Maintaining engine indicating systems on aircraft
Overview
This standard identifies the competences you need to carry out maintenance activities on aircraft engine indicating systems, in accordance with the approved aircraft maintenance manual, approved change documentation (service bulletin) and airworthiness requirements. It covers both fixed wing and rotary winged aircraft, and includes units, components and associated systems which indicate engine operation. The units and components will include indicators, transmitters, analysers, phase detectors, instruments/gauges, amplifiers, generators, display units, transmitters, receivers and computers. The maintenance activities will include the removal, fitting and testing of a range of aircraft engine indicating system components. You will be expected to use the approved procedure for correctly isolating the circuit/system, and to remove the required components and fit approved replacements, as appropriate. You will then need to test and adjust the completed system to meet the aircraft maintenance manual, change documentation (service bulletin) and airworthiness requirements.
Your responsibilities will require you to comply with the specific practices and procedures identified in the aircraft manual, change/service bulletin documentation and airworthiness requirements for the maintenance activities undertaken, and to report any problems with these requirements that you cannot personally resolve, or that are outside your permitted authority, to the relevant people. You must ensure that all tools, equipment and materials used are correctly accounted for on completion of the activities, and that all necessary job/task documentation is completed thoroughly, accurately and legibly. You will be expected to work with a minimum of supervision, taking personal responsibility for your own actions and for the quality and accuracy of the work that you carry out.
Your underpinning knowledge will provide a good understanding of your work, and will provide an informed approach to applying the appropriate maintenance techniques and procedures to aircraft engine indicating systems. You will understand the removal, fitting and testing methods and procedures, and their application, along with the engine indicating systems maintenance requirements. You will know how the equipment functions, the common problems that can occur, the purpose of the individual components and associated defects, in adequate depth to provide a sound basis for carrying out the maintenance activities, correcting faults and for ensuring that the equipment is maintained to the required standard.
You will understand the safety precautions required when working on aircraft engine indicating systems. You will be required to demonstrate safe working practices throughout, and will understand your responsibility for taking the necessary safeguards to protect yourself and others in the workplace.
Notes:
- This standard is designed to cover the practical experience requirements of the Airline Transport Association (ATA) Chapter 77 Engine Indicating Systems.
- To display competence in this standard, it is necessary to both remove and fit aircraft engine indicating system components. You must remove components; however, you may fit a replacement component where the original was previously removed by another person. You should also be aware of how to leave a system in a safe condition if maintenance tasks cannot be completed. This covers both the physical systems and the job documentation.
Performance criteria
You must be able to:
- work safely at all times, complying with health and safety and other relevant regulations, directives and guidelines
- follow the relevant maintenance schedules to carry out the required work
- carry out the maintenance activities within the limits of your personal authority
- carry out the maintenance activities, and replace components in the specified sequence and in an agreed timescale
- report any instances where the maintenance activities cannot be fully met or where there are identified defects outside the planned schedule
- complete relevant documentation in accordance with organisational requirements
- dispose of waste materials in accordance with safe working practices and approved procedures
- leave the aircraft and system in a safe and appropriate condition, free from foreign object debris on completion of the activities
Knowledge and Understanding
You need to know and understand:
- the specific safety practices and procedures that you need to observe when working on aircraft indication and recording systems (including any specific legislation, regulations/codes of practice for the activities, equipment or materials)
- the need to check that cabin/cockpit switches, selectors and circuit breakers are in the correct position before applying any form of external power (such as electrical, hydraulic, air or vacuum)
- the importance of maintenance on aircraft engine indicating systems, and impact upon Extended Range Twin-Engine Operations Procedures (ETOPS) systems, Electrical Wiring Interconnect Systems (EWIS), legislation and local procedures
- the requirements and importance of understanding and applying human factors as defined by the regulatory requirements and the potential impact if these are not adhered to
- the hazards associated with carrying out maintenance activities on aircraft engine indication systems, and with the tools and equipment used, and how to minimise them and reduce any risk
the protective equipment that you need to use for both personal protection (PPE) and protection of the aircraft
what constitutes a hazardous voltage and how to recognise victims of electric shock
how to reduce the risks of a phase to earth shock (such as insulated tools, rubber matting and isolating transformers)
the importance of aircraft husbandry and of ensuring that, throughout the maintenance activity, the aircraft and work area are maintained free from foreign objects, and the implications of FOD to the safety of the aircraft
how to extract and use information from aircraft manuals, log books, flight logs, charts, circuit and physical layouts, specifications, symbols used in aircraft indication and recording systems, and other documents needed in the maintenance activities
- how to carry out currency/issue checks on the specifications you are working with
- terminology used in aircraft engine indication systems, and the use of system diagrams and associated symbols
- the principles of operation of the engine indicating system being worked on, and the function of the various units that make up the system
- the techniques used to remove components from the aircraft engine indicating systems without damage to the components or surrounding structure (such as removal of components and the need to protect the circuit integrity by labelling and covering exposed circuits)
- the various mechanical fasteners to be removed and replaced, and their methods of removal and replacement (such as threaded fasteners, special securing devices)
- the various types of electrical connector that are used, methods of unlocking, orientation indicators and locating and locking-in of the connections
- the importance of applying electrostatic discharge (ESD) avoidance procedures when working on sensitive equipment or devices
- the need to label and store correctly components that require repair or overhaul, and to check that replacement components have the correct part/identification markings and accompanying release documentation
- how to fit equipment and components into the system (such as ensuring the correct position and orientation; ensuring the correct tightness of fastenings; eliminating stress on cables; correctly making electrical connections; carrying out visual checks of all components)
- how to make adjustments to components/assemblies to ensure that they function correctly (such as zero, range, travel and working clearance)
- why securing devices need to be tightened to the correct torque, locked and labelled, and the different methods that are used
- the tools and equipment used in the maintenance activities, and their calibration/care and control procedures
- why tool/equipment control is critical and what to do if a tool or piece of equipment is unaccounted for on completion of the activities
- why electrical bonding is critical, and why it must be both mechanically and electrically secure
- how to carry out routine checks and servicing of the aircraft engine indicating system (including checking for security of equipment)
- the types of test to be carried out on the aircraft engine indicating system (such as continuity, voltage) and the test equipment to be used
- the methods and procedures to be used to carry out the various tests on the engine indicating system
- how to record the results of each individual test and the documentation that must be used
- how to analyse the test results and how to make valid decisions about the acceptability of the aircraft engine indicating systems
- the procedures to be followed if the equipment or system fails to meet the test specification
- the recording documentation to be completed for the activities undertaken and where appropriate, the importance of marking and identifying specific pieces of work in relation to the documentation
- the procedure for the safe disposal of waste materials and scrap components
- the extent of your own authority and to whom you should report if you have problems that you cannot resolve
Scope/range
Scope Performance
Carry out all of the following during the maintenance of the aircraft engine indicating systems:
- ensure that appropriate authorisation to work on the aircraft is obtained, and observe all relevant isolation and safety procedures
- obtain and use the correct documentation (such as job instructions, technical instructions, aircraft manuals and maintenance documentation)
- obtain the correct tools and equipment for the activity, and check that they are in a safe, tested and usable condition and within current calibration dates
- adhere to procedures or systems in place for risk assessment, COSHH, personal protective equipment and other relevant safety regulations and procedures to realise a safe system of work
- ensure the safe isolation of the engine indicating systems before breaking into the system circuit
- ensure that the relevant safety devices and mechanical/physical locks are in place (where appropriate)
- where appropriate, apply electrostatic discharge (ESD) avoidance procedures
- use approved removal, fitting and testing techniques and procedures at all times
- return tools and equipment to the correct storage location on completion of the activities
- ensure that work carried out is correctly documented and recorded
- ensure that any outstanding tests are correctly documented
Carry out maintenance on four of the following parts of the aircraft engine indicating systems:
- power indicating system
- engine revs per minute (RPM)
- inter turbine temperature
- engine pressure ratio (EPR)
- cylinder head temperature
- chip detection
- engine brake mean effective pressure/torque
- engine exhaust gas temperature
- bleed air
- turbine inlet temperature
- ignition analyser
- manifold pressure (MP)
- turbine blade temperature
- vibration analyser
- oil pressure indication
- Nf tacho
- integrated instrument systems
- fuel flow indication
- Ng tacho
- engine temperature
- engine oil pressure/ temperature/quantity
- system wiring
Remove and fit four different aircraft indicating/recording system components (at least two must be from group A):
Group A
1. display units
2. amplifiers
3. analysers
4. computers
5. generators (such as pulse, speed/tacho, tone)
6. phase detectors
7. instruments/gauges
8. thermocouples
Group B
9. transmitters (such as temperature, flow, pressure, vibration)
10. relays
11. wires/cables
12. capacitance units
13. plugs/sockets
14. receivers
15. transducers/sensors
16. switches (such as micro, proximity)
17. circuit breakers
18. input and follow-up devices
19. other specific components
Carry out fifteen of the following maintenance activities:
- removing access panels and covers to expose components to be removed
- carrying out fault diagnosis and system checks
- preparing the system for maintenance (such as isolating)
- disconnecting electrical connections
- refitting components in the correct position, orientation and alignment
- removal of bonding
- removing cable securing devices
- setting and adjusting replaced components (such as zero, range, travel, clearance)
- removing securing devices and mechanical fasteners
- supporting equipment to be removed
- making mechanical connections
- dismantling equipment to an appropriate level
- making electrical connections
- covering (protecting) exposed components, wires, pipework or vents
- carrying out bonding
- torque loading
- checking components for serviceability
- installing cable securing devices
- replacing damaged/defective components
- carrying out functional checks of the system
- ensuring that replacement components have the correct part numbers
- labelling (and storing in the correct location) components that require repair or overhaul
- applying bolt locking methods (such as split pins, wire locking, lock nuts)
- carrying out area inspections prior to task close down
Carry out two of the following tests on the aircraft engine indicating systems:
- continuity check
- leak test
- voltage check
- engine run
- comparison check
- built in test equipment BITE test
- vibration analysis
- 'special-to-type' tests
- functional test
Using two of the following:
10. measuring equipment
11. 'special-to-type' test sets
12. external power source (such as electrical/hydraulic)
13. aircraft power source (such as electrical/hydraulic)
14. pitot/static pump/digital air data test equipment
Complete the relevant paperwork, to include one from the following and pass it to the appropriate people:
- job cards/work sheets
- computer records
- aircraft technical log
- aircraft cabin log
- aircraft log book
Carry out maintenance on aircraft engine indicating systems in compliance with one of the following:
- Civil Aviation Authority (CAA)/European Aviation Safety Agency (EASA)
- Extended Range Twin-Engine Operations Procedures (ETOPS) (where appropriate)
- Ministry of Defence (MoD)
- Military Aviation Authority (MAA)
- Aerospace Quality Management Standards (AS)
- Federal Aviation Authority (FAA)
- aircraft maintenance manual/approved change documentation (service bulletin)
- manufacturers standards and procedures
Scope Knowledge
Values
Behaviours
You will be able to apply the appropriate behaviours required in the workplace to meet the job profile and overall company objectives, such as:
- strong work ethic
- positive attitude
- team player
- dependability
- responsibility
- honesty
- integrity
- motivation
- commitment