Assessor Resource

MEA281
Maintain light aircraft AC powered instrument systems and components

Assessment tool

Version 1.0
Issue Date: May 2024


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 alternating current (AC) powered aircraft instrument systems, including the power supply, and to remove and install components during scheduled or unscheduled maintenance. Work may be performed individually or as part of a team.

Applications include light fixed wing and rotary wing aircraft with piston or turbine engines.

The unit is part of the small aircraft maintenance Certificate IV (Mechatronics) training pathway.

Where a Civil Aviation Safety Authority (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.

You may want to include more information here about the target group and the purpose of the assessments (eg formative, summative, recognition)



Evidence Required

List the assessment methods to be used and the context and resources required for assessment. Copy and paste the relevant sections from the evidence guide below and then re-write these in plain English.

Elements describe the essential outcomes.

Performance criteria describe the performance needed to demonstrate achievement of the element.

1.

Inspect light aircraft AC instrument systems, power supplies 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

AC instrument system and AC power supply components are 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 light aircraft AC instrument systems, power supplies and components

2.1

Aircraft and system are prepared in accordance with applicable maintenance manual for the application of power/system operation

2.2

Instrument system and AC power supply 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 light aircraft AC instrument systems, power supplies and components

3.1

Available information from maintenance documentation, 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, using test sets, downloaded maintenance data and fault-finding charts or similar, to line replacement level

3.3

Specialist advice is obtained, where required, to assist with the troubleshooting process

3.4

Instrument system or power supply faults are located and the causes of the faults are clearly identified and correctly recorded in maintenance documentation, where required, in accordance with standard enterprise procedures

3.5

Rectification requirements are determined

4.

Remove and install light aircraft AC instrument system, and power supply components

4.1

System is rendered safe and prepared in accordance with the applicable maintenance manual and isolation tags are fitted, where necessary, to ensure personnel safety

4.2

Instrument or power supply component removal is carried out in accordance with the applicable maintenance manual while observing all relevant WHS requirements

4.3

Required maintenance documentation is completed and processed in accordance with standard enterprise procedures

4.4

Removed components are tagged and packaged in accordance with specified procedures

4.5

Instrument or power supply components to be installed are checked to confirm correct part numbers, modification status, serviceability and shelf life

4.6

Physical installation of instrument or power supply components is performed in accordance with the applicable maintenance manual and regulatory requirements, ensuring appropriate adjustment/alignment is carried out

4.7

System is reinstated to correct operational condition in preparation for testing, as necessary

4.8

Required maintenance documentation is completed and processed in accordance with standard enterprise procedures

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 include:

using approved maintenance documentation and aircraft publications relating to AC instrument systems and related AC power supplies

locating and identifying AC powered instrument system components including:

AH, DG, AHRS, servo and encoding altimeters

engine system temperature, speed, oil pressure, torque and manifold pressure

auxiliary systems, including vacuum, fuel storage quantities and fuel flow

remote reading gyro compasses

locating and identifying AC instrument power supply system components, including:

inverters

transformer/rectifier units

voltage and frequency indication

correctly handling and observing maintenance precautions for gyroscopes and gimbals

recognising system and component defects/external damage, correct installation, connection of plugs, terminations, attaching hardware (including cabling/harnesses) and security in AC powered instruments and related power supply, including:

flight instruments

remote reading gyro compasses

piston engine and gas turbine engine indication systems (indicators and transmitters/sensors)

fuel quantity and flow indication systems (indicators, probes and transmitters)

transmitter/indicator measuring instrument systems (pressure, temperature and vacuum)

AC power supply, including inverters and transformer/rectifier units

applying logic processes, taking and interpreting system measurements, 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 WHS requirements relevant to instrument and electrical system maintenance.

It is essential that system testing procedures, cleanliness requirements and safety precautions applicable to the 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 AC powered aircraft instrument systems, AC power supplies and components listed in the Assessment Conditions.

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:

component attachment methods

connection of hardware and plugs

handling precautions for electrostatic sensitive devices

relevant WHS practices

AC theory:

calculations and measurement in AC circuits

inductors and inductive reactance

transformer operation

capacitors and capacitive reactance

LCR circuits and resonance

passive filters

power relationship in reactive circuits

the basic layout (block diagram level), function and operation of AC powered:

flight instruments

remote reading gyro compasses

piston engine and gas turbine engine indication systems (indicators and transmitters/sensors)

fuel quantity and flow indication systems (indicators, probes and transmitters)

transmitter/indicator measuring instrument systems (pressure, temperature and vacuum)

AC power supply including AC generators, inverters and transformer/rectifier units

the operating principles of the above systems and associated with:

atmospheric conditions – properties and effects on aircraft instruments and systems

pressure and temperature sensing elements and their use in aircraft instrument systems

gyroscopes and their use in aircraft instrument systems

electrical fundamentals

relevant maintenance documentation and maintenance publications

maintenance requirements and troubleshooting procedures.

Competency should be assessed in the work environment or simulated work environment using tools and equipment specified in maintenance documentation. It is also expected that applicable general-purpose tools and test equipment found in most routine situations 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 a system and at least one (1) major system component/line replaceable unit (LRU) from each of the following groups:

DG, AH, AHRS and components, servo and encoding altimeters, remote reading gyro compasses and components

piston engine and gas turbine engine indication system components

fuel quantity indication and flow indication systems and components

transmitter/indicator measuring instrument systems (pressure, temperature, vacuum) and components

inverters and transformer/rectifier units.

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.


Submission Requirements

List each assessment task's title, type (eg project, observation/demonstration, essay, assingnment, checklist) and due date here

Assessment task 1: [title]      Due date:

(add new lines for each of the assessment tasks)


Assessment Tasks

Copy and paste from the following data to produce each assessment task. Write these in plain English and spell out how, when and where the task is to be carried out, under what conditions, and what resources are needed. Include guidelines about how well the candidate has to perform a task for it to be judged satisfactory.

Elements describe the essential outcomes.

Performance criteria describe the performance needed to demonstrate achievement of the element.

1.

Inspect light aircraft AC instrument systems, power supplies 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

AC instrument system and AC power supply components are 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 light aircraft AC instrument systems, power supplies and components

2.1

Aircraft and system are prepared in accordance with applicable maintenance manual for the application of power/system operation

2.2

Instrument system and AC power supply 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 light aircraft AC instrument systems, power supplies and components

3.1

Available information from maintenance documentation, 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, using test sets, downloaded maintenance data and fault-finding charts or similar, to line replacement level

3.3

Specialist advice is obtained, where required, to assist with the troubleshooting process

3.4

Instrument system or power supply faults are located and the causes of the faults are clearly identified and correctly recorded in maintenance documentation, where required, in accordance with standard enterprise procedures

3.5

Rectification requirements are determined

4.

Remove and install light aircraft AC instrument system, and power supply components

4.1

System is rendered safe and prepared in accordance with the applicable maintenance manual and isolation tags are fitted, where necessary, to ensure personnel safety

4.2

Instrument or power supply component removal is carried out in accordance with the applicable maintenance manual while observing all relevant WHS requirements

4.3

Required maintenance documentation is completed and processed in accordance with standard enterprise procedures

4.4

Removed components are tagged and packaged in accordance with specified procedures

4.5

Instrument or power supply components to be installed are checked to confirm correct part numbers, modification status, serviceability and shelf life

4.6

Physical installation of instrument or power supply components is performed in accordance with the applicable maintenance manual and regulatory requirements, ensuring appropriate adjustment/alignment is carried out

4.7

System is reinstated to correct operational condition in preparation for testing, as necessary

4.8

Required maintenance documentation is completed and processed in accordance with standard enterprise procedures

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.

AC instrument systems and AC power supply components include:

Directional gyro (DG), artificial horizon (AH), attitude heading and reference system (AHRS) and components, servo and encoding altimeters, and remote reading gyro compasses and components

Piston engine and gas turbine engine indication system components

Fuel quantity indication and flow indication systems and components

Transmitter/indicator measuring instrument systems (pressure, temperature and vacuum) and components

Inverters and transformer/rectifier units

Procedures and requirements include:

Industry standard procedures specified by manufacturers, regulatory authorities or the enterprise

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 include:

using approved maintenance documentation and aircraft publications relating to AC instrument systems and related AC power supplies

locating and identifying AC powered instrument system components including:

AH, DG, AHRS, servo and encoding altimeters

engine system temperature, speed, oil pressure, torque and manifold pressure

auxiliary systems, including vacuum, fuel storage quantities and fuel flow

remote reading gyro compasses

locating and identifying AC instrument power supply system components, including:

inverters

transformer/rectifier units

voltage and frequency indication

correctly handling and observing maintenance precautions for gyroscopes and gimbals

recognising system and component defects/external damage, correct installation, connection of plugs, terminations, attaching hardware (including cabling/harnesses) and security in AC powered instruments and related power supply, including:

flight instruments

remote reading gyro compasses

piston engine and gas turbine engine indication systems (indicators and transmitters/sensors)

fuel quantity and flow indication systems (indicators, probes and transmitters)

transmitter/indicator measuring instrument systems (pressure, temperature and vacuum)

AC power supply, including inverters and transformer/rectifier units

applying logic processes, taking and interpreting system measurements, 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 WHS requirements relevant to instrument and electrical system maintenance.

It is essential that system testing procedures, cleanliness requirements and safety precautions applicable to the 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 AC powered aircraft instrument systems, AC power supplies and components listed in the Assessment Conditions.

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:

component attachment methods

connection of hardware and plugs

handling precautions for electrostatic sensitive devices

relevant WHS practices

AC theory:

calculations and measurement in AC circuits

inductors and inductive reactance

transformer operation

capacitors and capacitive reactance

LCR circuits and resonance

passive filters

power relationship in reactive circuits

the basic layout (block diagram level), function and operation of AC powered:

flight instruments

remote reading gyro compasses

piston engine and gas turbine engine indication systems (indicators and transmitters/sensors)

fuel quantity and flow indication systems (indicators, probes and transmitters)

transmitter/indicator measuring instrument systems (pressure, temperature and vacuum)

AC power supply including AC generators, inverters and transformer/rectifier units

the operating principles of the above systems and associated with:

atmospheric conditions – properties and effects on aircraft instruments and systems

pressure and temperature sensing elements and their use in aircraft instrument systems

gyroscopes and their use in aircraft instrument systems

electrical fundamentals

relevant maintenance documentation and maintenance publications

maintenance requirements and troubleshooting procedures.

Competency should be assessed in the work environment or simulated work environment using tools and equipment specified in maintenance documentation. It is also expected that applicable general-purpose tools and test equipment found in most routine situations 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 a system and at least one (1) major system component/line replaceable unit (LRU) from each of the following groups:

DG, AH, AHRS and components, servo and encoding altimeters, remote reading gyro compasses and components

piston engine and gas turbine engine indication system components

fuel quantity indication and flow indication systems and components

transmitter/indicator measuring instrument systems (pressure, temperature, vacuum) and components

inverters and transformer/rectifier units.

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.

Copy and paste from the following performance criteria to create an observation checklist for each task. When you have finished writing your assessment tool every one of these must have been addressed, preferably several times in a variety of contexts. To ensure this occurs download the assessment matrix for the unit; enter each assessment task as a column header and place check marks against each performance criteria that task addresses.

Observation Checklist

Tasks to be observed according to workplace/college/TAFE policy and procedures, relevant legislation and Codes of Practice Yes No Comments/feedback
Relevant maintenance documentation and modification status, including system defect reports, where relevant, are used to identify specific inspection requirements 
Isolation tags are checked and aircraft configured for safe system inspection and operation in accordance with the applicable maintenance manual 
AC instrument system and AC power supply components are 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 
Defects are correctly identified and reported 
Aircraft and system are prepared in accordance with applicable maintenance manual for the application of power/system operation 
Instrument system and AC power supply is functionally tested in accordance with maintenance manual for evidence of serviceability or malfunction 
System calibration or adjustments are performed in accordance with maintenance manual, as appropriate 
Available information from maintenance documentation, inspection and test results is used, where necessary, to assist in fault determination 
Maintenance manual fault diagnosis guides and logic processes are used to ensure efficient and accurate troubleshooting, using test sets, downloaded maintenance data and fault-finding charts or similar, to line replacement level 
Specialist advice is obtained, where required, to assist with the troubleshooting process 
Instrument system or power supply faults are located and the causes of the faults are clearly identified and correctly recorded in maintenance documentation, where required, in accordance with standard enterprise procedures 
Rectification requirements are determined 
System is rendered safe and prepared in accordance with the applicable maintenance manual and isolation tags are fitted, where necessary, to ensure personnel safety 
Instrument or power supply component removal is carried out in accordance with the applicable maintenance manual while observing all relevant WHS requirements 
Required maintenance documentation is completed and processed in accordance with standard enterprise procedures 
Removed components are tagged and packaged in accordance with specified procedures 
Instrument or power supply components to be installed are checked to confirm correct part numbers, modification status, serviceability and shelf life 
Physical installation of instrument or power supply components is performed in accordance with the applicable maintenance manual and regulatory requirements, ensuring appropriate adjustment/alignment is carried out 
System is reinstated to correct operational condition in preparation for testing, as necessary 

Forms

Assessment Cover Sheet

MEA281 - Maintain light aircraft AC powered instrument systems and components
Assessment task 1: [title]

Student name:

Student ID:

I declare that the assessment tasks submitted for this unit are my own work.

Student signature:

Result: Competent Not yet competent

Feedback to student

 

 

 

 

 

 

 

 

Assessor name:

Signature:

Date:


Assessment Record Sheet

MEA281 - Maintain light aircraft AC powered instrument systems and components

Student name:

Student ID:

Assessment task 1: [title] Result: Competent Not yet competent

(add lines for each task)

Feedback to student:

 

 

 

 

 

 

 

 

Overall assessment result: Competent Not yet competent

Assessor name:

Signature:

Date:

Student signature:

Date: