Removing and replacing components of aircraft electrical power control, distribution and protection systems
Overview
This standard identifies the competences you need to carry out the removal and replacement of components in aircraft electrical power control, distribution and protection systems, in accordance with approved procedures. It covers both fixed wing and rotary winged aircraft and includes units and components associated with AC main power generation, DC power generation, secondary/standby power generation, emergency power back-up equipment and power distribution, as applicable to the aircraft type.
You will be required to select the appropriate tools and equipment to use, based on the operations to be performed and the components to be removed or replaced. The aircraft components will include items such as batteries, generators, alternators, regulators, inverters, transformers, rectifier units, contactors and change-over relays, under-voltage phase sequence units, switches and circuit breakers. The removal and replacement activities will include making all necessary checks to ensure that the components are safely and correctly removed and replaced and that the equipment is left in a safe condition and ready for testing.
Your responsibilities will require you to comply with organisational policy and procedures for the removal and replacement activities undertaken and to report any problems with these activities 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, 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 removal and replacement techniques and procedures for the electrical power control and distribution components, in the relevant aircraft systems. You will understand the removal and replacement methods and procedures and their application, along with the 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 removal and replacement activities and for ensuring that the equipment is replaced to the required standard. In addition, you will have sufficient knowledge of these components to ensure that they are fit for purpose and meet the specifications, thus providing a sound basis for carrying out the replacement to the required specification.
You will understand the safety precautions required when working on the aircraft electrical power control, distribution and protection systems and when using the associated tools and equipment. You will be required to demonstrate safe working practices throughout and will understand the responsibility you owe to yourself and others in the workplace.
Notes To display competence in this standard it is necessary to both remove and replace aircraft electrical power control, distribution and protection components. You must remove components; however, you may fit a replacement component where the original was previously removed by another person.
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 aircraft manuals and publications to carry out the required work
- establish and where appropriate, mark component orientation for re-assembly
- carry out the removal and replacement activities, within the limits of your personal authority
- remove and replace the required components, using approved tools and techniques
- take suitable precautions to prevent damage to components and the surrounding structure
- complete the relevant documentation, in accordance with organisational requirements
- label and store (in an appropriate location) components that require repair
- dispose of waste materials and scrap components, in accordance with approved procedures
- leave the aircraft and the electrical 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 with aircraft electrical power control, distribution and protection systems (including any specific legislation, regulations/codes of practice for the activities, equipment or materials)
- the importance of maintenance on and impact upon ETOpS (extended twin operations procedures) systems, legislation and local procedures
- the hazards associated with removing and replacing aircraft electrical power control, distribution and protection system components and with the tools and equipment used and how to minimise them and reduce any risks
- 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 protective equipment that you need to use for both personal protection (PPE) and protection of the aircraft
- how to extract and use information from aircraft manuals, history/maintenance reports, flight logs, charts, circuit and physical layouts, specifications, symbols used in aircraft electrical power control, distribution and protection systems and other documents needed in the maintenance process
- how to carry out currency/issue checks on the specifications you are working with
- terminology used in aircraft electrical power control, distribution and protection systems and the use of system diagrams and associated symbols
- the principles of operation of the electrical power system being worked on and the performance characteristics and function of the components within the system
the importance of applying electrostatic discharge (ESD) procedures when working on sensitive equipment or devices
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 various mechanical fasteners that are used and their method of removal and replacement (such as threaded fasteners, special securing devices)
- the importance of using the specified fasteners for the installation and why you must not substitute others
- why securing devices need to be locked and labelled and the different methods that are used to remove and install them
- the torque loading requirements of the fasteners and what to do if these loadings are exceeded or not achieved
- the various types of electrical connector that are used, methods of unlocking, orientation indicators and locating and locking in of the connections
- the techniques used to remove components from aircraft electrical power control, distribution and protection systems, without damage to the components or surrounding structure (such as release of pressures/force, proof marking, the need to protect the circuit integrity by covering and labelling exposed circuits)
- the need to correctly label and store components that require repair or overhaul and to check that replaced components have the correct part/identification markings
- the techniques used to position, align, adjust and secure the replaced components to the aircraft, without damage to the components or surrounding structure
- the quality control procedures to be followed during the removal and replacement operations
- procedures for ensuring that you have the correct tools, equipment, components and fasteners for the activities
- methods of lifting, handling and supporting the components/equipment during the removal and replacement activities
- the use of seals, sealant and adhesives and anti-electrolysis barriers, and the precautions to be taken
- why electrical bonding is critical and why it must be both mechanically and electrically secure
- how to conduct any necessary checks to ensure the system integrity, accuracy and quality of the removal and replacement
- the tools and equipment used in the removal and replacement 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
- the problems that can occur with the removal and replacement operations, and how these can be overcome
- how to recognise defects (such as poor seals, misalignment, incorrectly seated plugs and sockets, ineffective fasteners, foreign object damage or contamination)
- 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 removal and replacement activity:
- obtain clearance to work on the aircraft and observe all relevant isolation and safety procedures
- obtain and use the appropriate documentation (such as job instructions, aircraft manuals, technical instructions and other relevant maintenance documentation)
- 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 that all relevant safety devices and mechanical/physical locks are in place (where appropriate)
- obtain the correct tools and equipment for the activity and check that they are in a safe, tested and usable condition and within current certification/calibration date
- use approved removal and replacement techniques and procedures at all times
- where appropriate, apply electrostatic discharge (ESD) protection procedures
- ensure that components and surrounding structures are maintained free from damage and foreign objects
- return all tools and equipment to the correct location on completion of the activities
- leave the aircraft and the electrical power system in a condition ready for testing
Remove aircraft electrical power control, distribution and protection components from three of the following aircraft systems and replace aircraft electrical power control, distribution and protection components in three of the following aircraft systems:
- AC main power generation equipment
- DC power generation equipment
- emergency power back-up equipment
- secondary/standby power generation equipment
- power distribution equipment
During the activities identified in scope 2 above, you must cover the removal and replacement of the following:
Major electrical components: Remove and replace three of the following:
1. generators
2. regulators
3. inverters
4. change-over relays
5. alternators
6. transformer
7. rectifier units
8. main contactors
9. batteries (such as one-shot or flight control DC batteries)
10. electrical power control units
Other electrical components: Remove and replace four of the following:
11. switches
12. batteries (other types)
13. under-voltage phase sequence units
14. wires/cables
15. relays
16. circuit breakers
17. plugs/sockets
18. transducers/sensors
19. other specific components
Carry out all of the following removal and replacement activities:
- disconnecting electrical connections
- checking components for serviceability
- removal of earth bonding
- positioning and aligning replaced components
- removing cable securing devices
- making mechanical connections
- removing bolt securing devices and mechanical fasteners
- making electrical connections
- carrying out earth bonding
- applying and removing covering/protection to exposed components, wires, pipe work or vents
- installing cable securing devices
- tightening fastenings to the required torque
- 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)
Remove and replace aircraft electrical power control, distribution and protection system components, in accordance with one of the following:
- Civil Aviation Authority (CAA)/European Aviation Safety Agency (EASA)
- extended twin operations procedures (ETOpS) (where appropriate)
- Ministry of Defence (MoD)
- Military Aviation Authority (MAA)
- Aerospace Quality Management Standards (AS)
- Federal Aviation Authority (FAA)
- BS, ISO or BSEN standards and procedures
- customer standards and requirements
- company standards and procedures
- aircraft manufacturer's requirements
Complete the relevant paperwork, to include one from the following and pass it to the appropriate people:
- job cards
- computer records
- aircraft service/flight log
- aircraft log
- permit to work/formal risk assessment
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