Overhauling components of aircraft flight guidance and control equipment
Overview
This standard identifies the competences you need to carry out overhauling activities on components of aircraft flight guidance and control equipment, in accordance with approved procedures. The equipment to be overhauled will have been removed from the aircraft and the overhauling activities may take place in a workshop or hangar.
It covers equipment used in both fixed wing and rotary winged aircraft, and covers a range of equipment associated with fly by wire, gyros, autopilot, flight director, angle of attack, turn and slip, and AFCS (Automatic Flying Control System), as applicable to the aircraft types. The overhauling activities will include carrying out all necessary safety checks, dismantling the equipment to unit or component level, inspecting and checking all components for damage and wear, replacing all `lifed' items and worn/faulty components or units, reassembling the equipment and carrying out all necessary tests/checks.
Your responsibilities will require you to comply with organisational policy and procedures for the overhauling activities undertaken and to report any problems with the overhauling activities, or with the tools and equipment used that you cannot personally resolve or that is outside your permitted authority, to the relevant people. You must ensure that all tools, equipment and materials used in the overhauling activities are removed from the work area, 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 overhauling procedures to aircraft flight guidance and control equipment. You will understand the dismantling and reassembly methods and procedures used, and their application. You will know how the equipment functions, the common faults encountered, the purpose of the individual components and associated defects, in adequate depth to provide a sound basis for carrying out the overhauling activities and ensuring that the overhauled equipment meets the required specification.
You will understand the safety precautions required when carrying out the overhauling activities. 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.
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 overhauling schedules to carry out the required work
- establish the components to be removed and where appropriate, mark/label components to aid re-assembly
- carry out the overhaul to the agreed level, using the correct tools and techniques
- ensure that all removed components are correctly identified and stored in the correct location
- replace/refit components using appropriate methods and techniques
- carry out checks on the overhauled equipment using correct procedures
report any instances where the overhauling activities cannot be fully met, or where there are identified defects outside the planned overhauling schedule
complete the relevant documentation, in accordance with organisational requirements
- dispose of unwanted components, waste materials and substances, in accordance with safe working practices and approved procedures
- deal promptly and effectively with problems within your control and report those that cannot be solved
- leave the equipment in a safe and appropriate condition, free from foreign object debris
Knowledge and Understanding
You need to know and understand:
- the safe working practices and procedures and the specific safety precautions to be taken when overhauling aircraft flight guidance and control equipment (to include wearing protective clothing and equipment; lifting and handling techniques; safe working practices and procedures with regard to working on aircraft flight guidance and control equipment; procedures and guidelines which satisfy current regulations such as HASAWA, COSHH and other work related legislation and guidelines)
- the hazards associated with overhauling aircraft flight guidance and control equipment, and with the tools and equipment used, and how to minimise them and reduce any risks
the protective equipment that you need to use for both personal protection (PPE) and protection of the flight guidance and control equipment
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 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
- how to extract and use information from equipment manuals, history/maintenance reports, charts, circuit and physical layouts, specifications, symbols used in aircraft flight guidance and control systems and other documents needed in the overhauling process
- how to carry out currency/issue checks on the specifications you are working with
- terminology used in aircraft flight guidance and control equipment, and the use of system diagrams and associated symbols
- the principles of operation of the aircraft flight guidance and control equipment being overhauled, and the performance characteristics and function of the components within the equipment
- the techniques used to remove components from aircraft flight guidance and control equipment, without damage to the components or surrounding structure (such as de-soldering components, applying electrostatic discharge (ESD) protection procedures)
- the various types of electrical connector that are used, methods of unlocking, orientation indicators, and locating and locking in of the connections
- 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 need to label and store components correctly and to check that replaced components have the correct part/identification markings
- the procedure for obtaining replacement parts, materials and other consumables necessary for the overhaul
- the techniques used to position, align, adjust and secure the replaced components to the equipment, without damage to the components or surrounding structure
- the quality control procedures to be followed during the overhauling 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 and adjustments to ensure the system integrity, accuracy and quality of the overhaul
- the tools and equipment used in the overhauling 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 overhauling activities
- the problems that can occur with the overhauling 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 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 overhauling activities:
- obtain and use the appropriate documentation (such as job instructions, aircraft manuals and overhauling documentation, 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
- provide and maintain safe access and working arrangements for the overhauling area
- 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
- where appropriate, apply electrostatic discharge (ESD) protection procedures
- carry out the overhauling activities, using approved techniques and procedures at all times
- return all tools and equipment to the correct location on completion of the activities
Carry out the overhauling activities to unit level on three of the following types of aircraft flight guidance and control equipment:
- fly by wire
- automatic flying control system (AFCS)
- autopilot
- angle of attack/stall warning
- flight director
- nose wheel steering
- turn and slip indication
- main gear steering
- gyros
Carry out all of the following activities, as applicable to the equipment being overhauled:
- cleaning parts prior to dismantling
- checking components for serviceability
- pre-disassembly checks and tests
- replacing all 'lifed' items (seals, dust caps)
- disconnecting and de-soldering electrical connections
- replacing all damaged or defective components
- reassembling equipment
- removal of earth bonding
- setting and adjusting/calibrating replaced components (such as power output, voltage)
- removal of conformal coating
- removing cable securing devices
- making mechanical connections
- removing bolt securing devices and mechanical fasteners
- soldering electrical connections
- carrying out earth bonding
- dismantling equipment to unit/sub-assembly level
- installing cable securing devices
- dismantling units to component level
- tightening fastenings to the required torque
- marking/labelling of components to aid reassembly
- re-instating conformal coating
- securing components using mechanical fasteners and threaded devices
- applying locking and retaining devices (such as circlips, pins, wire locking)
Carry out overhauling activities to component level on five of the following flight guidance and control equipment components:
- computers
- actuators
- controllers
- transformers
- air data units
- stick position cancellers
- detectors/position sensors
- attitude heading and reference system (AHRS)
- receiver units
- Inertial Reference Unit (IRUs)
- gyros(rate and vertical)
- primary or secondary embedded GPS and INS (EGI)
- trim units
Replace a range of flight guidance and control equipment components, to include eight of the following:
- switches
- instruments/gauges/indicators
- armatures
- relays
- plugs/sockets/terminations
- wires/cables
- gaskets
- batteries
- wiring harness (complete)
- breakers/contacts
- fuses
- fairings/panels
- filament lamps/light emitting diodes
- desiccant
- chassis components
- electronic components (such as resistors, capacitors)
- printed circuit boards
- aerials
- transformers
- screws/bolts/washers
- other specific components
Carry out checks and tests on the overhauled equipment, to include four of the following:
- visual inspection for completeness and freedom
- power output from damage or foreign objects
- continuity checks
- soak test
- standard serviceability test
- bonding tests
- 'special-to-type' tests
- signal injection tests
Overhaul aircraft flight guidance and control equipment in compliance with one of the following:
- Civil Aviation Authority (CAA)/European Aviation Safety Agency (EASA)
- 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 book
- 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