Modifying aircraft avionic systems
Overview
This standard identifies the competences you need to modify aircraft electrical/avionic systems, in accordance with approved procedures. In carrying out the modification operations, you will be required to follow laid-down procedures and to use specific modification leaflets, service bulletins and latest issue drawings and standards. It covers both fixed wing and rotary winged aircraft and you will be required to change, modify and update aircraft avionic systems such as electrical power generation and distribution, internal and external lighting, indication and gauging, pitot static, communication, navigational, armament, passive warning and electronic countermeasure, infra-red and optical systems, radar, and flight guidance and control, as applicable to the aircraft type.
You will be expected to remove and replace existing cables, add new cables, change breakout points and change the routeing of cables. You will also be expected to change components such as units and trays. You will need to show proficiency using various tools for cutting, stripping, crimping and soldering, and for the installation of the avionic systems.
Your responsibilities will require you to comply with organisational policy and procedures for the modifications undertaken, and to report any problems with the modification activities, components or equipment that you cannot personally resolve, or that are outside your permitted authority, to the relevant people. You will be expected to work with a minimum of supervision, taking full 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 modification procedures to aircraft avionic systems. You will understand the modifications to be carried out, and their application, and will know about the modification methods, tools and equipment to be used, in adequate depth to provide a sound basis for carrying out the activities, correcting faults and ensuring that the modification is carried out to the required specification.
You will understand the safety precautions required when carrying out the modifications. You will be required to demonstrate safe working practices throughout, and will understand the responsibility you owe to yourself and others in the workplace.
Note This standard is intended to cover avionic modifications of a significant or complex nature. The level of complexity will include the size and timescale of the modification, the tolerances required, the variety of equipment, techniques and materials required and the difficulty of access. It must not be used solely for simple modifications, such as changes to, or the addition of, a single wire/cable or termination.
Performance criteria
You must be able to:
- work safely at all times, complying with health and safety and other relevant regulations, directives and guidelines
- obtain and follow the relevant modification specifications and job instructions
- confirm and agree what modifications are to be carried out to meet the specification
- prepare the avionic system for the required modification
- carry out the system modification, using approved materials, methods and procedures
- complete the modification within the agreed timescale
- ensure that the modified avionic system meets the specified operating conditions
- deal promptly and effectively with problems within your control, and report those that cannot be solved
- leave the aircraft and the avionic system in a safe and appropriate condition, free from foreign object debris on completion of the activities
- complete the relevant documentation, in accordance with organisational requirements
Knowledge and Understanding
You need to know and understand:
- the specific safety precautions and procedures to be observed whilst carrying out the modifications to aircraft electrical/avionic systems (including any specific legislation, regulations or codes of practice relating to the activities, equipment or materials)
- the importance of maintenance on and impact upon (extended twin operations procedures) ETOpS systems, legislation and local procedures
- the health and safety requirements of the work area in which you are carrying out the modification activities and the responsibility these requirements place on you
- the hazards associated with carrying out modifications to aircraft electrical/avionic systems 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 personal protective equipment and clothing (PPE) to be worn during the modification activities
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 types of drawing and specification that are used during the modification
- how to identify the components to be used; component identification systems (such as codes and component orientation indicators)
- preparations to be undertaken on the system prior to modification
- the importance of applying electrostatic discharge (ESD) procedures when working on sensitive equipment or devices
- the methods and techniques to be used for soldering and de-soldering, and the importance of adhering to the procedures
- the methods and techniques to be used for crimping and heat shrinking, and the importance of adhering to them
- the methods and techniques to be used for the assembly of screened and unscreened plugs and sockets
- how to identify the difference between composite and metal plugs and sockets
- the different types of cable protection, and reasons for each type
- the various mechanical fasteners that will be used and their method of installation
the importance of using the specified fasteners for the modification and why you must not use substitutes
the quality control procedures to be followed during the modification operations
- how to conduct any necessary checks to ensure the accuracy and quality of the modification
- how to recognise defects (such as misalignment, ineffective fasteners, foreign object damage or contamination)
- the importance of ensuring that the completed modification is free from dirt, swarf and foreign object damage
- the methods and equipment used to transport, handle and lift components/looms into position and how to check that the equipment is within its current certification dates
- 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 modification operations and how these can be overcome
- 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 extent of your own responsibility 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 modification activities:
- obtain and use the appropriate documentation (such as job instructions, aircraft modification drawings, wiring diagrams, technical instructions, planning and quality control documentation, aircraft standards and specifications)
- 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
- provide and maintain a safe working environment for the modification activities
- 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 date
- obtain clearance to work on the aircraft, and observe the power isolation and safety procedures
- use safe and approved modification techniques and procedures at all times
- where appropriate, apply electrostatic discharge (ESD) protection procedures
- return all tools and equipment to the correct location on completion of the activities
- dispose of waste items in a safe and environmentally acceptable manner
Carry out modifications to three of the following aircraft avionic systems:
- indication and gauging
- navigational
- infra-red and optical
- pitot static
- armament
- flight guidance and control
- radar
- communication
- electrical power generation and distribution
- passive warning and electronic countermeasure
- internal and external lighting
- ground proximity/obstacle avoidance
- other specific system
Carry out six of the following types of modification:
- replacing cables of different size or length
- adding new looms
- changing or adding components to panels or sub-assemblies
- making changes to looms
- changing the position or angle of breakout points
- changing the position of electrical/avionic units
- making changes to cable terminations
- making changes to structure (such as framework, casings, panels)
- fitting new electrical/avionic systems
- changing the routes of cables
- removing cables
- adding/removing/replacing pitot static pipes
- adding cables
Carry out ten of the following processes:
- soldering and de-soldering
- dismantling and re-assembling
- heat shrinking (devices and boots)
- stage checks of installed components (includes continuity checking)
- crimping (tags and pins)
- electrical bonding
- changing electrical/avionic trays
- updating firmware/software
- repositioning units
- stripping cable insulation
- removal cable protection
- removing and replacing cable end fittings
- adjusting or tuning/calibrating components
- changing components
- repositioning pitot static pipes security devices
Modify avionic systems in compliance 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:
- build records
- log cards
- job cards
- aircraft flight log
- aircraft log book
- other specific recording method
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