Color coding of hydraulic system

To Enhance the understanding of a hydraulic system, a standardized color coding of flows and pressures was established by the Joint Industry Conference (JIC) and American National Standards Institute (ANSI).


RED

Signifies Operation system pressure.of of the fluid, often used for the piping extends form the pump, to the pressure relief valve, to the first component that restricts the flow.

BLUE
Blue is used to show the fluid is not restricted, indicating there is minimal fluid pressure

GREEN
Green signifies the intake fluid from piped form the reservoir to the pump.

YELLOW
Yellow illustrates the controlled (metered) fluid flow after it passed through the restriction valve.

ORANGE
Orange shows the fluid that has been reduced from the system pressure, such as the fluid at the output of a pressure regulated valve.

VIOLET indicates the increased fluid pressure as a result of a amplified system pressure. eg: Fluid at thee output of the intensifier.

WHITE is to show is the fluid pressure in the system is zero or no pressure. Eg: fuild at the output of the intensifier when pump its not operational.

Minimum Equipment list (MEL)

The Minimum Equipment List (MEL) is a document and method prepared by aircraft operators. MEL is use to obtain relief from Aviation Regulations requiring that all equipment installed on the aircraft be operative at the time of flight.
Image result for minimum equipment list
MEL is aircraft specific. which means different from aircraftto aircraft.The minimum equipment list (MEL ) will specify the circumstances under which a particular aircraft can fly with equipment non-operative as deferred defects. It will specify the condition of the rest of the system (if part of the system is affected) and the condition of the rest of any associated systems. It will detail as appropriate such things as flight duration times, performance limitations etc. See also Tech Logs.
Sometimes called Dispatch Deviation List (DDL).There will also be a list of certification limits (CDL) putting limitations on the use of the aircraft with that deferred defect.
The MEL is developed from the Master Minimum Equipment List (MMEL), MMEL is produced  by the aircraft manufacturer and approved during certification of the airplane.

 

Master Minimum Equipment list

Aircraft minimum Equipment list ( MEL )

Aircraft minimum Equipment list ( MEL )

MMELs are produced by the constructor for all recent aircraft types, exceeding 2730kg MTOM and are applicable to particular types of aircraft, but they do not take into consideration the varying operating conditions of individual operators.
MELs are produced by the individual operators using MMELs as the basis, and then approved by the CAA. They must be no less restrictive than MMELs, and are usually more restrictive.
When approved the MELs become part of the Flight/Operations Manual.
Amendments are permitted only if approved by the CAA.
When an aircraft is allowed to fly with a defect – this is listed along with details of the flight, eg duration; whether over the sea or not; etc. When an ETOPS aircraft is flown on an ETOPS flight the Minimum Equipment List will be restricted.

How to perform a Wheel Change

In this video we will see how to perform an Aircraft wheel change.

A. Safety Precautions

(1) Put the safety barriers in position.
(2) Put the warning notice in the cockpit to tell persons not to operate the landing gear.
(3) Make sure that the wheel chocks are in position.

B. Wheel Assembly Check (to be accomplished prior to wheel removal)

(1) Check wheel assembly for missing, broken or loose tie-bolts.
CAUTION : TIRES ON WHEEL ASSEMBLIES WITH MISSING, BROKEN OR LOOSE
TIE- BOLTS MUST BE DEFLATED BEFORE AXLE NUT IS LOOSENED.
FAILURE TO DEFLATE TIRE BEFORE AXLE NUT IS REMOVED CAN
RESULT IN INJURY SHOULD WHEEL SEPARATE.

C. Open, safety and tag this(these) circuit breaker(s):

121VU HYDRAULIC/BRK FAN/WHEELS/3 AND 4
121VU HYDRAULIC/BRK FAN/WHEELS/1 AND 2
121VU HYDRAULIC/BRK/FAN/CTL

D. Aircraft Maintenance Configuration
(1) Make sure that the PARK BRK control switch is set to ON.
NOTE : On the panel 400VU, make sure that brake pressure indication on the Yellow brake-pressure triple indicator is correct.
If necessary pressurize the brake accumulator with Yellow pump (Ref. TASK 29-10-00-863-002).

(2) Lift the related axle with a jack.

(3) Fully deflate the tire.
NOTE : If you must remove the wheel for access it is not necessary to deflate the tire if:
– the tire is in the correct condition and
– the tire pressure is in the Normal Operating Range
(Ref. TASK 32-41-00-210-003).
If you have not these two conditions you must deflate the tire.

4 . Procedure – Removal

A. Preparation of the Wheel before Removal

(1) Remove the fan

(2) Remove the joint

B. Removal of the Wheel

(1) Remove and discard the cotter pins (4).
(2) Remove the nuts (5), the washer (6) and the bolts (8).
(3) Remove the axle nut (7) with the ADAPTOR MLG
(4) Install the PROTECTOR
(5) Apply a thin layer of COMMON GREASE  on the axle protector.
(6) Remove the wheel.

4 . Procedure – Installation

If the wheel is equipped with a pressure sensor seal cap, make sure
that the seal cap is properly installed and secured with nut and
cotter pin.

A.make sure you are taking the right tire..

B. Preparation of the Wheel before Installation.

MAKE SURE THAT THE GREASE USED FOR THE AXLE SLEEVE IS THE SAME
AS THE GREASE USED FOR THE BEARINGS (CONE AND CAGE). IF YOU USE
A DIFFERENT GREASE, YOU CAN CAUSE DAMAGE TO THE BEARINGS.

prepare A dolly..

make sure the thread protector is installed.

(1) Align the wheel (1) with the driving keys on the brake rotor and
install the wheel.
(2) Remove the PROTECTOR (F46754-1000).
(3) Install the axle nut (7) on the axle and tighten it with the ADAPTOR
MLG (H47682).
(4) In the cockpit, set the PARK BRK control switch to OFF.
(5) Turn the wheel in the direction of the axle nut rotation and TORQUE
the axle nut IAW AMM.

(6) Prevent the rotation of the wheel and loosen the axle nut (7) to
IAW AMM.
(7) Turn the wheel in the direction of the axle nut rotation and TORQUE the axle nut (7) to IAW AMM.
(8) Tighten the axle nut (7) until the holes in the nut are aligned with the holes in the axle.
(9) Install the bolts (8), the washers (6) and the nuts (5).
NOTE : Install the heads of the bolts (8) in the axle.
(10) TORQUE the nuts (5) to IAW AMM.
(11) Install the cotter pins (4).
(12) Turn the wheel manually to make sure that it is installed correctly.


 

 

 

 

HIGH INTENSITY RADIATED FIELD (HIRF)

Discuss the methods of protection against HIRF and the checks/ inspections which would be carried out after a fault was entered in the technical log.

INTRODUCTION

High Intensity Radiated Field (HIRF) is produced by high energy systems located on the ground and occurs at all frequencies. It affects any electronic and digital systems on the aircraft, causing affected systems to operate erratically.

PROTECTION

Aircraft and systems can be protected against HIRF by
proper shielding of cables,EMI filters, good bonding, electro static discharger. Proper termination of aircraft system connectors and sealing of LRUs conducting surface on windows, screening of cables.

CHECKS/  INSPECTIONS

If a fault had been entered in the technical log as HIRF I would make the aircraft safe in accordance with the Aircraft Maintenance Manual (AMM) and raise any other paper work required. I would attempt to isolate the fault, debrief the air crew, if necessary and confirm it is HIRF and not just a fault with the systems involved. The technical log could be consulted to establish if there is a pattern of previous similar faults. If HIRF appeared to be the cause I would check the serviceability of EMI filters, continuity check of shielding and bonding and carry out BITE (Built In Test Equipment) tests where possible to rectify the defect. And also check for the following:

  • Detailed bonding resistance.
  • Using loop resistance tester to measure the loop resistance/ impedance measurement.
  • Disassemble the connector to detect corrosion.
  • Arrange to reconfirm loop position within the limit. Carry out related system functional test.

 

CERTIFICATION

Any work carried out would be recorded and signed as the job progressed. If any items were replaced crosscheck the EASA Form 1 or FAA 8130-3 for items airworthiness conformity and would be attached to paper work, part numbers GRN’s,serial numbers on and off would be recorded. CRS would be issued by a appropriately authorized engineer and a statement would be made in the technical log to monitor the systems affected on the next flights.

REPORTING

As any occurrence of HIRF is an incident this must be reported to the CAA through the Mandatory Occurrence Report (MOR) scheme. I would also report it to the organisation HIRF programme.

ATA Chapters

ATA (Air transportation Association) published a numbering system to learn and understand the technical features of an Aircraft. ATA chapters makes it easy to categorize technical information.

ATA Specification 2200

ATA CHAPTERS

NUMBER CHAPTER
1 GENERAL DESCRIPTION
2 GENERAL REQUIREMENTS
3 STRUCTURE DEIGN CRITERIA
4 PERFORMANCE
5 TIME LIMITS AND MAINTENANCE CHECKS
6 DIMENSIONS AND AREAS
7 LIFTING AND SHORING
8 LEVELING WEIGHING
9 TOWING AND TAXIING
10 PARKING MOORING, STORAGE AND RETURN TO SERVICE
11 PLACARDS
12 SERVICING
13 WEIGHT
14 INTERCHANGEABILITY
15 HUMAN FACTORS
16 NOISE
17 FLIGHT CHARACTERISTIC
18 VIBRATION AND NOISE ANALYSIS (HELICOPTER ONLY)
19 PERFORM WITH MISSING/ SERVICABLE EQUIPMENT
20 STANDARD PRACTICES AIRFRAME
21 AIR CONDITIONING
22 AUTO PILOT
23 COMMUNICATION
24 ELECTRICAL POWER EQUIPMENTS AND FURNISHING
25 EQUIPMENT/FURNISHINGS
26 FIRE PROTECTION
27 FLIGHT CONTROL
28 FUEL
29 HYDRAULIC POWER
30 ICE AND RAIN PROTECTION
31 INSTRUMENTS
32 LANDING GEAR
33 LIGHTS
34 NAVIGATION
35 OXYGEN
36 PNEUMATIC
37 VACUM
38 WATER AND WASTE
39 ELECTRICAL – ELECTRONIC PANELS AND MULTIPURPOSE COMPONENTS
40 MULTISYSTEM
41 WATER BALLAST
42 INTEGRATED MODULAR AVIONICS*
43 *RESERVED
44 CABIN SYSTEMS*
45 DIAGNOSTIC AND MAINTENANCE SYSTEM
46 INFORMATION SYSTEM
47 NITROGEN GENERATION SYSTEM
48 IN FLIGHT FUEL DISPENSING
49 AIRBONE AUXILLARY POWER
50 CARGO AND ACCESSORY COMPARTMENTS
51 STANDARD PRACTICES AND STRUCTURES
52 DOORS
53 FUSELAGE
54 NACELLES AND PYLONS
55 STABILIZER
56 WINDOWS
57 WINGS
58 *RESERVED
59 *RESERVED
60 STANDARD PRACTICES – PROPELLER
61 PROPELLERS
62 ROTOR(S)
63 ROTOR DRIVE(S)
64 TAIL ROTOR
65 TAIL ROTOR DRIVE
66 ROTOR BLADE AND TAIL PYLON FOLDING
67 ROTORS FIGHT CONTROL
68 *RESERVED
69 *RESERVED
70 STANDARD PRACTICES – ENGINES
71 POWERPLANT
72 ENGINE
73 ENGINE FUEL AND CONTROL
74 IGNITION
75 ENGINE AIR
76 ENGINE CONTROL
77 ENGINE INDICATION
78 ENGINE EXHAUST
79 ENGINE OIL
80 ENGINE STARTING
81 TURBINES
82 ENGINE WATER INJECTION
83 ACCESSORY GEAR BOX
84 PROPULSION AUGMENTATION
85 FUEL CELL SYSTEMS
86 *RESERVED
87 *RESERVED
88 *RESERVED
89 *RESERVED
90 *RESERVED
91 CHARTS
92 ELECTRICAL SYSTEM INSTALLATION
93 *RESERVED
94 *RESERVED
95 *RESERVED
96 *RESERVED
97 *RESERVED
98 RECURRING SYSTEM BULLETIN AND AD NOTE
99 ONE TIME SERVICE BULLETIN AND AD NOTE
115 FLIGHT SIMULATOR SYSTEMS

Aircraft Maintenance interview Questions

  • What is a liquid metal?
  • Are thermal protection systems of space crafts commonly composed of one panel or a collection of smaller tiles?
  • What is the highest temperature the space shuttle under surface experiences during its mission?
  • Explain how you overcame a major obstacle?
  • What is SPICE? Where was it developed?
  • What are the main areas in Aviation?
  • What made you choose aircraft maintenance engineering/aerospace engineer line as your career?
  • Explain the day to day responsibilities of Aerospace engineering?
  • Reasons for why patch work are in round in shape?
  • How would you handle if your co-worker is not co-operating with you?
  • What would you do if your Captain is not following the instructions properly?
  • How many types of emergency landings are there and explain?
  • How important is to get the passengers switch off the mobile phones and laptops during land off? What could be the consequences?
  • What interests and abilities would help me as an Aircraft Maintenance Engineer?

Aircraft Engineer Salary

Salary of an Aircraft maintenance personal will differ from place to place. Depending on the experience, qualification and the location.

UNITED KINGDOM

Average annual Salary of a C Licensed Aircraft  Engineer £40,000.
Average annual Salary of a B Licensed Aircraft  technician £36,000.
Average annual Salary of a A Licensed Aircraft Mechanic £28000.
Average annual Salary of an unlicensed Aircraft Mechanic  £21000.

FRANCE

Average annual pay of a C Licensed Aircraft  Engineer £53,000.
Average annual pay of a B Licensed Aircraft  technician £45,000.
Average annual pay of a A Licensed Aircraft Mechanic £28000.
Average annual pay of an unlicensed Aircraft Mechanic  £21000.

UNITED STATE OF AMERICA

in the USA average annual pay of an Airframe and Powerplant mechanic is $50,000 ( $33,463 – $77,109 ). with a normal hour rate of $25 and $35 for overtime.

Aircraft mechanic salary

CANADA

in Canada average annual allowance of an Aircraft Maintenance Engineer is c$ 50,000 ( c$36,786 – c$78,935 ). with a normal hour rate of c$26  and c$35 for overtime.

AUSTRALIA.

Average annual pay of a C Licensed Aircraft  Engineer $115,000.
Average annual pay of a B Licensed Aircraft  technician $85,000.
Average annual pay of a A Licensed Aircraft Mechanic £67,000.
Average annual pay of an unlicensed Aircraft Mechanic  $65,000.

MALAYSIA

in MALAYSIA average annual pay of an contracted Licensed AME is $56000  ( $44,786 – $71,935 ). with a normal hour rate of $34. Locally Bond engineers getting a salary around $25000.Technicians with less experience are making around $9600 with overtime. Senior technicians might make around $13000.

GULF COUNTRIES  

United Arab Emirates, Oman, Kuwait, Qatar, Saudi Arabia, And Bahrain are the GCC. while the engineers pay are quite  uniform. Technician or mechanic salary might have huge differences depending on their experience skills and knowledge. But these salaries are not subject to TAX.

Average annual Salary of an Expat Licensed AME $80000.
Average annual Salary of an Expat Aircraft  technician $45000.
Average annual Salary of a Expat Aircraft Mechanic (less experienced) $21500.

SINAGPORE.

Average annual income of an Expat Licensed AME $63,000.
Average annual income of an Expat Aircraft  technician $30,000.
Average annual income of a Expat Aircraft Mechanic (less experienced) $18,500.


INDIA, PAKISTAN, SRI LANKA, BANGLADESH

Most Probably the terrible place to start an AME career.. Extremely hard to find a job for a fresher.. lots of political  influence is required to get in to major airline. the small airline may not pay salary for freshers.

Average annual income of an Licensed AME $37,000.
Average annual income of an  Aircraft  technician $7,300.
Average annual income of a Aircraft Mechanic (less experienced) $1,500.

 

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