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Maintaining indicating and recording systems on aircraft

URN: SEMAE3315
Business Sectors (Suites): Aeronautical Engineering Suite 3
Developed by: Enginuity
Approved on: 2021

Overview

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This standard identifies the competences you need to carry out maintenance activities on aircraft indicating and recording 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 visual display units, instruments, instrument panels and control of those systems which give visual or aural warning of conditions in unrelated systems. It also covers units which record, store or compute data from unrelated systems, and includes systems/units which integrate indicating instruments into a central display system and instruments not related to any specific system. The maintenance activities will include the removal, fitting and testing of a range of aircraft indicating and recording system components. You will be expected to use the approved procedure for correctly isolating the circuit/system. You will 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 indicating and recording systems. You will understand the removal, fitting and testing methods and procedures, and their application, along with the indicating and recording system 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 indicating and recording 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:

  1. This standard is designed to cover the practical experience requirements of the Airline Transport Association (ATA) Chapter 31 Indicating and Recording Systems.
  2. To display competence in this standard, it is necessary to both remove and fit aircraft indicating and recording 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:

  1. work safely at all times, complying with health and safety and other relevant regulations, directives and guidelines
  2. follow the relevant maintenance schedules to carry out the required work
  3. carry out the maintenance activities within the limits of your personal authority
  4. carry out the maintenance activities, and replace components in the specified sequence and in an agreed timescale
  5. report any instances where the maintenance activities cannot be fully met or where there are identified defects outside the planned schedule
  6. complete relevant documentation in accordance with organisational requirements
  7. dispose of waste materials in accordance with safe working practices and approved procedures
  8. 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:

  1. 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)
  2. 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)
  3. the importance of maintenance on indicating and recording systems and the impact upon Extended Range Twin-Engine Operations Procedures (ETOPS) systems, Electrical Wiring interconnect Systems (EWIS), legislation and local procedures
  4. 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
  5. the hazards associated with carrying out maintenance activities on aircraft indication and recording systems, and with the tools and equipment used, and how to minimise them and reduce any risk

  6. the protective equipment that you need to use for both personal protection (PPE) and protection of the aircraft

  7. what constitutes a hazardous voltage and how to recognise victims of electric shock

  8. how to reduce the risks of a phase to earth shock (such as insulated tools, rubber matting and isolating transformers)

  9. 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

  10. 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
  11. how to carry out currency/issue checks on the specifications you are working with
  12. terminology used in aircraft indication and recording systems, and the use of system diagrams and associated symbols
  13. the  principles of operation of the indicating and recording system being worked on, and the function of the various units that make up the system
  14. the techniques used to remove components from aircraft indicating and recording 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)
  15. the various mechanical fasteners to be removed and replaced, and their methods of removal and replacement (such as threaded fasteners, special securing devices)
  16. the various types of electrical connector that are used, methods of unlocking, orientation indicators and locating and locking-in of the connections
  17. the importance of applying electrostatic discharge (ESD) avoidance procedures when working on sensitive equipment or devices
  18. 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
  19. how to fit equipment and components into the system (such as ensuring 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)
  20. how to make adjustments to components/assemblies to ensure that they function correctly (such as zero, range, travel and working clearance)
  21. why securing devices need to be tightened to the correct torque, locked and labelled, and the methods to be used
  22. the tools and equipment used in the maintenance activities, and their calibration/care and control procedures
  23. 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
  24. why electrical bonding is critical and why it must be both mechanically and electrically secure
  25. how to carry out routine checks and servicing of the aircraft indicating and recording system (including checking for security of equipment, changing filters, inspecting for High Intensity Radiated Fields (HIRF) requirements)
  26. the types of test to be carried out on the aircraft indicating and recording system, and the test equipment to be used (such as continuity, voltage and soak tests)
  27. the methods and procedures to be used to carry out the various tests on the indicating and recording system
  28. the importance of carrying out tests in the specified sequence, checking all readings and movements at each stage
  29. how to record the results of each individual test and the documentation that must be used
  30. how to analyse the test results, and how to make valid decisions about the acceptability of the aircraft indicating and recording systems
  31. the procedures to be followed if the equipment or system fails to meet the test specification
  32. 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
  33. the procedure for the safe disposal of waste materials and scrap components
  34. the extent of your own authority and to whom you should report if you have problems that you cannot resolve

Scope/range

Scope Performance

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  1. Carry out all of the following during the maintenance of the aircraft indicating and recording systems:

    1. ensure that appropriate authorisation to work on the aircraft is obtained, and observe all relevant isolation and safety procedures
    2. obtain and use the correct documentation (such as job instructions, technical instructions, aircraft manuals and maintenance documentation)
    3. 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
    4. 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
    5. ensure the safe isolation of the indicating and recording systems before breaking into the system circuit
    6. ensure that the relevant safety devices and mechanical/physical locks are in place (where appropriate)
    7. where appropriate, apply electrostatic discharge (ESD) avoidance procedures
    8. use approved removal, fitting and testing techniques and procedures at all times
    9. return tools and equipment to the correct storage location on completion of the activities
    10. ensure that work carried out is correctly documented and recorded
    11. ensure that any outstanding tests are correctly documented

  2. Carry out maintenance on two of the following parts of aircraft indicating and recording systems:

    1. instrument and control panels (such as instruments, switches, circuit breakers)
    2. independent instruments (such as clocks, inclinometers)
    3. recorders (such as flight recorders, cockpit voice recorders, maintenance recorders)
    4. central computers (such as Digital Core Avionic Systems (DCAS), stored checklists, integrated instrument systems)
    5. central warning system (such as master warning or flight warning systems, central instrument warning, tone generators, annunciators)
    6. central display systems (such as those that give visual display of conditions in unrelated systems)
    7. automatic data reporting systems (such as ASDAR systems)

  3. Remove and fit four different indicating and recording system components (at least two must be from group A):

Group A

1.  flight data recorder (FDR)  
2.  performance/maintenance recorders    
3.  display units
4.  cockpit voice recorder       
5.  Digital Core Avionic Systems (DCAS) 
6.  inclinometer
7.  master caution unit   
8.  generators (such as pulse, speed/taco, tone) 
9.  quick access recorder (QAR)
10.  independent instruments (such as clocks)

Group B
11. transmitters (such as position, flow, pressure, level)  
12. computers 
13. gauges/indicators
14. switches (such as micro, proximity)         
15. relays               
16. capacitance units
17. input and follow-up potentiometers   
18. transducers/sensors 
19. wires/cables
20. actuators                    
21. circuit breakers  
22. plugs/sockets
23. motors
24. other specific component

  1. Carry out fifteen of the following maintenance activities:

    1. removing access panels and covers to expose components to be removed
    2. carrying out fault diagnosis and system checks
    3. preparing the system for maintenance (such as isolating)
    4. disconnecting electrical connections                   
    5. refitting components in the correct position, orientation and alignment
    6. removal of bonding            
    7. removing cable securing devices         
    8. setting and adjusting replaced components (such as zero, range, travel, clearance)
    9. removing securing devices and mechanical fasteners           
    10. supporting equipment to be removed          
    11. making mechanical connections
    12. dismantling equipment to an appropriate level      
    13. making electrical connections
    14. covering (protecting) exposed components, wires, pipework or vents    
    15. carrying out bonding
    16. torque loading
    17. checking components for serviceability      
    18. installing cable securing devices
    19. replacing damaged/defective components    
    20. carrying out functional checks of the system
    21. ensuring that replacement components have the correct part numbers
    22. labelling (and storing in the correct location) components that require repair or overhaul
    23. applying bolt locking methods (such as split pins, wire locking, lock nuts)
    24. carrying out area inspections prior to task close down

  2. Carry out two of the following tests on the aircraft indicating and recording systems:

    1. continuity check                       
    2. built in test equipment BITE test
    3. voltage check                    
    4. 'special-to-type' tests
    5. compass swing                            
    6. check swing
    7. comparison check

Using three of the following:
8. measuring equipment                                           
9. 'special-to-type' test sets
10. external power source (such as electrical/hydraulic) 
11. aircraft power source (such as electrical/hydraulic)
12. pitot/static pump/digital air data test equipment

  1. Complete the relevant paperwork, to include one from the following and pass it to the appropriate people:

    1. job cards/work sheets
    2. computer records
    3. aircraft technical log
    4. aircraft cabin log
    5. aircraft log book

  2. Carry out maintenance on aircraft indicating and recording systems in compliance with one of the following:

    1. Civil Aviation Authority (CAA)/European Aviation Safety Agency (EASA)
    2. Extended Range Twin-Engine Operations Procedures (ETOPS) (where appropriate)
    3. Ministry of Defence (MoD)
    4. Military Aviation Authority (MAA)
    5. Aerospace Quality Management Standards (AS)
    6. Federal Aviation Authority (FAA)
    7. aircraft maintenance manual/approved change documentation (service bulletin)
    8. manufacturers standards and procedures

Scope Knowledge

Values

Behaviours

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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

Skills

Glossary

Links To Other NOS

External Links

Version Number

3

Indicative Review Date

2024

Validity

Current

Status

Original

Originating Organisation

Enginuity

Original URN

SEMAE3315

Relevant Occupations

Engineer, Engineering, Engineering and Manufacturing Technologies, Engineering Technicians

SOC Code

5234

Keywords

engineering; aeronautical; aircraft indicating and recording systems; visual display units; instruments; instrument panels; safety precautions