Removing and replacing aircraft power plant and components
Overview
This standard identifies the competences you need to carry out the removal and replacement of a complete engine exchange unit and the removal and replacement of components of aircraft power plant, in accordance with approved procedures. It covers both fixed wing and rotary winged aircraft and includes a range of power plant such as turbo prop, turbo jet, by-pass, ducted fan, turbo shaft, piston engines and auxiliary power units (APU) or ground turbine start (GTS units).
The removal and replacement activities will include taking all necessary safeguards to isolate the system, support and lift removed and replaced parts, replacing faulty equipment at component or unit level, replenishing fluids, setting and adjusting replaced components and leaving the power plant 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 to aircraft power plant. You will understand the removal and replacement methods and procedures, and their application, along with the power plant maintenance requirements. You will know how the power plant 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.
You will understand the safety precautions required when working on aircraft power plant, especially those for isolating the equipment. 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.
Notes To display competence in this standard it is necessary to both remove and replace components from aircraft power plant. 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
- ensure that any stored energy or substances are released safely and correctly
- 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 or overhaul
- dispose of waste materials and scrap components, in accordance with safe working practices and approved procedures
- leave the aircraft and the power plant in a safe and appropriate condition, free from foreign object debris and in a condition ready for testing
Knowledge and Understanding
You need to know and understand:
- the specific safety practices and procedures that you need to observe when working on aircraft power plant (including any specific legislation, regulations/codes of practice for the activities, equipment or materials)
- the importance of maintenance on and impact upon (extended twin operations procedures) ETOpS systems, legislation and local procedures
- hazards associated with removing and replacing aircraft power plant components, and with the tools and equipment used (such as handling oils, greases, aviation fuel, stored pressure/force, misuse of tools, using damaged or badly maintained tools and equipment, not following laid-down maintenance 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 protective equipment that you need to use for both personal protection (PPE) and protection of the aircraft
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)
how to extract and use information from aircraft maintenance manuals, history/maintenance reports, flight logs and other documents needed in the removal and replacement process
- how to carry out currency/issue checks on the specifications you are working with
- terminology used in aircraft power plant systems
- the principles of how the equipment functions, its operating sequence, the working purpose of individual units/components and how they interact
- the techniques used to remove components from aircraft power plant without damage to the components or surrounding structure (such as release of pressures/force, draining of fluids, proof marking, extraction of components), and the need to protect the system integrity by fitting blanking plugs and ensuring that exposed components are correctly covered/protected
- the importance of applying electrostatic discharge (ESD) procedures when working on sensitive equipment or devices
- the various mechanical fasteners that will need to be removed and replaced and their method of removal and replacement (such as threaded fasteners, special securing devices)
- the various types of electrical connectors that are used, methods of unlocking, orientation indicators and locating and locking in of the connections
- methods of lifting, handling and supporting the components/equipment during the removal and replacement activities
- the identification and application, fitting and removal of different types of bearings (such as roller, ball, thrust)
- methods of checking that components are fit for purpose and how to identify defects and wear characteristics
- the uses of measuring equipment (such as micrometers, Verniers, expansion indicators and other measuring devices)
- the need to replace 'lifed' items (such as seals and gaskets)
- the need to correctly label and store components that require repair or overhaul and the importance of checking that replacement components have the correct part/identification markings
- how to replace and re-connect components into the system (such as the use of gaskets/seals and jointing/sealing compounds; ensuring correct orientation, position and alignment; tightening securing devices to the required torque; replacing locking and securing devices; eliminating stress on pipework/connections; ensuring that pipework and cables are correctly supported at suitable intervals; carrying out visual checks of all components)
- how to make adjustments to components/assemblies to ensure that they function correctly (such as balancing of rotating components, setting working clearance, setting travel, setting backlash in gears, preloading bearings)
- why securing devices need to be tightened to the correct torque, locked and labelled, and the different methods that are used
- why electrical bonding is critical and why it must be both mechanically and electrically secure
- the importance of making 'off-load' checks before running the equipment under power
- how to check that tools and equipment are free from damage or defect, are in a safe, tested and usable condition and are configured correctly for the intended purpose
- 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
- how to use lifting and handling equipment in the maintenance activity
- 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, scrap components, oils and fluids
- the problems associated with removing and replacing power plant components 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 removal and replacement activity:
- obtain clearance to work on the aircraft, and observe all relevant 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 the safe isolation of the power plant before carrying out work on the equipment
- 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
- return all tools and equipment to the correct location on completion of the activities
Remove and replace one of the following types of aircraft power plant assembly:
- turbo prop
- turbo-shaft
- auxiliary power unit (APU)
- ducted fan
- turbo-fan
- ground turbine start (GTS)
- turbo jet
- piston
Remove and replace components from each of the following groups: Major engine components: Remove and replace one of the following:
- air intake
- starter motor
- turbochargers
- exhaust unit
- gearbox ancillaries
- pumps (fuel, oil)
- propellers
- coolers (air, oil, fuel)
- cylinder heads
- gear box
- heat exchangers (oil, fuel)
- valve mechanisms
- reverse thrusters
- torque converters
- magneto
- fuel control unit
- superchargers
- constant pitch and speed units
Other engine components: Remove and replace two of the following:
19. filters (fuel, oil, air)
20. levers and linkages
21. fire detection units
22. pipes and hoses
23. damper/connector arm
24. fire wire
25. igniters
26. spark plugs
27. magnetic chip detectors
28. sensors
29. fire bottle
30. other specific components
Carry out all of the following removal and replacement activities:
- disconnecting electrical connections
- positioning and aligning replaced components
- disconnect/removing hoses and pipes
- setting and adjusting replaced components
- supporting equipment to be removed
- making mechanical connections
- dismantling equipment to an appropriate level
- making electrical connections
- proof marking components to aid reassembly
- tightening fastenings to the required torque
- applying and removing covering/protection to exposed components, wires, pipework or vents
- making `off-load' checks before starting up
- replenishing fluids, oils and greases
- checking components for serviceability
- use of ground support equipment
- replacing all damaged/defective components
- using lifting operations (manual or automated)
- applying gaskets and sealant/adhesives
- securing components using mechanical fasteners and threaded devices
- applying bolt locking methods (such as split pins, wire locking, lock nuts)
- labelling (and storing in the correct location) components that require repair or overhaul
- protecting and preparing removed components for transportation for overhaul
Remove and replace aircraft power plant and components 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:
- job cards
- computer records
- aircraft service/flight log
- aircraft log books
- 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