Overhauling components of aircraft pneumatic, vacuum and environmental equipment
Overview
This standard identifies the competences you need to carry out overhauling activities on aircraft pneumatic, vacuum or environmental system equipment and components, 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 both fixed wing and rotary winged aircraft and covers a range of pneumatic, vacuum and environmental system equipment such as emergency blow-down systems; air stairs; sanitary and waste disposal systems; arrestor mechanisms and deck locks; air start systems; weapons systems; flying controls; air driven gyros; cabin pressurisation equipment; air conditioning and heating systems; anti-g; pressurisation of bulkheads, pressure domes, door, canopy and window seals; ice and rain protection; demisting equipment; avionic cooling, and other aircraft specific equipment. The overhauling activities will include carrying out all necessary safety activities, 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 appropriate overhauling procedures to aircraft pneumatic, vacuum and environmental 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, correcting faults 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 components to aid re-assembly
- ensure that any stored energy or substances are released safely and correctly
- 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 pneumatic, vacuum and environmental equipment (to include wearing protective clothing and equipment; lifting and handling techniques; safe working practices and procedures with regard to working on aircraft pneumatic, vacuum and environmental equipment; procedures and guidelines which satisfy current regulations such as HASAWA, COSHH and other work related legislation and guidelines)
- hazards associated with carrying out overhauling activities on aircraft pneumatic, vacuum and environmental equipment (such as releasing stored pressure, misuse of tools, using damaged or badly maintained tools and equipment, not following laid-down overhauling procedures), 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 importance of wearing protective clothing and other appropriate safety equipment (PPE) during the overhaul
- how to extract and use information from aircraft manuals, history/maintenance reports, aircraft logs, charts, circuit and physical layouts, specifications, symbols used in aircraft pneumatic, vacuum and environmental systems and other documents needed in the overhauling process
- how to carry out currency/issue checks on the specifications you are working with
- the procedure for obtaining replacement parts, materials and other consumables necessary for the overhaul
- terminology used in aircraft pneumatic, vacuum and environmental systems, and the use of fluid power diagrams and associated symbols
- the various types of component that make up the aircraft pneumatic, vacuum and environmental equipment (such as pipes; flexible hoses; valves used for pressure, flow and directional control; double and single action cylinders/actuators; pumps; pressure intensifiers, mechanical and electrical control devices)
- the principles of operation of the pneumatic, vacuum and environmental equipment being worked on, and the performance characteristics and function of the valves, cylinders/actuators within the circuit
- the sequence to be adopted for the dismantling/reassembling of various types of pneumatic, vacuum and environmental assemblies
- the techniques used to dismantle the equipment to unit or component level without damage to the components (such as release of pressures/force, proof marking/labelling removed components, extraction of components and the need to protect the circuit integrity by fitting blanking plugs/covers)
- the identification and application of different types of valve, sensor and actuator (such as rotary, linear, mechanical, electrical); cylinders (such as single acting, double acting); pumps (such as positive and non-positive displacement); static and dynamic seals
- the various mechanical fasteners to be removed and replaced, and their method of removal and replacement (such as threaded fasteners, special securing devices)
- methods of lifting, handling and supporting the components during the removal and replacement activities
- recognition of contaminants and the problems they can create; the effects and likely symptoms of contamination in the pneumatic, vacuum and environmental system
- methods of checking that components are fit for purpose, and the uses of inspection/measuring equipment (such as gauges, micrometers, verniers, dial test indicators, mirrors, endoprobes, boroscopes, video probes, scales)
- how to identify defects and wear characteristics, and the need to replace 'lifed' items (such as filters, seals and gaskets)
- how to check that replacement components have the correct part/identification markings
- why electrical bonding is critical and why it must be both mechanically and electrically secure
- how to reassemble the components (such as the use of gaskets and seals, jointing/sealing compounds; ensuring correct tightness of fittings and connections; eliminating stress on pipework/connections; carrying out visual checks of all components; checking security of joints and that the system is safe to re-pressurise)
- why securing devices need to be tightened to the correct torque, locked and labelled, and the different methods that are used
- the tools and equipment used in the overhauling activities and their calibration/care and control procedures
- how to make adjustments to components/assemblies to ensure that they function correctly (such as setting working clearance, setting travel)
- the recording documentation to be completed for the overhauling activities undertaken and where appropriate, the importance of marking and identifying specific pieces of work in relation to the documentation
- the need to control and account for all tools and equipment used during the overhauling activity
the procedure for the safe disposal of waste materials and scrap components
the problems that can occur during the overhauling activity and how they can be overcome
- the extent of your own authority and to whom you should report if you have a problem 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
- ensure the safe depressurisation of the pneumatic or vacuum equipment (where appropriate)
- carry out the overhauling activities, using approved techniques and procedures at all times
- ensure that components and equipment are maintained free from damage and foreign objects
- 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 pneumatic, vacuum or environmental system equipment:
- air driven gyros
- air conditioning
- nose wheel steering
- spoilers
- demisting equipment
- damping mechanisms
- flying controls
- cabin heating and cooling
- emergency blow-down systems
- engine air start
- avionic cooling
- arrester mechanisms
- air intake shutters
- anti-g
- sanitary systems
- wheel braking
- cabin pressurisation
- gun cocking
- air stairs
- pressurised bulkheads
- deck locks
- ice protection
- pressure domes
- weapon bay doors
- rain protection
- waste disposal/utility systems
- fire protection
- galley equipment
- other specific system
Carry out all of the following activities, as applicable to the equipment being overhauled:
- cleaning parts prior to dismantling
- replacing all damaged or defective components
- pre-disassembly checks and tests
- reassembling equipment
- releasing stored energy (where applicable)
- fitting blanks to openings to prevent entry of contaminating debris
- making mechanical connections
- dismantling equipment to unit/sub-assembly level
- setting and adjusting replaced components
- dismantling units to component level
- tightening fastenings to the required torque
- proof-marking/labelling of components
- checking components for serviceability (such as visual, measurement, NDT, use of probes/scopes)
- replacing all 'lifed' items (such as piston seals, dust caps, filters, gaskets)
- securing components using mechanical fasteners and threaded devices
- applying locking and retaining devices (such as circlips, pins, wire locking, lock nuts, stiff nuts, swage nuts)
Carry out overhauling activities to component level on three of the following pneumatic, vacuum or environmental system components:
- air pumps
- pressure intensifiers
- air reservoirs/tanks
- vacuum pumps
- accumulators
- cold air units/air cycle machines
- water pumps
- compressors
- air-conditioning packs
- motors
- control valves
- cylinders/actuating mechanisms
- air coolers
- regulators
- safety devices
- water extractors
- pressure controllers
- heat exchangers
- toilet flushing equipment
- humidifier
- galley equipment
- other specific components
Replace a range of pneumatic, vacuum or environmental equipment components, to include eight of the following:
- pipes, ducting and hoses
- housings
- spring mechanisms
- unions and couplings pistons
- plungers
- gauges
- strainers including water separator
- bearings
- gaskets
- non-return valves
- rollers
- sealing devices
- actuating mechanisms
- regulators
- electrical controls (solenoids, motors, switches)
- pressure reducing valves
- air filters
- diaphragms
- sensors
- door, window and canopy seals
- other specific components
Carry out checks and tests on the overhauled equipment, to include three of the following:
- leak test
- range of movement
- functional test
- standard serviceability test
- pressure test
- 'special-to-type' tests
- range of movement/extension
- timings/sequencing
Overhaul aircraft pneumatic, vacuum or environmental 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