Testing aircraft hydraulic systems
Overview
This standard identifies the competences you need to test aircraft hydraulic systems, in accordance with approved procedures. It covers both fixed wing and rotary winged aircraft. You will be required to test aircraft hydraulic systems, including landing gear, flying controls, flaps, nose wheel steering, rotor brakes, slats, deck locks and arrester mechanisms. You will be required to select the appropriate tools and equipment to use, based on the operations to be performed and the systems to be tested.
Your responsibilities will require you to comply with organisational policy and procedures for the aircraft hydraulic system tests and to report any problems with the testing activities 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 and instruction, 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 aircraft hydraulic test procedures. You will understand the aircraft hydraulic system under test, and its application, and will know about the testing requirements, in adequate depth to provide a sound basis for carrying out the activities, correcting faults and ensuring that the tested system functions to the required specification.
You will understand the safety precautions required when carrying out the testing activities. You will be required to demonstrate safe working practices throughout and will understand the responsibility you owe to 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 appropriate procedures for use of tools and equipment to carry out the required tests
- set up and carry out the tests using the correct procedures and within agreed timescales
- record the results of the tests in the appropriate format
- review the results and carry out further tests if necessary
- leave the aircraft and work area 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 testing hydraulic systems (including any specific legislation, regulations/codes of practice for the activities, equipment or materials)
- the health and safety requirements of the work area where you are carrying out the activities and the responsibility these requirements place on you
- the safety procedures that must be carried out before work is started on the aircraft
- the protective clothing and equipment (PPE) to be worn and where it can be obtained
- hazards associated with testing aircraft hydraulic systems (such as handling hydraulic fluids, working on pressurised systems, traps from moving parts) and with the tools, materials and equipment used, and how to minimise them and reduce any risks
- the correct operating procedures of the system being tested
- electrical bonding specifications and their importance
- how to obtain the required test schedules and specifications for the aircraft and system being tested and how to check their currency and validity
- how to read and interpret the specifications and from whom you can seek assistance if you have problems or issues regarding the test schedules or specifications
- the methods and procedures to be used to carry out the various tests on the hydraulic systems
- test equipment to be used and its selection for particular tests; calibration of test equipment (where applicable) and the currency/issue checks to be done
- 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 techniques, methods and procedures to be used during the tests
- the need to apply test pressures in incremental stages and to check all readings and pressures at each stage
- the fault finding techniques to be used if the system fails the tests
- how to record the results of each individual test and the documentation that must be used
- from whom to seek authorisation if you need to alter or change the test procedures
- how to analyse the test results and how to make valid decisions about the acceptability of the aircraft
- problems that can occur with the testing activities and how they can be overcome
- the items that may cause errors or discrepancies in/with the test results and how to avoid these
- any required environmental controls relating to the testing
- the documentation to be completed at the end of the testing activities
- 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 testing of the hydraulic system:
- obtain and use the appropriate documentation (such as job instructions, aircraft hydraulic system test procedures, quality control documentation, history sheets, flight logbook, 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 testing 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 all relevant safety procedures
- ensure that isolation procedures are followed and that safe working distance procedures are set up
- carry out the tests, using the specified techniques and procedures
- return all tools and equipment to the correct location on completion of the testing activities
Test two of the following aircraft hydraulic systems:
- landing gear
- flying controls
- slats
- nose wheel steering
- flaps
- arrestor mechanisms
- wheel braking system
- rotor brakes
- deck locks
- other specific system
Test aircraft hydraulic systems, using tools or test equipment which include three from the following:
- hydraulic pumps
- flushing blocks
- blanking equipment
- pressure devices
- flushing pipes
- connecting equipment
- hydraulic testing rigs
- bleeding equipment
- sampling devices
Carry out all of the following types of test:
- return line pressure test
- reduced system flush
- fluid sampling/taking results
- pressure line pressure test
- system flush
- leak test
- functional test
Deal with two the following complexities during the testing activities:
- equipment with no faults
- equipment with faults
- equipment with intermittent faults
Use two of the following fault finding techniques:
- six point
- input-to-output
- equipment self-diagnostics
- half-split
- function testing
- emergent problem sequence
- injection and sampling
- unit substitution
Review and record fault symptoms and history of problems using four of the following:
- data sheets
- log cards/history sheet
- fault records
- calibration records
- aircraft documentation
- maintenance records
- other specific records
Carry out tests in compliance with one of the following standards:
- Civil Aviation Authority (CAA)/European Aviation Safety Agency (EASA)
- Ministry of Defence (MoD)
- Military Aviation Authority (MAA)
- Aerospace Quality Management Standards (AS)
- customer standards and requirements
- Federal Aviation Authority (FAA)
- company standards and procedures
- BS, ISO or BSEN standards and procedures
- specific equipment requirements
- 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