Maintaining water and waste systems on aircraft
Overview
This standard identifies the competences you need to carry out maintenance activities on aircraft water and waste systems, in accordance with the aircraft maintenance manual, approved change documentation (service bulletin) and airworthiness requirements. It covers both fixed wing and rotary winged aircraft, and covers the units and components which store and deliver for use, fresh water and those fixed components which store and provide a means of removing water and waste. The maintenance activities will include the removal, fitting and testing of a range of water and waste system components, such as wash basins, toilet assemblies, water and waste tanks, valves and pipes. You will be expected to use the approved procedure for correctly isolating the system before breaking into the system circuit. You will remove the required components and fit approved replacements, as appropriate. You will then need to test and adjust the completed system to meet the aircraft maintenance manual, change documentation (service bulletin) and airworthiness requirements.
Your responsibilities will require you to comply with the specific practices and procedures identified in the aircraft manual, change/service bulletin documentation and airworthiness requirements for the maintenance 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 thoroughly, 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 maintenance techniques and procedures to aircraft water and waste systems. You will understand the removal, fitting and testing methods and procedures, and their application, along with the water and waste systems 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 maintenance activities, correcting faults and for ensuring that the equipment is maintained to the required standard.
You will understand the safety precautions required when working on aircraft water and waste systems, especially those involved with working on pressurised systems. 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:
- This standard is designed to cover the practical experience requirements of the Airline Transport Association (ATA) Chapter 38 Water and Waste.
- To display competence in this standard, it is necessary to both remove and fit aircraft water and waste system components. You must remove components; however, you may fit a replacement component where the original was previously removed by another person. You should also be aware of how to leave a system in a safe condition if maintenance tasks cannot be completed. This covers both the physical systems and the job documentation.
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 maintenance schedules to carry out the required work
- carry out the maintenance activities within the limits of your personal authority
- carry out the maintenance activities, and replace components in the specified sequence and in an agreed timescale
- report any instances where the maintenance activities cannot be fully met or where there are identified defects outside the planned schedule
- complete relevant documentation in accordance with organisational requirements
- dispose of waste materials in accordance with safe working practices and approved procedures
- leave the aircraft and 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 on aircraft water and waste systems (including any specific legislation, regulations/codes of practice for the activities, equipment or materials)
- the importance of maintenance on aircraft waste and water systems, and impact upon (Extended Range Twin-Engine Operations Procedures) ETOPS systems, Electrical Wiring Interconnect Systems (EWIS), legislation and local procedures
- the need to check that cabin/cockpit switches, selectors and circuit breakers are in the correct position before applying any form of external power (such as electrical, hydraulic, air or vacuum)
- 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 hazards associated with carrying out maintenance activities on aircraft water and waste systems, and with the tools and equipment used, and how to minimise them and reduce any risk
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)
the importance of aircraft husbandry and of ensuring that, throughout the maintenance activity, the aircraft and work area are maintained free from foreign objects, and the implications of FOD to the safety of the aircraft
- how to extract and use information from aircraft manuals, log books, flight logs, charts, circuit and physical layouts, specifications, symbols used in aircraft water and waste systems, and other documents needed in the maintenance activities
- how to carry out currency/issue checks on the specifications you are working with
- terminology used in aircraft water and waste systems, and the use of system diagrams and associated symbols
- the various types of pipe and component that make up the aircraft water and waste system (such as pipes; pumps; valves; water heaters; taps; toilet units; mechanical and electrical control devices)
- why electrical bonding is critical, and why it must be both mechanically and electrically secure
- 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 principles of operation of the water and waste system being worked on, and the function of the various units that make up the system
- the techniques used to remove components from aircraft water and waste systems without damage to the components or surrounding structure (such as release of fluids, removal of components and the need to protect the circuit integrity by fitting blanking plugs and labelling exposed circuits)
- the various mechanical fasteners to be removed and replaced, and their methods of removal and replacement (such as threaded fasteners, special securing devices)
- the various types of electrical connector that are used, methods of unlocking, orientation indicators and locating and locking-in of the connections
- the need to label and store correctly components that require repair or overhaul, and to check that replacement components have the correct part/identification markings and accompanying release documentation
- how to fit components into the system (such as ensuring the correct tightness of fastenings, fittings and pump connections; eliminating stress on pipework/connections; correctly making electrical connections; carrying out visual checks of all components)
- how to make adjustments to components/assemblies to ensure that they function correctly (such as flow settings, travel and working clearance)
- why securing devices need to be tightened to the correct torque, locked and labelled, and the different methods that are used
- how to carry out routine checks and servicing of the aircraft water and waste system (including checking for leaks, checking and changing filters)
- the types of test to be carried out on the aircraft water and waste system, and the test equipment to be used
- the methods and procedures to be used to carry out the various tests on the water and waste system
- the importance of carrying out the tests in the specified sequence, checking all readings and movements at each stage
- how to record the results of each individual test and the documentation that must be used
- how to analyse the test results and how to make valid decisions about the acceptability of the aircraft water and waste system
- the procedures to be followed if the equipment or system fails to meet the test specification
- 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 maintenance of the aircraft water and waste system:
- ensure that appropriate authorisation to work on the aircraft is obtained, and observe all relevant isolation and safety procedures
- obtain and use the correct documentation (such as job instructions, technical instructions, aircraft manuals and maintenance documentation)
- 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 dates
- 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 system is safely isolated and depressurised and (where appropriate) drain off fluid before breaking into the system
- ensure that the relevant safety devices and mechanical/physical locks are in place (where appropriate)
- use approved removal, fitting and testing techniques and procedures at all times
- return tools and equipment to the correct storage location on completion of the activities
- ensure that work carried out is correctly documented and recorded
- ensure that any outstanding tests are correctly documented
Carry out maintenance on two of the following parts of the aircraft water and waste systems:
- potable (drinking water)
- wash
- waste disposal
- air supply
Remove and fit four different aircraft water and waste system components (at least two must be from group A):
Group A:
1. water pump
2. fresh water tanks
3. water heaters
4. toilet pump
5. waste water tanks
6. electrical elements
7. valves
8. toilet assemblies
9. taps
10. water pressure regulator
11. flushing systems
12. wash basins
13. solenoids
Group B:
14. sensors/transmitters
15. water filters
16. temperature probes
17. drains/traps
18. water pipes and hoses
19. portable toilet
20. wiring/switches/plugs
21. other specific components
Carry out fifteen of the following maintenance activities:
- removing access panels and covers to expose components to be removed
- carrying out fault diagnosis and system checks
- preparing the system for maintenance (such as isolating, draining)
- disconnecting electrical connections
- replacing single use items (such as seals, gaskets)
- removal of bonding
- refitting components in the correct position, orientation and alignment
- disconnecting/removing hoses and pipes
- removing mechanical fasteners and securing devices
- setting and adjusting replaced components
- making mechanical connections
- supporting equipment to be removed
- making electrical connections
- dismantling equipment to an appropriate level
- carrying out bonding
- covering (protecting) exposed components, wires, pipework or vents
- torque loading
- carrying out system functional checks
- checking components for serviceability
- replacing damaged/defective components
- ensuring that replacement components have the correct part numbers
- fitting blanks, 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)
Service/check aircraft water and waste systems, to include carrying out all of the following:
- checking system for leaks
- replacing water filters
- checking and adjusting supply water pressure
- checking tank content indicating systems
Carry out three of the following tests on the aircraft water and waste systems:
- leak test
- reduced system test
- pressure test
- built in test equipment (BITE) test
- system charging
- 'special-to-type' tests
Using one of the following:
7. aircraft power source/pumps
8. ground test rig
Complete the relevant paperwork, to include one from the following and pass it to the appropriate people:
- job cards/work sheets
- computer records
- aircraft technical log
- aircraft cabin log
- aircraft log book
Carry out maintenance on aircraft water and waste system components in compliance with one of the following:
- Civil Aviation Authority (CAA)/European Aviation Safety Agency (EASA)
- Extended Range Twin-Engine Operations Procedures (ETOPS) (where appropriate)
- Ministry of Defence (MoD)
- Military Aviation Authority (MAA)
- Aerospace Quality Management Standards (AS)
- Federal Aviation Authority (FAA)
- aircraft maintenance manual/approved change documentation (service bulletin)
- manufacturers standards and procedures
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