Carrying out maintenance on aircraft electrical/electronic systems by component replacement

URN: SEMAER208
Business Sectors (Suites): Aeronautical Engineering Suite 2
Developed by: Enginuity
Approved: 2026

Overview

This standard identifies the competences you need to carry out electronic component replacement on commercial, military or light aircraft, both fixed wing and rotary, in accordance with approved procedures. You will be required to select the appropriate tools and equipment to use, based on the maintenance activities to be carried out, and to check that they are in a safe and serviceable condition. You will be required to prepare the aircraft for work, and this will involve obtaining permission to work on the aircraft, ensuring that all safety pins and warning notices are in place, and ensuring that the relevant systems are in a suitable condition for work to be undertaken.  The maintenance activities will involve the replacement of a number of electrical, electronic or avionic modules or components from the following systems: power and distribution, lighting, engine control and indication, flight control, Pitot static, radar equipment, navigational equipment, communication equipment, defensive aids, undercarriage, and cabin equipment such as for catering and entertainment.

Your responsibilities will require you to comply with organisational policy and procedures for the maintenance activities undertaken, and to report any problems with these activities that you cannot personally resolve, or are outside your permitted authority, to the relevant people. You will be expected to work either with a high level of supervision or as a member of a team, and you will take personal responsibility for your own actions and for the quality and accuracy of the work that you carry out. You must demonstrate a significant personal contribution during the team activities, in order to satisfy the requirements of this standard, and competency in all the areas required by the standard must be demonstrated.

Your underpinning knowledge will be sufficient to provide a sound basis for your work and will provide an informed approach to applying the appropriate maintenance techniques and procedures. You will have a basic understanding of the systems being maintained, and their application, and will know about the maintenance equipment and fastening devices, in adequate depth to provide a sound basis for carrying out the activities to the required specification.

You will understand the safety precautions required when carrying out the aircraft maintenance operations, especially those for isolating and depressurising equipment, and for protecting yourself and others from injury. You will be required to demonstrate safe working practices throughout and will understand the responsibility you owe to yourself and others in the workplace.


Performance criteria

You must be able to:

P1    work safely at all times, complying with health and safety and other relevant regulations, directives and guidelines

P2    follow the relevant maintenance schedules and prepare to carry out the required work

P3    carry out the maintenance activities within the limits of your personal authority

P4    carry out the maintenance activities and component replacement in the specified sequence and in an agreed time scale

P5    report any instances where the maintenance activities cannot be fully met or where there are identified defects outside the planned schedule

P6    complete and store all relevant documentation in accordance with organisational requirements 

P7    dispose of waste materials in line with organisational and environmentally safe procedures


Knowledge and Understanding

You need to know and understand:

K1    how to work safely at all times, complying with health and safety and other relevant regulations, directives and guidelines

K2    the authorisation you require to commence work on the aircraft

K3    the hazards associated with working on aircraft systems (particularly high energy ignition units) and how they can be minimised

K4    the importance of wearing the appropriate personal protective equipment (PPE), and of keeping the work area clean and tidy

K5    the maintenance schedules and servicing specifications that are used during servicing and maintenance, and the importance of following the procedures listed in these documents

K6    the basic principle of operation of the equipment/circuits being maintained, and the purpose of individual components within the circuit

K7    the electrical components to be replaced, and the methods of replacement

K8    electrical bonding/earthing specifications, and their importance

K9    how to take electrostatic discharge (ESD) precautions, and why are they needed

K10    the application and use of a range of electrical components

K11    the adjustments/corrections/tuning required to the components that have been removed/replaced

K12    how to check that the replacement components meet the required specification/operating conditions

K13    how to identify the components to be used, and how to ensure that systems are not contaminated

K14    the quality control procedures to be followed during the maintenance procedures

K15    how to conduct any necessary checks to ensure the system integrity and functionality

K16    the issues that can occur with the servicing and maintenance activities, and how these can be overcome

K17    the importance of correct securing and locking of connections

K18    the importance of tool control, and company tool control procedures

K19    the methods and equipment used to maintain aircraft systems, and how to check that the equipment is within its current certification dates

K20    the tools and equipment used in the maintenance activities, and their calibration/care and control procedures

K21    the importance of ensuring that, when the maintenance is completed, the aircraft is free from dirt, swarf and foreign objects (FOD)

K22    the disposal methods for waste oil, fuel, other liquids and waste

K23    issues with the maintenance procedures, and the importance of informing appropriate people of defects

K24    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

K25    the extent of your own responsibility, and to whom you should report if you have problems that you cannot resolve


Scope/range


Scope Performance

  1. Carry out all of the following during the aircraft electrical, electronic or avionic maintenance activities:
    1. use the correct issue of the aircraft servicing or maintenance schedule
    2. adhere to procedures or systems in place for risk assessment, personal protective equipment and other relevant safety regulations and procedures to realise a safe system of work
    3. check the calibration dates of tools and equipment to be used
    4. return all tools and equipment to the correct location
    5. leave the work area in a safe and tidy condition
    6.   Prepare the aircraft for work by carrying out all of the following:
    7. obtain clearance to work on the aircraft, and observe the power isolation and safety procedures
    8. identify defects for maintenance and ensure the aircraft is fit for maintenance from the aircraft documentation
    9. ensure that relevant safety warnings are in place
    10. ensure that appropriate safety locks/pins are in place
    11. check that the relevant systems are in a condition for work, and for component replacement to take place
  2. Carry out component replacements on three of the following aircraft electrical, electronic or avionic systems:
    1. aircraft power and distribution
    2. radar
    3. lighting
    4. navigation
    5. engine control and indication
    6. communication
    7. flight control
    8. defensive aids
    9. Pitot static
    10. undercarriage
    11. cabin equipment (such as catering, entertainment)
  3. Carry out ten of the following maintenance activities, as applicable to the equipment being maintained:
    1. isolating power
    2. removing excessive dirt and grime
    3. dismantling equipment to unit/component level
    4. use of special-to-type tools
    5. proof-marking/labelling of components/units
    6. de-pressurisation of the system
    7. replacing all damaged or defective units/components
    8. reassembly of the equipment/system
    9. replacing damaged wires or cables
    10. reconnecting electrical connections
    11. replacing damaged or defective connectors
    12. making fluid connections to components
    13. checking the integrity of all connections
    14. looming of cables
    15. checking the integrity and security of earth bonding
    16. inspecting and cleaning sensors
    17. tuning or making routine adjustments to components
    18. servicing battery systems
    19. securing components using mechanical fasteners and applying bolt locking methods
    20. making electrical connections (such as soldering, splicing and crimping)
    21. making static or functional checks of completed systems
  4. Replace a range of electrical, electronic or avionic modules/components, involving the disconnection and reconnection of eight of the following:
    1. mechanical units
    2. quick release fasteners
    3. electrical connectors (such as terminal blocks, male to female plug-in connectors)
    4. backplate connectors
    5. Pitot/static connectors
    6. radio frequency (RF) connectors
    7. fluid system connectors (such as pipes, unions, hoses)
    8. switches (such as micro, pressure)
    9. avionic units
    10. earth and bonding leads
    11. mechanical controls (such as actuating mechanisms, brackets)
    12. other specific components
  5. Carry out maintenance work which complies with one of the following standards
    1. Civil Aviation Authority (CAA)/European Aviation Safety Agency (EASA)
    2. Ministry of Defence (MoD)                                  
    3. Military Aviation Authority (MAA)
    4. Aerospace Quality Management Standards (AS)
    5. customer standards and requirements
    6. Federal Aviation Authority (FAA)                        
    7. organisational standards and procedures
    8. BS, ISO or BSEN standards and procedures
    9. manufacturers standards and procedures
  6. Complete the relevant paperwork, to include one from the following, and pass it to the appropriate people:
    1. maintenance schedule/log
    2. job cards
    3. aircraft service/flight log
    4. other specific recording method

Scope Knowledge


Values


Behaviours


Skills


Glossary


Links To Other NOS


External Links


Version Number

3

Indicative Review Date

2029

Validity

Current

Status

Original

Originating Organisation

Enginuity

Original URN

SEMAER2-08

Relevant Occupations

Engineering, Engineering and Manufacturing Technologies, Engineering Professionals, Science and Engineering Technicians

SOC Code

5234

Keywords

Aeronautical; Engineering; power and distribution; lighting; engine control and indication; flight control; Pitot static; radar equipment; navigational equipment; communication equipment; defensive aids; undercarriage; and cabin equipment