Application
This unit of competency requires application of hand skills and the use of system/component knowledge and applicable test equipment to inspect, test and troubleshoot direct current (DC) aircraft electrical systems and components of fixed and rotary wing aircraft that have only DC electrical systems, during scheduled or unscheduled maintenance. Work may be performed individually or as part of a team.
The unit is part of the Avionic Certificate IV (Aircraft Maintenance Stream) training pathway.
The unit is used in workplaces that operate under the airworthiness regulatory systems of the Australian Defence Force (ADF) and the Civil Aviation safety Authority (CASA).
Where a CASA licensing outcome is sought this unit forms part of the CASA requirement for the granting of the chosen maintenance certification licence under Civil Aviation Safety Regulation (CASR) Part 66, in accordance with the licensing provisions in the Companion Volume Implementation Guide.
Elements and Performance Criteria
Elements describe the essential outcomes. | Performance criteria describe the performance needed to demonstrate achievement of the element. | ||
1. | Inspect DC aircraft electrical systems and components | 1.1 | Relevant maintenance documentation and modification status, including system defect reports where relevant, are used to identify specific inspection requirements |
1.2 | Isolation tags are checked and aircraft configured for safe system inspection and operation in accordance with the applicable maintenance manual | ||
1.3 | DC electrical system is visually or physically checked for external signs of defects in accordance with applicable maintenance manual while observing all relevant work health and safety (WHS) requirements | ||
1.4 | Defects are correctly identified and reported | ||
2. | Test/adjust DC aircraft electrical systems | 2.1 | Aircraft and system are prepared in accordance with applicable maintenance manual for the application of power/system operation |
2.2 | Electrical system is functionally tested in accordance with maintenance manual for evidence of serviceability or malfunction | ||
2.3 | System calibration or adjustments are performed in accordance with maintenance manual, as appropriate | ||
3. | Troubleshoot DC aircraft electrical systems | 3.1 | Available information from maintenance documentation and inspection and test results is used, where necessary, to assist in fault determination |
3.2 | Maintenance manual fault diagnosis guides and logic processes are used to ensure efficient and accurate troubleshooting to line replacement level | ||
3.3 | Specialist advice is obtained, where required, to assist with the troubleshooting process | ||
3.4 | System faults are located and the causes of the faults are clearly identified and correctly recorded in maintenance documentation, where required and in accordance with standard enterprise procedures | ||
3.5 | Rectification requirements are determined | ||
Evidence of Performance
Evidence required to demonstrate competency in this unit must be relevant to and satisfy all of the requirements of the elements and performance criteria under the specified conditions of assessment, and must include:
recognition of system and component defects/external damage, correct installation, connection of plugs, terminations, attaching hardware (including cabling/harnesses) and security in:
DC power generation systems, including regulation, distribution and control
battery installations
piston engine ignition and starting systems and components:
magnetos or coils
starter motors
ignition switches/start switches
ignition harnesses
low tension wiring
spark plugs
auxiliary starting devices
gas turbine engine ignition and starting systems (where applicable to the enterprise):
starter motors and starter/generators
high energy ignition units
control units
switches
batteries and associated mounting equipment, including related anti-vibration aids
motors and actuators in DC electrical systems
internal/external lighting systems, including controls
flap systems
landing gear systems
applying logic processes, taking and interpreting electrical measurements, and using test equipment and appropriate wiring diagrams and manuals to isolate malfunctions in the above systems
performing system functional tests and checks to isolate system faults and assess post-maintenance serviceability
applying relevant WHS practices, including those relating to gas turbine engine high energy ignition units.
It is essential that system testing procedures, cleanliness requirements and safety precautions applicable to the electrical system being maintained are fully observed, understood and complied with. Ability to interpret inspection procedures and specifications (allowable limits) and apply them in practice across a range of inspection, testing and troubleshooting applications (including the timely involvement of supervisors or other trades) is critical.
Evidence of transferability of skills and knowledge related to inspection, testing and troubleshooting is essential. This is to be demonstrated through application across a range of aircraft electrical systems and components listed in the Range of Conditions.
Evidence of Knowledge
Evidence required to demonstrate competency in this unit must be relevant to and satisfy all of the requirements of the elements and performance criteria and include knowledge of:
DC circuit theory
electrical system maintenance requirements and troubleshooting procedures
the basic layout (block diagram level), function and operation of:
single generator DC power generation and distribution systems and components, including:
DC generators
alternator/rectifier generators
starter/generators
voltage regulators
circuit protection devices
bus bars
piston engine ignition and starting systems and components, including:
magnetos or coils
starter motors
ignition switches/start switches
ignition harnesses
low tension wiring
spark plugs
auxiliary starting devices
gas turbine igniter and starting systems and components, including specific WHS precautions:
starter motors and starter/generators
high energy ignition units
control units
switches
landing gear and flap systems and components, including:
motors
actuators
selector switches
micro switches
internal and external lighting systems and components
batteries and associated mounting equipment, including related anti-vibration aids
relevant WHS practices
relevant maintenance manuals
relevant regulatory requirements and standard procedures.
Assessment Conditions
Competency should be assessed in the workplace or simulated workplace using tools and equipment specified in the maintenance manuals. It is also expected that general and special purpose tools, test and ground support equipment would be used where appropriate.
The application of testing procedures should clearly indicate knowledge of system operation, the relationship of individual components and the links with other systems (if applicable) within the limits of the aircraft/system fault finding guide before undertaking any action. The work plan should take account of applicable safety and quality requirements in accordance with the industry and regulatory standards.
The following conditions of assessment represent the requirements of the Regulators (ADF and CASA) and maintenance stakeholders and must be rigorously observed.
A person cannot be assessed as competent until it can be demonstrated to the satisfaction of the workplace assessor that the relevant elements and performance criteria of the unit of competency are being achieved under routine supervision on electrical looms, cables and connection hardware, and on each system in the range of conditions and on at least one (1) major component/line replaceable unit (LRU) in each case, as follows:
DC generators and alternator/rectifier generators, and components of related single generator regulation and distribution systems
piston engine ignition and starting system components
specific components of DC electrical systems, such as flaps and landing gear, including related motors and actuators
gas turbine engine igniter and starting systems and components (may be omitted if not applicable to the enterprise)
aircraft lighting
aircraft main batteries (competency may be demonstrated through the performance of a battery check).
This shall be established via the records in the Log of Industrial Experience and Achievement or, where appropriate, an equivalent Industry Evidence Guide (for details refer to the Companion Volume Assessment Guidelines).
Assessors must satisfy the requirements of the National Vocational Education and Training Regulator (Australian Skills Quality Authority, or its successors).
Where the unit is to be used for CASA licensing purposes the Assessor must also meet the criteria specified in the CASR Part 147 Manual of Standards.
Individuals being assessed who have already attained MEA274 Maintain basic light aircraft electrical systems and components will have satisfied the requirements of this unit with regard to common range of conditions variables. The Log of Industrial Experience and Achievement records relating to MEA274 Maintain basic light aircraft electrical systems and components may be accepted as also meeting the evidence requirements for this unit in the applicable common areas.
Foundation Skills
Foundation skills essential to performance are explicit in the performance criteria of this unit of competency.
Range Statement
This field allows for different work environments and conditions that may affect performance. Essential operating conditions that may be present (depending on the work situation, needs of the candidate, accessibility of the item, and local industry and regional contexts) are included. | ||
DC electrical systems/components include: | DC generators and alternator/rectifier generators, and components of related single generator regulation and distribution systems Piston engine ignition and starting system components Specific components of DC electrical systems, such as flaps and landing gear, including related motors and actuators Gas turbine engine igniter and starting systems and components (where applicable to the enterprise) Aircraft lighting Aircraft main batteries | |
Procedures and requirements include: | Industry standard procedures specified by manufacturers, regulatory authorities or the enterprise | |
Sectors
Competency Field
Aviation maintenance