Unit of competency details

Unit descriptor 

This unit of competency is part of the Mechanical Certificate IV AME training pathway. It covers the competencies required to maintain installed aircraft two stroke petrol engines. Where a CASA licensing outcome is sought this unit forms part of the CASA requirement for the granting of the chosen Aircraft Maintenance Engineer Licence under CASR Part 66, in accordance with the licensing provisions in Section 3, Assessment Guidelines.

Application of the unit 

This unit requires application of hand skills, the use of maintenance publications and knowledge of two stroke petrol engine and system theory to inspect, test and troubleshoot, remove and install aircraft two stroke petrol engines and engine system components.

Applications include aircraft two stroke petrol engines driving fixed pitch propellers. Where the engine is driving a constant speed propeller, MEA307B Remove and install propeller systems and components and MEA315B Inspect, test and troubleshoot propeller systems and components, will also be required.

Prerequisite units 

Employability skills 

This unit contains employability skills.

Elements describe the essential outcomes of a unit of competency.

Performance criteria describe the performance needed to demonstrate achievement of the element. Where bold italicised text is used, further information is detailed in the required skills and knowledge section and the range statement. Assessment of performance is to be consistent with the evidence guide.

ELEMENT 

PERFORMANCE CRITERIA 

1. Inspect two stroke petrol engine and components/systems

1.1. Isolation tags already attached to the system or related systems are checked and aircraft/engine configured for safe system inspection and operation in accordance with applicable maintenance manual

1.2. Two stroke petrol engine and components /systems  are visually or physically checked for external and internal signs of defects in accordance with applicable maintenance manual

2. Test two stroke petrol engines

2.1. Aircraft and engine are correctly prepared in accordance with applicable maintenance manual

2.2. Assistance is provided with engine and/or system operation during prescribed test procedures to establish serviceability and correct function in accordance with applicable maintenance manual

3. Troubleshoot two stroke petrol engines

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 guide and logical processes are used to ensure efficient and accurate troubleshooting 

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

3.4. Two stroke petrol engine faults are located and the causes of the faults are clearly identified and correctly recorded in maintenance documentation, where required

3.5. Fault rectification requirements are determined to assist in planning the repair

4. Remove two stroke petrol engine and engine system components

4.1. Aircraft is prepared and supported and rendered safe in accordance with the applicable maintenance manual and isolation tags are fitted, where necessary, to ensure the safety of personnel and freedom from damage during engine removal

4.2. Removal is carried out in accordance with the applicable maintenance manual

4.3. Engine is tagged and prepared for transport or storage in accordance with the specified procedures

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

5. Install two stroke petrol engine and engine system components

5.1. Engine to be installed is checked to confirm correct part or model numbers, modification status and serviceability

5.2. Installation is carried out in accordance with the applicable maintenance manual

5.3. Support/safety equipment is removed at the appropriate time to ensure personnel safety and freedom from structural damage

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

REQUIRED SKILLS AND KNOWLEDGE 

This section describes the skills and knowledge required for this unit.

Required skills 

Look for evidence that confirms skills in:

• applying relevant occupational health and safety (OHS) procedures
• using relevant maintenance documentation and aircraft manuals
• recognising external and internal signs of defects in two stroke petrol aircraft engines, components and system components through visual/physical inspection
• assisting with testing of two stroke petrol engine and engine system operation, be able to operate systems, monitor indications, record parameters and recognise correct function
• compiling engine condition monitoring records
• rigging and adjusting engine controls and systems
• using fault diagnosis guides and equivalent data to accurately and efficiently troubleshoot the causes of unserviceabilities in two stroke petrol engines and engine systems, clearly record details and identify the required rectification actions
• correctly removing and installing two stroke petrol engine and engine components

Required knowledge 

Look for evidence that confirms knowledge of:

• OHS procedures associated with engine maintenance, including lifting and handling of heavy objects
• fault diagnosis techniques
• two stroke petrol aircraft engine layout and operation:

• principles of operation of two stroke engines
• component function, construction and materials
• engine operation
• engine power, efficiency and performance

• two stroke aircraft engine fuels, oils and fuel/oil mixing
• components, layout and operation of two stroke petrol aircraft engine:

• fuel systems
• ignition systems:

• magneto
• coil
• spark plugs
• ignition harnesses
• switches

• starting systems
• induction systems
• cooling systems (liquid and air)
• exhaust systems
• electrical and instrument system interfaces:

• battery charging system
• tachometer

• removal and installation procedures for two stroke petrol aircraft engines and engine components
• petrol two stroke aircraft engine maintenance requirements and troubleshooting
• relevant maintenance manuals
• relevant regulatory requirements and standard procedures

EVIDENCE GUIDE 

The Evidence Guide provides advice on assessment and must be read in conjunction with the performance criteria, required skills and knowledge, range statement and the Assessment Guidelines for the Training Package.

Overview of assessment 

A person who demonstrates competency in this unit must be able to apply hand skills, use maintenance publications and engine and system theory knowledge to inspect, test, troubleshoot, remove and install aircraft two stroke petrol engines and engine system components while applying all relevant safety precautions.

Critical aspects for assessment and evidence required to demonstrate competency in this unit 

The underlying skills inherent in this unit should be transferable across a range of inspection, testing, troubleshooting and removal and installation tasks (including the timely involvement of supervisor or other trades) associated with two stroke petrol aircraft engines and engine. It is essential that system testing procedures take into account all safety precautions associated with two stroke petrol engine system operation and that awareness be demonstrated of dual inspection requirements associated with work on engine controls.

Evidence of transferability of skills and knowledge related to inspection, testing and troubleshooting is essential. This may be demonstrated through application across a number of engine systems or types. Ability to interpret inspection procedures and specifications (allowable limits) and apply them in practice is critical. The application of testing procedures and functional checks should also indicate knowledge of system operation. Engine system operation knowledge, the relationship of individual components and the links with other systems will be necessary to supplement evidence of ability to carry out engine control system checks and troubleshoot the system 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.

A person cannot be assessed as competent until it can be demonstrated to the satisfaction of the workplace assessor that the relevant elements of the unit of competency are being achieved under routine supervision on at least one item from each of Groups 1 to 7 listed in the Range Statement. This shall be established via the records in the Log of Industrial Experience and Achievement or, where appropriate, an equivalent Industry .

Context of and specific resources for assessment 

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 general purpose tools and test equipment found in most routine situations would be used where appropriate.

Method of assessment 

Guidance information for assessment 

RANGE STATEMENT 

The range statement relates to the unit of competency as a whole. It allows for different work environments and situations that may affect performance. Bold italicised wording, if used in the performance criteria, is detailed below. Essential operating conditions that may be present with training and assessment (depending on the work situation, needs of the candidate, accessibility of the item, and local industry and regional contexts) may also be included.

Note 

Range statements listed below are numbered to facilitate specification of the assessment requirements included in the Evidence Guide

Two stroke engines and components /systems 

Two stroke petrol engines and components/systems may include:

1. Two stroke petrol aircraft engines, main components, including reduction gearboxes and accessories/drives

2. Ignition system

3. Control system

4. Starter system

5. Fuel, air systems

6. Cooling system (liquid or air as applicable to enterprise)

7. Exhaust system

Testing of engines 

Testing of engines fitted to helicopters (where auxiliary drive is not available) may be carried out through the applicant directing a pilot qualified on type

Troubleshooting 

Troubleshooting involves the use of test sets, downloaded maintenance data and fault-finding charts or similar, to line replacement level

Application 

Application of this unit may relate to:

• scheduled or unscheduled maintenance
• individual or team-related activities

Procedures and requirements 

Refer to industry standard procedures specified by manufacturers, regulatory authorities or the enterprise

Unit sector 

Competency field 

Aviation maintenance

Co-requisite units 

MEA353A

Maintain basic light aircraft engines and propellers