Requirements for Approved Maintenance Organisations (Part 145)

This page provides further detail for those either applying to become an Approved Maintenance Organisation (AMO) or who are already approved under Part 145 of the Civil Aviation Safety Regulations (CASR).

Demonstrating your capabilities

It is vital that your organisation is fully prepared for, and capable of providing, the scope of maintenance work that you apply for or have been approved to provide.

The purpose of this guidance is to remove ambiguity about what we expect of an organisation applying for Part 145 approval or wishing to maintain a Part 145 approval.

The following sections outline our expectations and are based on the Part 145 Manual of Standards (MOS).

Use of the Sample exposition for Part 145 of CASR document and associated Acceptable means of compliance and guidance material (AMC-GM) for Part 145 will assist you to create or update your Maintenance Organisation Exposition (MOE).

Facility requirements (MOS section 145.A.25)

You must have facilities appropriate for the scope of work you are approved to provide.

Line Maintenance providers are expected to have office accommodation, storage facilities and, for larger providers, possibly a workshop subject to the extent of activities. To ensure personnel from the organisation are appropriately supported, typically facilities will be within a reasonable distance from the airside area activities.

Base maintenance providers must have a hangar which accommodates the aircraft types for which they are approved to maintain with offices, storage facilities and workshops as required.

The aircraft type must be able to be completely enclosed by the facility. It is not acceptable for the aircraft tail to be outside the hangar while performing base maintenance. Work may be performed outside the hangar subject to procedures being approved in the organisation’s exposition.

Certifying personnel and manpower resources (MOE sections 145.A.30 and 145.A.35)

You must have sufficient staff to plan, perform, supervise, inspect and monitor the quality of activities which you are approved to perform.

This must be supported with a manpower plan which shows either:

  • planned vs actual man-hours for work which is scheduled and has been completed at the organisation; or
  • provides a capacity projection based on number of staff available and envisaged scope of work, including the assumptions made to develop the plan (such as number of staff needed to complete a check; or number of persons to run a roster at a line station; typical level of defects and scheduled maintenance workload for a night stopping aircraft). This can then be used to establish the maximum capacity and scope of work you can undertake.

The manpower plan must take into consideration:

  • Training, leave and an allowance for sickness etc.
  • Declaring a realistic efficiency level – it is not feasible to be 100% efficient. Human performance principles suggest that a figure of 80% or less is more realistic when taking account of human factors.
  • Resilience within the organisation. It is not possible to hold an approval based on one person's licence for aircraft where an A1 rating is required. The Acceptable means of compliance and guidance material (AMC-GM) for Part 145 explains at section 145.A.10 the limitations and permissible arrangements for organisations maintaining small aircraft and aeronautical products.
  • Your ability to maintain compliance, even when some staff are not available. This ensures an aircraft's maintenance is not compromised or halted due to sickness or other non-availability of staff.
    The MOS section 145.A.30 requires you to have appropriate aircraft type rated certifying staff qualified as Category C licence holders, supported by sufficient aircraft type rated staff qualified as Category B licence holders. The certifying staff must be appropriately qualified as specified by paragraph 145.A.30(k) of the MOS, which includes requirements to hold an Australian Part 66 Aircraft Engineer Licence for the aircraft/engine combination or rating in the licence category applicable to the maintenance authorisation.

Maintenance data (MOE section 145.A.45)

Generic Maintenance data for each aircraft type within the requested or approved scope of work must always be available at the organisation.

This data should be used in the initial approval stages to define your tooling requirements and assist in the creation of the manpower plan. It will define manpower requirements for each task. It will also need to be available during our future audits to demonstrate your overall capability to perform maintenance.

You must identify if your data will be supplemented with customer supplied data specific to a particular model/fleet. Where customer supplied data is not used, you must have a subscription service in place prior to commencement of any work.

You must have procedures in place that demonstrate how you control the data and ensure that it is up to date before use.

It is not acceptable for data to be supplied solely by the customer directly prior to an aircraft input. This will not allow appropriate production planning to take place prior to any work being performed.

Tools, equipment and material (MOE section 145.A.40)

You must have all tooling required to complete the maintenance tasks within your scope of work permanently available at your facilities. The exception to this requirement is where a task is only performed infrequently (as a guide, tasks that are performed at one in three of similar inputs). In these cases, you can acquire the tooling at the time the task is performed (through loan or pool arrangements).

It is acceptable for appropriate tooling for the scope of work to be supplied to you through a contract with an organisation that supplies, maintains and updates/replaces the tooling held. The tooling should be provided on a permanent basis and its availability should not be dependent on a contract with an operator. It remains your responsibility to determine that the tooling is of the correct type and is in a condition that is suitable for use.

You must ensure you have sufficient staging and access equipment to gain access to all areas of the aircraft that fall within your approved scope of work. Access equipment or staging should be of a suitable type to allow the maintenance task to be performed in an effective manner. Staging and access equipment should provide a stable working area where tools and materials can be located while performing the task to ensure that potential Human Factors issues are minimised.

All tooling and equipment must be controlled through a register and maintained or calibrated to Original Equipment Manufacturer requirements/national standards. This includes servicing of Aircraft Jacks, Staging and Access Equipment.

You may only use alternative or locally fabricated tools if you have an approved procedure in your Exposition. This is so we can ensure an assessment of the suitability of alternative tooling has been carried out, and that the use of the alternative tool has been properly validated. Any such tools must be of an equivalent specification, standard and accuracy as those specified in the applicable maintenance data provided by the Original Equipment Manufacturer.

Maintenance Organisation Exposition (MOE section 145.A.70)

Your Maintenance Organisation Exposition is integral to your ability to demonstrate your capability and compliance with Part 145.

Statements that are open or ambiguous create the potential for misunderstanding, non-compliance with the regulation and could result in regulatory action, aircraft grounding or worse.

The procedures contained in your exposition should describe the detailed processes you follow to comply with the applicable provision in the legislation. They cannot be simple policy statements indicating that you will comply with the relevant elements of the regulation when using a process/procedure.

The exposition must be fully reviewed on a regular basis by your organisation and by us, during our audit cycle.

Your Exposition must be kept up to date considerate of the latest legislation changes and their applicable Acceptable Means of Compliance and associated guidance.

Line Maintenance

Line Maintenance generally refers to minor, unscheduled or scheduled maintenance carried out on aircraft that includes:

  • unscheduled maintenance resulting from unforeseen events such as trouble shooting or defect rectification.
  • scheduled tasks not exceeding the weekly check or equivalent specified in the approved aircraft maintenance program.
  • scheduled checks that contain servicing, inspections or both, that do not require specialised training, equipment or facilities and that have been assessed and accepted for inclusion in the line maintenance scope of work.
  • aeronautical product replacement with use of external test equipment if required. Aeronautical product replacement may include products such as engines and propellers where environmental conditions are suitable.
  • maintenance performed on aircraft after a period of being out of service (such as aircraft in storage) when agreed in advance with us.
  • the need to access a hangar (even if the activity is permitted under a line maintenance scope of approval) considering the type of aircraft, the maintenance event type/complexity, the environmental and weather conditions.

It is not line maintenance when:

  • there are a significant number of different types of tasks to be carried out during a single input, even if when considered singularly they may still fall within the definition of line maintenance but together clearly require the use of base maintenance production planning support and/or base maintenance certificate of release to service process (category C staff supported by B1 andB2 certifying staff) in order to ensure that the maintenance ordered has been properly carried out before release to service.
  • replacement of any major aeronautical products where the related maintenance procedures clearly require the use of a hangar environment requiring special ground support equipment and/or structured production planning and/or complex and lengthy maintenance.
  • any scheduled maintenance task requires extensive disassembly of the aircraft and/or extensive in-depth inspection.
  • the maintenance event involves major repairs and/or major modifications.
  • trouble shooting and/or defect rectification requires special ground support usually relevant to base maintenance (for example, special equipment, structured production planning, complex and lengthy maintenance).
  • a scheduled maintenance event, has already been identified in the planning phase as significant in terms of duration and/or man-hours.
  • a work package requires a complex team composition in terms of numbers and categories (avionic, structure, cabin, NDT, etc.) of staff involved per shift.
  • the maintenance event is managed by B1 and B2 maintenance certification staff and the release by a C certifying staff. (Small aircraft - the release responsibilities can be performed by suitably authorised Category B certifying staff).
Last updated:
24 Dec 2021
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