual static discharge indicated by gear magnetism
11. Carry out bonding resistance check
12. Check all COMM and NAV units for proper operation
13. Carry out the relevant entries and issue CRS
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Cat A - Aeroplane Essays
PITOT HEAD INSTALLATION CAAIP AL/10-1
Preparation
1.
2.
3.
4.
5.
6.
7.
Consult MM for correct procedure and safety precautions
Assemble required tools
Inspect the pitot head for damage, corrosion or blockage
Isolate electrical power to the pitot and static systems
Inspect the area of installation for corrosion and damage
Inspect drain holes for blockage
Inspect harness for chaffing
Pre-installation precautions
1.
2.
3.
4.
Ensure that flex hoses dont twist when tightening
Ensure that the rigid lines are not knicked to ensure that they dont give false indication
Great care should be taken so as to ensure that cables are not cross-connected
Do not paint the pitot head
Post installation inspections
1.
2.
3.
4.
5.
Tighten all pressure lines
Carry out pitot static check
Carry out heating functional check
Carry out bonding check
Make relevant entries and issue CRS
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Cat A - Aeroplane Essays
LOGBOOK ENTRY
AIRCRAFT TYPE:
AIRCRAFT REG:
TOTAL HRS:
TOTAL CYCLES:
SERIAL No:
DATE:
TRAILING RUDDER REPLACEMENT
RUDDER PART No 85540002001 REPLACED I.A.W. A.M.M 27-20-11-02. DUE TO ITS EXCESSIVE DAMAGE
ELEVATOR PART No OFF:
85540002001 sn: 133
ELEVATOR PART No ON:
85540002001 sn:331
RUDDER CONTROL SYSTEM RIGGING AND OPERATION CARRIED OUT I.A.W A.M.M 27-20-00-02 AND
FINDINGS CONCLUDED SATISFACTORY.
INSPECTOR:
NAME:
AUTHORITY:
DATE:
AUTHORITY:
DATE:
DUPLICATE INSPECTOR:
NAME:
CERTIFICATE OF RELEASE TO SERVICE
I hereby certify that the work specified above has been carried out in accordance with the current
regulations and in respect of that work the aircraft is ready for release to service.
NAME:
AUTHORITY:
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DATE:
Cat A - Aeroplane Essays
LANDING GEAR SERVICING CAAIP AL/3-2
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
Done to check the fluid level in a strut
Consult the MM for correct procedure
Assemble all required tools
Jack up the aircraft, to take off weight of the strut
Remove the inflation valve cap and release air pressure completely
Remove the valve housing
Compress the strut and check fluid level is at the bottom of filler holes, if not top-up with
approved fluid
Connect hose to the valve and direct the opened end to a container with approved fluid
Extend and compress strut several times to expel air (froth)
Check the strut fluid level
With the strut compressed, install valve housing and inflate strut to specified gas pressure,
checking that the leg extends completely
Lower the aircraft and check that the extension of the inner cylinder is in accordance with the
manufacturer supplied graph
Carry out all required entries and issue CRS
After 5-10 landings inspect the strut for leaks and if required service the strut
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Cat A - Aeroplane Essays
ISOLATION CHECK - CAAIP EEL/1-6
Precautions
1. Refer to routing charts and approved test schedule for the aircraft type
2. All auxiliary equipment should be tested separately I.A.W manufacturers publications
3. Essential safety circuits having a nominal voltage over 30 volts should be tested individually
Preparation
1. Avail a 250 volts insulation tester with a controlled output, so that the testing voltage cannot
exceed 300 volts
2. Disconnect the battery and external power
3. Close all C.Bs Where applicable
4. All switches in the circuit should be ON and dimmer switches set to the minimum resistance
position
5. Items in the circuit with resistance not less than 2 M may be left in the circuit provided the
earth lead is disconnected
6. Bonded earth connections should not be disturbed
7. Components such as cut-outs and relays which are normally open should have their terminals
bridged to ensure continuity
Testing
Double pole system: connect the leads of the insulation tester to each of the battery leads and measure
the resistance, then check the resistance between each battery lead and earth
Single pole system: connect one lead to the insulation tester and one to earth
After testing
1.
2.
3.
4.
Normalize all disturbed circuits
Analyze and record all the results taking into consideration the temperature and humidity
Carry out functional check on all circuits after being tested
Carry out all relevant entries and issue CRS
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Cat A - Aeroplane Essays
INDUCED DRAG
As a result of the pressure difference between the bottom and the top of the aerofoil during
flight, the H.P air at the bottom moves to the L.P area on the top of the aerofoil across the wing
tip
This causes vortices, which remain attached to the aerofoil and act as brakes as they are
dragged along by the aircraft. Induced drag is proportional to lift
1
Induced Drag = 2 . . 2 . .
Its effects can be alleviated by use of winglets
CENTER OF PRESSURE
This is the point through which the resultant lift force acts
With increase in angle of attack up to 10, the C.O.P tends to move forward until it is less than
of the cord from the L.E
With increase in angle of attack above 10, the C.O.P moves rearwards
AERODYNAMIC BALANCE
Developed during manufacture and left undisturbed throughout the control surface life
Its main purpose is to aid the pilot in moving controls by use of the imposed aerodynamic loads
It is found four forms:
I.
Inset hinge
II.
Horn balance
III.
Handley page
IV.
Friese
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Cat A - Aeroplane Essays
HONEYCOMB INSERTION REPAIR - CAAIP AL/7-6
1.
2.
3.
4.
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9.
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12.
13.
14.
15.
16.
17.
18.
Consult the SRM for dimensions, areas and limitations
Assemble all the required tools
Mark the extent of damage
Select a hole saw or router that encloses the area of damage
Remove the damage in a circular or oval shape
Using a hole saw cut a path through the inner skin 0.5 outside the cutout
Peel off the inner skin between the cutout and routed path
Using a grinding disc, grind the honeycomb core down to the bonded surface
Prepare an insert from a panel of the same thickness and strength as original
Deburr all sharp edges
Remove all paint in area of repair and clean the mating surfaces
Mix adhesive
Apply the adhesive to all exposed edges of the core and all mating surfaces of the repair parts
and original skin
Assemble the repair parts
Cure with heat or pressure as specified in SRM
Refinish repair surface
Perform post repair inspection
Complete all associate entries and certify work done
This form of repair is applicable on:
Cowlings
Radome
Floor-boards
Flight controls
10 | C r u s h I n n o v a t i o n s
Cat A - Aeroplane Essays
AXIS AND CONTROL
Normal axis
It passes from the aircraft top to bottom through the C.G
Movement about this axis is known as Yaw displacement
Brought about by pushing the left or right rudder pedal
Ailerons also have a secondary effect on yaw
Pushing the right pedal, kicks the rudder to the right
Thus, developing aerodynamic load as a result of Bernoullis principle to move the fin to the left.
Hence Yawing the aircraft to the right about the center of gravity
Lateral axis
It passes from aircraft wingtip to wingtip through the C.G
Rotation about this axis is known as Pitch displacement
Achieved by pulling or pushing of the control column
Pushing of the control column forward, will cause the elevator to move down and the
corresponding aerodynamic load as a result of the Bernoullis principle will cause the
empennage to lift up
Causing the aircraft to pitch nose-down about the center of gravity
Longitudinal axis
It passes from aircraft nose to tail through the C.G
Rotation about this axis is known as Roll displacement
Achieved by moving the control column left or right
Moving the control column to the right, will cause the right aileron to move up and
simultaneously lower the left aileron
Increasing the lift on one wing and decreasing it on the other
This differential lift causes the aircraft to roll to the right about the center of gravity
11 | C r u s h I n n o v a t i o n s
Cat A - Aeroplane Essays
AIR SPEED INDICATOR SERVICEABILITY CAAIP AL/10-1
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
Consult MM for correct procedure and safety precautions
Remove all covers from the pitot heads and static ports
Visually inspect the pitot mast for signs of damage and check its security of installation
Inspect and ensure that all static ports are clear of obstruction
Inspect all attaching plumbing and electrical connectors for security of installation, knicking or
damage
Drain the pitot system of all moisture
Inspect the instrument panel for security of installation
Inspect the instrument casing mounting and cover for evidence of damage
Check the dial markings, counters and pointers for legibility
Check for presence of moisture inside the instrument covers
Check all associate warning lights and flags for serviceability
Check the heating element for warm-up or carry out current consumption check if an ammeter
is present
Carry out all required entries and issue CRS
12 | C r u s h I n n o v a t i o n s
