Manual of Standards Part 171 - Aeronautical Telecommunication and Radio Navigation Services

MOS 171 organises regulatory expectations around a small set of recurring concepts, each defined in the instrument and then applied across technical and organisational requirements.

Aeronautical telecommunication service. Defined to include aeronautical broadcast, fixed, fixed telecommunication network, telecommunication network, aeronautical mobile services supporting ATS, and any system that processes or displays air traffic control data (Section 1.2 definition; Section 2.1.1.1). The MOS lists specific exclusions so operators understand the perimeter of regulatory coverage, for example AWIB stations and certain non-ATS ground stations are excluded (Section 2.1.1.1 notes).

Aeronautical radio navigation service. Defined as a radio navigation service intended for the safe operation of aircraft and including radio determination such as radar surveillance services supporting ATS (Section 1.2 definition; Section 2.2.1.1). The MOS then enumerates the radio-navigation facilities that fall within that concept (Section 2.3.1.1).

Facility. The MOS treats a facility as one or more items of equipment at one or more locations that together provide a telecommunication or radionavigation service (Section 1.2 definition). That definition permits a single “facility” to be geographically distributed or multi-component, which has implications for configuration control, safety cases and site logs (see Sections 7.1.1.1(c), 3.2.1.2 and 8.2.1.1-3).

Safety Management System (SMS) and safety case. SMS is a managerial construct that defines policies, procedures and practices for the safe provision of services and for managing change (Section 1.2 definition). MOS 171 states necessary SMS features (organisational responsibilities, safety objectives, hazard identification and change management processes, internal reporting and review) and requires safety cases to be prepared using recognised methodologies for safety risk assessment where new services or changes deviate from the certificate or the SMS requires prior notification (Sections 3.1.1.1 and 3.2.1.1-4). The MOS also provides that existing services with more than two years demonstrated safe operation need not be covered by a baseline safety case (Section 3.2.1.3).

Support services. MOS 171 captures information-services and carriers that are necessary for the functioning of telecommunication or radionavigation services, defining them as “support services” (Section 1.2 definition). This broad definition brings some digital systems and data carriers within the part’s governance when they are necessary to service delivery.

Document and data control, records and test equipment. The MOS treats documentary control, record keeping and test-equipment calibration as integrated safety and compliance tools: it prescribes what documents must be held, how document currency is controlled, the need for calibrated and traceable test equipment, and explicit record retention periods and site log content (Chapters 6-8).

Service and facility classification. Chapter 2 and Section 2.3 present a taxonomy of services and facilities which drives compliance obligations, from VHF and HF air/ground voice communications and instrument landing systems through to flight data processing, surveillance systems and GNSS augmentation stations. That taxonomy is the practical axis along which competence, test and documentation requirements are applied.

Regulatory primacy and instrument status. Finally, MOS 171 positions itself in the regulatory hierarchy: it is issued under the Act and CASRs (Section 1.1.2.1), is a disallowable legislative instrument (Section 1.1.2.4), and is explicit that CASRs prevail over MOS in case of inconsistency (Section 1.1.2.5), while MOS may differ from ICAO Annexes and will be the operative Australian standard where that occurs (Section 1.1.3.1).

These concepts are operationalised throughout the MOS: safety management and safety cases underpin change control; the facility and service lists set the scope of technical standards; document control, records and calibrated test equipment concretise evidentiary expectations; and technician qualification and authorisation provisions translate standards into workforce competence rules.

The primary regulated parties under MOS 171 are approved aeronautical telecommunication and aeronautical radio navigation service providers, including organisations approved under CASR Part 171 and ATS providers approved under CASR Part 172 where their services and facilities are listed in Chapter 2 and Section 2.3 (Section 2.1.1.1 and Section 2.3.1.1). The MOS requires these service providers to document internal operational rules in Operational Manuals and to implement and maintain the standards set out in the MOS (Section 1.1.2.6). CASA itself is an actor in the regime: it produces the MOS, owns the technical content responsibility within Flight Standards Branch, Standards Division, and may receive suggested changes from service providers and other technical areas (Sections 1.1.5.1-1.1.5.3).

Operational staff and supervisors are directly affected through the MOS’ personnel provisions. Technicians performing operation and maintenance functions must meet minimum academic qualifications (a diploma-level technical qualification in listed disciplines or equivalent) or, for trade-only roles, trade qualifications (Section 5.1.1.1-5.1.1.2). Approved organisations must issue authorising certificates that identify scope and currency of authorisations and ensure competency-based training and assessment by appropriately qualified assessors (Sections 5.2.1.1-5.2.1.2). Organisations also bear the ongoing burden of refresher training and recency checks (Section 5.2.2.1).

Designers and certified/authorised designers have an interaction with providers where landing system suitability must be communicated by the provider to a designer for Special Authorisation Category I approaches (Section 10.1.1.2). The MOS cross-references regulatorily significant CASR provisions (for example the certificate reference in Section 3.2.1.4(a) to regulation 11.060 of CASR), so certificate-holders and applicants are within scope.

Third parties are affected indirectly. Aerodrome operators and support service providers are included in interface and SMS definitions where interface arrangements and responsibilities are required (Section 3.1.1.1(g)). Entities supplying test equipment and calibration services are affected by the calibration traceability requirements (Section 6.1.1.4). Providers of databases and meteorological displays fall within the MOS’ facility list and thus face documentation and data control expectations (Section 2.3.1.1(z) and (aa)).

Who pays and who decides. The MOS allocates the compliance costs to service providers and approved organisations, who must implement SMS, safety cases, qualification regimes, test equipment calibration, recordkeeping and security programs (see Chapters 3, 5, 6, 7, 8 and 9). CASA is the decision-maker on technical content, the issuer of the MOS under the Director of Aviation Safety and the recipient of proposed changes (Sections 1.1.5.2 and 1.1.5.2A), and CASA retains the statutory enforcement and certification functions under the Act and CASRs (Section 1.1.2.2A).

Duties under MOS 171 are organised by function: management systems, technical standards, personnel competence, documentation, records, equipment calibration and security.

Safety Management System duties. Approved service providers must have an SMS that contains specified elements: safety policy and objectives; clearly assigned organisational responsibilities; establishment and monitoring of safety levels; internal safety review processes; internal reporting and management of incidents; hazard identification, assessment and mitigation; interface arrangements with internal and external parties; and change management processes (Section 3.1.1.1(a)-(h)). The MOS requires safety cases to use recognised risk-assessment methodologies and to identify hazards, assess risk, and define mitigation for unacceptable risks (Section 3.2.1.1-2). A safety case must be prepared for a proposed new service or change if it would not be in accordance with the provider’s certificate or the SMS requires prior notification (Section 3.2.1.4(a)-(b)). Existing services with more than two years’ demonstrated safe operation need not be covered by a baseline safety case (Section 3.2.1.3).

Technical and facility duties. Providers must ensure necessary test facilities are available and use documented procedures to control, calibrate and maintain equipment; calibration must be traceable to national measurement standards and calibration records retained (Section 6.1.1.1-6). For landing systems, providers must meet specific equipment classification and operational monitoring requirements for Special Authorisation Category I and II operations (Section 10.1.1.1 and 10.1.2.1). Providers must hold a set of required documents essential to the provision of services, including Annex 10/11, functional and technical specifications, configuration records, interface agreements and safety cases (Section 7.1.1.1(a)-(h)).

Personnel and authorisation duties. Approved organisations must issue authorising certificates that identify technician identity, scope of authority and currency, and must not grant an authorisation unless the technician has undergone competency-based training and been assessed as competent by an appropriately qualified assessor (Sections 5.2.1.1-2). Organisations must also have refresher training and recency-check procedures (Section 5.2.2.1).

Document control and records duties. Organisations must have document and data control processes that ensure documents are authorised by a designated authority, currency can be readily determined, documents are available where needed, only current versions are available, and a master copy is securely held (Section 7.2.1.1-2). Records must provide a traceable history across the lifecycle and include design, procurement, testing, risk assessments, facility performance, failures, defect investigations, and technician competency records (Section 8.1.2.1(a)-(g)). Site logs must be kept for all facilities, record occurrences and actions relating to operations and maintenance, be signed and time-stamped, and retained for at least five years (Section 8.2.1.1-4).

Security and continuity duties. A security program that minimises unauthorised access, entry by animals or malicious damage must be established; it must prevent and detect damage, provide response procedures to threats, and prevent unauthorised access (Section 9.1.1.1 and 9.1.2.1(a)-(c)). Power, HVAC and emergency supplies are included as essential services in facility lists (Section 2.3.1.1(x)).

Rights and limited flexibilities. MOS 171 recognises limited flexibilities: where a facility is not technically complex CASA may agree to accept lesser qualifications for technicians (Section 5.1.1.3). For assessors, the MOS allows assessment to be conducted by a team where one person holds the assessor training unit and others hold the technical unit competencies (Section 5.2.1.2(c)). Existing services with long demonstrated safety history are not required to prepare a baseline safety case (Section 3.2.1.3).

Instrument status and enforcement context. The MOS clarifies that it is a disallowable legislative instrument and not enforceable unless registered on the Federal Register of Legislative Instruments (Section 1.1.2.4). It also states primacy rules: the CASRs prevail over MOS where inconsistent; MOS prevails over ICAO standards where it is different (Sections 1.1.2.5 and 1.1.3.1). In practice that means duties in MOS will be enforced through regulatory oversight and certificate conditions under the CASRs rather than MOS itself being a stand-alone criminal statute.

MOS 171 itself does not set out penalty scales or criminal offences. The MOS is a standards instrument that prescribes the content of what CASA expects providers to institute and document, and it operates within the enforcement architecture of the Civil Aviation Act 1988 and the CASRs. The MOS states that it is a disallowable legislative instrument and that it is not enforceable unless it is registered on the Federal Register of Legislative Instruments (FRLI) and tabled in Parliament (Section 1.1.2.4). Enforcement and any sanctions therefore flow from the CASRs and the Act rather than from the MOS text.

Enforcement mechanisms are implied through certification, monitoring and the CASR cross‑references that appear in the MOS. For example, MOS provisions refer to certificates issued under regulation 11.060 of the CASR when determining whether a safety case is required (Section 3.2.1.4(a)). The CASR framework governs approval, certification and the conditions on which services may operate; the MOS supplies the standards that must be evidenced to maintain compliance with those conditions. CASA, through its Director of Aviation Safety and Flight Standards Branch, is responsible for the MOS technical content and for amendments (Sections 1.1.5.1 and 1.1.5.2). CASA also performs the regulatory oversight that implements enforcement in practice (Section 1.1.2.2A).

Prosecutorial or administrative penalties would therefore derive from breaches of CASR obligations or certificate conditions. The MOS identifies documentary and operational duties that, if not met, are likely to be material to CASA’s certification decisions and oversight actions: absence of an SMS meeting the required elements (Section 3.1.1.1); failure to prepare required safety cases where a new service or change is outside certification parameters (Section 3.2.1.4); technician authorisation without competency evidence (Section 5.2.1.2); failure to calibrate equipment to national standards and retain calibration records (Section 6.1.1.3-6); inadequate records and site logs (Sections 8.1.2 and 8.2.1.1-4); and inadequate security programs (Section 9.1.2.1). In enforcement terms such failures would be actionable under the CASRs’ compliance and certification apparatus.

Operationally, non-compliance will have immediate practical effects: CASA may deny or suspend certificates, require remedial action, or impose conditions; these are tools available in the CASR/Act framework rather than in the MOS text itself. The MOS makes explicit that discrepancies between MOS and CASR are resolved in favour of the CASR (Section 1.1.2.5), which is relevant where a provider seeks to resist enforcement by relying on MOS language.

Finally, the MOS’ disallowable instrument status (Section 1.1.2.4) creates an administrative check on its content. If MOS were not properly registered or tabled the instrument’s enforceability could be challenged, and where MOS provisions conflict with the CASR or Act those higher instruments control.

MOS 171 is expressly situated within a multi-tiered regulatory hierarchy. At the top is the Civil Aviation Act 1988, under which CASA is established and given safety-related functions; the MOS expressly states its issued under the Act and the relevant CASR provisions (Section 1.1.2.1). The CASRs themselves provide the regulatory framework within which MOS operates; the MOS is intended to be read as CASA’s uniform standards that give effect to CASR obligations (Section 1.1.2.2-1.1.2.3). MOS also identifies particular CASR cross-references for specific requirements: technician qualifications (CASR Part 171.050), SMS (CASR Part 171.086) and the list of services (CASR Part 171.020) , these CASR pointers appear in the MOS headings.

On international obligations, MOS 171 links to ICAO Standards and Recommended Practices. It states its basis in ICAO Annex 10 and that the MOS should be read in conjunction with ICAO Annex 10 Volumes I to V and Annex 11 and ICAO Doc 8071 (Section 1.1.1.1 and Section 1.1.6.1). However, the MOS is explicit that where there is a difference between an ICAO Annex standard and the MOS, the MOS standard shall prevail for Australian application (Section 1.1.3.1). Differences with ICAO that are declared by Australia are published in the Aeronautical Information Publication GEN 1.7 (Section 1.1.4.1). That means Australian domestic standards as set out in MOS 171 are the operative rule for providers, even where they depart from ICAO recommendations.

Administrative law interfaces are also explicit. The MOS is a disallowable legislative instrument and must be registered on the FRLI and tabled in Parliament within specified parliamentary sitting days (Section 1.1.2.4). That status subjects the MOS to parliamentary scrutiny and potential disallowance procedures that exist for disallowable instruments. CASA’s internal procedures for proposing MOS amendments allow suggestions from CASA technical areas, service providers and ATS providers (Section 1.1.5.3), and CASA’s Director of Aviation Safety issues and amends the MOS under delegated authority (Section 1.1.5.2).

Inconsistency rules. The MOS stipulates that where CASR and MOS conflict the CASR prevails (Section 1.1.2.5). That is the conventional legal hierarchy: CASR obligations and penalties govern enforcement, while MOS supplies the detailed standards and acceptable means. Practical consequences follow: affected parties must read MOS requirements in light of CASR obligations, and if a provider believes a MOS requirement is inconsistent with the CASR the CASR will control.

Finally, the MOS interfaces with certificate regimes and application processes under CASR , for instance, certification references in Section 3.2.1.4 tie safety case obligations to CASR-issued certificates. The MOS therefore operates as the technical, documentary and operational standard set that implements obligations created and enforced under the Civil Aviation Act and the CASRs.

The MOS compilation supplied includes amendment history and a table of instruments that have altered MOS 171 since its initial commencement. The original MOS 171 commenced on 1 May 2003 (Table of Orders). A subsequent amendment instrument, MOS 171 2006 No. 1, is recorded with FRLI notification dated 15 August 2006 and commencement 16 August 2006 (Table of Orders). A later consolidated amendment, titled Manual of Standards Parts 139, 171, 172 and 173 Amendment Instrument 2016 (No. 1), was registered on FRLI on 13 January 2016 and commenced on 3 March 2016 (Table of Orders).

The MOS compilation contains a Table of Amendments that identifies specific provisions affected by the 2016 amendment (F2016L00042). The table shows that paragraph 1.1.2.1 was repealed and substituted (rs.), paragraph 1.1.2.2A was added (ad.), paragraph 1.1.2.4 was repealed and substituted (rs.), paragraph 1.1.5.1 was repealed and substituted (rs.), paragraph 1.1.5.2 was repealed and substituted (rs.), and paragraph 1.1.5.2A was added (ad.). In Chapter 3, an insertion was made after the chapter heading (ad.) by the 2006 instrument, and Section 3.1 and 3.2 were amended in the 2006 instrument. Paragraph 3.2.1.4(a) was amended by the 2016 instrument. Chapter 10 was added by the 2016 instrument (ad.). Section 1.2 was amended earlier in MOS 171 2006 No. 1.

The notes at the end of the MOS provide consolidated tracking showing which paragraphs were added, repealed, substituted or amended and by which instrument reference. That tracking is important for users because the MOS is a disallowable instrument and updates can change technical or procedural obligations for service providers. The compilation itself notes it was prepared on 3 March 2016 taking into account amendments up to the 2016 Amendment Instrument (as stated on the cover and in the Table of Orders).

Operationally, the MOS also prescribes the internal CASA governance for handling changes: the technical content responsibility lies with relevant technical areas within Flight Standards Branch, Standards Division (Section 1.1.5.1), the document is issued and amended under authority of the Director of Aviation Safety (Section 1.1.5.2), and suggestions for change should be directed to the Manager, Air Traffic Management Systems Standards Section (Section 1.1.5.2A). Requests for changes may be initiated by CASA technical specialists, aeronautical telecommunication and radio navigation service providers, and ATS service providers (Section 1.1.5.3). This governance structure explains how amendments are generated and processed prior to instrument amendment and FRLI registration.

The MOS text supplied does not cite or summarise any litigation, nor does it reference decisions of courts or tribunals. There are no case names or judicial authorities included in the document. MOS 171 is primarily an administrative standards instrument that sets technical and procedural requirements; as such it does not itself report adjudications or litigation outcomes.

Legal challenges that would engage MOS 171 are likely to occur in the broader context of CASR enforcement or administrative law review of CASA decisions. The MOS includes procedural features relevant to such challenges: its status as a disallowable legislative instrument means that procedural irregularities in registration or tabling could be an administrative argument (Section 1.1.2.4). Its statement that CASR prevails in the event of inconsistency (Section 1.1.2.5) identifies a clear statutory hierarchy which a court or tribunal would apply in any dispute about whether MOS provisions create enforceable obligations beyond what the CASR authorises.

Other potential litigation-focused points arise from the MOS’ interaction with certification and safety-case obligations. For example, the MOS ties safety-case obligations to certificate terms and CASR regulation 11.060 (Section 3.2.1.4(a)); disputes about whether a change requires a safety case or the sufficiency of a safety case could therefore produce administrative review proceedings concerning CASA’s decisions on certification compliance. Similarly, failure to meet MOS standards for technician authorisations, calibration traceability or recordkeeping could underpin CASA enforcement action which might be litigated or administratively reviewed under the Act/CASR enforcement regime.

Because the MOS itself does not include penalty provisions or case law citations, any litigation history will be recorded in CASA enforcement files, tribunal or court decisions interpreting CASR obligations, or judicial review proceedings that reference MOS as part of CASA’s regulatory practice. Those materials are not included in the MOS document supplied.

Several practical traps and points of friction emerge from close reading of MOS 171. Below are concrete items that organisations should not overlook.

Instrument status and enforceability. The MOS is a disallowable legislative instrument and is not enforceable unless registered on the FRLI and tabled in Parliament (Section 1.1.2.4). Organisations should therefore ensure they are working off the current, registered MOS on FRLI rather than an outdated local copy. The MOS also states that where there is disparity between MOS and the CASR, the CASR prevails (Section 1.1.2.5). It also states that where MOS differs from ICAO Annexes the MOS standard shall prevail in Australia (Section 1.1.3.1). These two primacy rules can interact: a provider cannot rely on ICAO norms against CASR or MOS if an inconsistency exists.

Scope exclusions and inclusions. Some services and ground stations are explicitly excluded from Part 171 coverage (for example AWIB, UNICOM, CAGRS, PAL and AFRU are not included , Section 2.1.1.1 notes). Conversely, the MOS explicitly includes systems that process or display air traffic control data and certain electronic briefing and flight-plan lodgement services (Section 2.1.1.1(f)-(g)). Misclassification of a service as out of scope can lead to under‑compliance risk.

Safety-case baseline exemptions. Existing ATEL/ANAV services with more than two years’ demonstrated safe operation at initial certification do not need a baseline safety case (Section 3.2.1.3). That is a time-based exemption; organisations that believe they qualify should document the evidence of operation history, because subsequent changes may trigger safety-case requirements (Section 3.2.1.4).

Technician qualification flexibility and risk. The MOS allows CASA to agree to lesser qualifications where the facility is not technically complex (Section 5.1.1.3). Relying on this flexibility requires CASA agreement; operating without it risks non-compliance with the minimum qualifications listed (Section 5.1.1.1-2).

Assessment arrangements. The MOS requires assessors to have both assessor training and formal technical competency, but allows assessment teams where no single assessor holds all competencies (Section 5.2.1.2(c)). Organisations using a team approach must ensure record evidence of assessor competencies and the joint assessment process to withstand regulatory scrutiny.

Traceability of calibration. Calibration intervals and traceability to national measurement standards are mandatory (Section 6.1.1.4). Non-traceable calibration or inadequate calibration records are explicit failures in the MOS (Sections 6.1.1.4-6). When test equipment is discovered out of calibration, organisations must assess the validity of previous test results (Section 6.1.1.7). That can generate retroactive remediation cost and operational risk.

Document control centralisation. The MOS requires a securely held master copy and indexation of documents referenced in the Operations Manual (Sections 7.2.1.2(e) and 7.2.1.3). Failure to centralise control can lead to inconsistent versions in the field and regulatory non-compliance.

Site log retention and evidentiary detail. Site logs must record occurrences and actions, include date/time and signature, and be retained for at least five years (Sections 8.2.1.2-4). Electronic logging systems must meet the same criteria and ensure legibility and permanence (Section 8.1.2.1). Inadequate logging can impede incident investigation and regulatory responses.

Security program scope. The MOS requires security measures to prevent unauthorised access, malicious damage and entry by animals (Section 9.1.1.1 and 9.1.2.1). The inclusion of animals is a specific and perhaps overlooked commodity risk for remote installations, requiring fencing or other measures.

Landing system classification detail. For Special Authorisation Category I and II operations, precise transmitter classifications and system configurations are required (Section 10.1.1.1(a) and 10.1.2.1(a); also frequency‑paired DME requirement in 10.1.2.1(c)). The MOS also requires system-level controls to prevent opposite-end localiser radiation when two ILS serve opposite runway ends (Section 10.1.1.1(b) and 10.1.2.1(b)). These are technical constraints that can require capital investment or operational changes.

Who pays, who decides, and behavioural effects. Service providers pay for the costs of SMS implementation, safety-case preparation, technician training and certification, equipment calibration and records management. CASA decides on MOS content, certification and whether to accept lesser qualifications or waive baseline safety cases where permitted (Sections 1.1.5.2A and 5.1.1.3). Behavioural effects include more formalised change-control, centralised document control, structured competence assessment, and tighter calibration and record-keeping practices.

Each of these “gotchas” is grounded in a specific MOS provision. Organisations should map the MOS text to their operations, document where discretion from CASA is required, and avoid assuming informal practice will be sufficient evidence for compliance.

Compliance with MOS 171 is operational and documentary. Below is a practical, stepwise blueprint grounded in the MOS provisions.

1. Confirm instrument currency and scope. Obtain the registered MOS 171 from the FRLI and confirm the current consolidated text and amendment history (Section 1.1.2.4 and the compilation’s Table of Orders). Map your services and facilities against Section 2.1 and Section 2.3 lists to establish which MOS requirements apply.

2. Embed MOS obligations into the Operations Manual. The MOS expects service providers to document internal actions (Rules) in their Operational Manuals to ensure compliance with MOS standards (Section 1.1.2.6). Index and reference all documents required by MOS in the Operations Manual (Section 7.2.1.3).

3. Establish and document an SMS. Implement an SMS that contains the necessary features listed in Section 3.1.1.1 (policy, responsibilities, safety levels, internal reviews, reporting, hazard assessment, interfaces and change management). Ensure change management processes trigger safety-case preparation where required (Section 3.2.1.4). Use CASA’s Advisory Circular AC 171-02 guidelines for safety-case preparation as noted (Section 3.2.1.2 Note).

4. Prepare safety cases where required. For any new service or change that deviates from certificate conditions or where the SMS requires prior notification, prepare a safety case that uses a recognised safety risk methodology, identifies hazards, assesses risk and specifies mitigations (Section 3.2.1.1-2, 3.2.1.4). Document the rationale for any position that an existing service does not need a baseline safety case under the two-year rule (Section 3.2.1.3).

5. Implement competency regimes and authorisations. Define the minimum qualifications in job descriptions consistent with Section 5.1.1.1-2 and obtain CASA agreement if you propose lesser qualifications for non-complex facilities (Section 5.1.1.3). Issue authorising certificates that identify scope and currency (Section 5.2.1.1). Ensure assessors have the assessor training and technical competencies or arrange joint assessments and record assessor competencies (Section 5.2.1.2(c)). Put refresher training and recency checks in place (Section 5.2.2.1).

6. Control test equipment and calibration. Maintain the necessary test facilities and documented procedures for calibration and maintenance (Section 6.1.1.1-2). Ensure calibration is traceable to national measurement standards, mark calibration status visibly and retain calibration records (Section 6.1.1.4-6). If equipment is found out of calibration, assess validity of prior tests and document corrective action (Section 6.1.1.7).

7. Put document and data control procedures in place. Authorise documents by designated authority, make currency readily determinable, ensure availability of current versions at points of use, and keep a secure master copy (Section 7.2.1.2(a)-(e)). Ensure essential documentation listed in Section 7.1.1.1 is held and indexed.

8. Set up records and site logs. Implement a records system that captures lifecycle records for design, procurement, installation, testing, commissioning, modification and decommissioning; hazard analysis and risk assessment; facility performance and failures; defect investigations; and technician competency records (Section 8.1.2.1(a)-(g)). Maintain site logs for each facility recording date/time, occurrences and actions, signed by the technician, and retain them for at least five years (Section 8.2.1.1-4).

9. Prepare a security program. Document and implement physical security measures and procedures to minimise unauthorised access, animal entry and malicious damage, and prepare response procedures to threats and incidents (Section 9.1.1.1 and 9.1.2.1(a)-(c)).

10. Meet facility-specific technical standards. For landing systems that will support Special Authorisation Category I or II operations, verify that equipment meets classification and monitoring requirements and that systems prevent opposite-end localiser radiation where two ILS share a runway (Section 10.1.1.1 and 10.1.2.1). Communicate suitability and limitations to designers as required (Section 10.1.1.2).

11. Manage interfaces with external stakeholders. Document interface agreements with ATS providers, aerodrome operators and support service providers as required by SMS interface arrangements and the documents-to-be-held list (Sections 3.1.1.1(g) and 7.1.1.1(e)).

12. Maintain audit trails and evidence. Keep indexed master copies of all documents and records, and ensure all compliance evidence is retrievable for audit or CASA inspection. Where MOS allows flexibility (for example, lesser technician qualifications), secure written CASA agreement and retain that authority documentation (Section 5.1.1.3).

13. Use CASA channels for change and clarification. Direct suggested changes or technical queries to the Manager, Air Traffic Management Systems Standards Section (Section 1.1.5.2A) and be aware CASA may issue amendments under the Director of Aviation Safety (Section 1.1.5.2). Monitor FRLI for instrument updates.

Following these steps aligns operations with the MOS text. Key implementation risks are documentary gaps, inadequate assessor evidence, non-traceable calibration, incomplete safety cases for qualifying changes, and inadequate site logging and security measures. Each of these risks is directly identified by MOS provisions and should be managed as part of the provider’s SMS and operational quality system.