Civil Aviation Order 100.7 Instrument 2015

CAO 100.7 establishes a set of technical concepts used throughout the instrument. The definitions in section 2 are the primary source for these concepts and should be read closely when applying the CAO.

• Empty weight and empty weight CG. The instrument defines "empty weight" to include fixed equipment mandatory for all operations, fixed ballast, unusable fuel and total quantities of oil, engine coolant and hydraulic fluid but to exclude "all other items of disposable load" (s 2). "Empty weight CG" is the aircraft’s centre of gravity position corresponding to that empty weight; the CAO repeatedly uses the phrase "empty weight and empty weight CG" as the baseline for load data and regulatory compliance (paras 3.5, 5.2(1), 6.1 and 7.1).

• Operating weight and operating weight CG. "Operating weight" is defined as empty weight plus those items of removable equipment and disposable load which remain constant for the particular type of operation being conducted (s 2). Where an operator uses operating weights the load data sheet must record operating weight and operating weight CG and list removable equipment and disposable load included in that operating weight (para 5.2(1)).

• Fleet and fleet (weight and CG) values. A "fleet" is defined as two or more aeroplanes of the same model and configuration operated by the same operator (s 2). "Fleet (weight and CG) values" are the average operating weight and average CG established for aircraft in a fleet. The CAO provides a regime allowing certain aeroplanes to be operated on averaged fleet values, subject to detailed inclusion, variation and sampling rules in subsections 3A and 3B. Important constraints include that an aeroplane cannot be included unless it has been weighed within the previous four years (para 3A.3), limits on individual aircraft deviations from fleet averages (para 3A.5), and sample sizes and re‑establishment intervals for fleet values (paras 3B.1-3B.5).

• Validation. "Validation" of an aircraft’s weight means determining the aircraft’s weight in accordance with para 3.5. For aircraft types in items 3 and 4 of the reweigh table, a weight control officer may validate the weight by examining records and the previous weighing summary and, if satisfied that records are accurate and complete, declaring in writing that the record shows the current empty weight and empty weight CG and issuing a new load data sheet without weighing (para 3.5).

• Weight control and weight control officer. "Weight control" is defined as the determination of empty weight and empty weight CG, development and approval of loading data, maintenance of a record of weight alterations and overall supervision of these activities, including oversight of control, maintenance and operation of the aircraft to ensure compliance with CAR provisions on loading, weight and CG (s 2). A "weight control officer" is a person holding an airworthiness authority under paragraph 33B(1)(e) of CAR (s 2). The CAO requires weighings be carried out under the control of a weight control officer whose appointment covers the activity or by a person meeting specific training and practical experience criteria set out in para 4.1A.

• Loading system and load data sheet. A "loading system" is a system to ensure an aircraft is loaded within approved weight and CG limits at all times during flight (s 2). A "load data sheet" is the document prepared for an individual aircraft providing weight and CG information for use in the loading system (s 2). The CAO prescribes what must appear on the load data sheet, when it must be renewed, who may approve loading data (para 5.2(3)) and retention of duplicate copies on the ground (para 5.2(5)).

• Technical measurement concepts. The CAO sets measurement tolerances for scales (para 4.2), calibration requirements and acceptable calibrators (para 4.3 and 4.3A), the requirement for two independent consecutive weighings and acceptable agreement tolerances (paras 4.5-4.6) and the obligation to record weighing details in an aircraft weighing summary approved by CASA (para 4.7).

These concepts form a network of duties and technical specifications. The CAO links the operational concepts of "empty weight", "operating weight", "fleet values" and "load data" to concrete measurement, sampling and documentation rules, creating a compliance ecosystem that ties daily loading decisions to periodic technical events such as weighings, validations and re‑establishment of fleet averages.

CAO 100.7 allocates duties and constraints across a set of clearly identifiable actors. The instrument’s operation principally affects the following groups, with the obligations and decision rights specified in particular provisions:

• Registered operators and owners. Registered operators are repeatedly given active obligations: to ensure an aircraft is weighed before an initial certificate of airworthiness unless alternate methods are accepted (para 3.1(1)-(2)); to reweigh or validate at prescribed intervals for commercial operations (para 3.2); to keep load data sheets and aircraft logbooks current and, where private aircraft are not reweighed, to endorse logbooks and load data sheets restricting commercial use (paras 3.3-3.4); to maintain continuous records of weight alterations and amend equipment lists when equipment changes occur (paras 6.1, 6.1A); and for operators using fleet values to prepare and maintain documented fleet procedures, select sampling aircraft for re‑establishment and ensure each aeroplane is weighed at least once every 9 years (subsections 3A and 3B).

• Pilots in command. The instrument creates a direct operational prohibition on pilots in relation to loading data approved under this CAO: "the pilot in command of the aircraft must not commence a flight if the pilot has not received evidence, and taken such action as is necessary to ensure, that the data have been complied with" where CASA has approved the loading data (para 5.1). This imposes an affirmative verification duty before flight where CAO loading data applies.

• Weight control officers and persons performing weighings. Weighings must be carried out under the control of a weight control officer whose appointment covers the activity, or by a person meeting the para 4.1A conditions (para 4.1 and 4.1A). Weight control officers are expressly authorised to validate weights under para 3.5 and to certify empty weight and empty weight CG after weighings (para 4.7). The CAO ties technical responsibilities and signature authorities to weight control officers.

• CASA and other regulators. CASA is directly referenced with multiple powers: to require an aircraft to be weighed or reweighed where "reasonable doubt" exists as to submitted data (para 3.1(3)); to approve persons, scales or organisations for calibration, to approve aircraft weighing summary forms, to approve loading data (para 5.2(3)), and to require new weighings where inadequate weight control is found (para 6.5). The CAO also ties calibration acceptance to the National Measurement Institute’s approvals and to accreditation bodies such as NATA or ILAC member conformity (para 4.3 and 4.3A).

• Maintenance organisations and scale service providers. The CAO sets technical calibration and accuracy standards for scales and requires calibrations within 12 months by specified entities (para 4.3). This brings scale manufacturers, approved calibration organisations, and service providers into the compliance chain. Operators must ensure scales used meet the accuracy tolerance set out in para 4.2.

• Sport aviation bodies and ASAOs. The instrument explicitly excludes certain aircraft administered or weighed under sport aviation bodies other than an approved self‑administering aviation organisation (ASAO) or those administered by an ASAO that has an approved function for approving weight control procedures (see Application paras (c)-(e)). Those exclusions mean some sport‑administered aircraft follow different weight control procedures where CASA has accepted or approved those bodies’ procedures.

• Aircraft types differentiated by MTOW and configuration. The CAO differentiates obligations by aircraft type and MTOW: multi‑engine aeroplanes and rotorcraft above specified MTOW thresholds have specific reweigh intervals (para 3.2 table). The ability to use placards for loading systems is available for aircraft with MTOW 5 700 kg or less (para 5.2(2A)).

Overall, operators and owners carry the ongoing compliance burden for weighings, records, fleet sampling and load data. Pilots have the immediate in‑flight compliance duty when CAO‑approved loading data applies. CASA and accredited calibration bodies have oversight and technical approval roles. Sport aviation organisations and ASAOs may be outside the CAO’s scope where CASA has approved their own procedures, according to the application section.

CAO 100.7 imposes specific duties on operators, pilots, weight control officers and others, and confers certain procedural rights and discretions. Below I list the principal duties and the corresponding decision rights or discretions provided in the instrument, with direct references to the governing paragraphs.

Duties on operators and owners

• Initial weighing: Except as allowed under para 3.1(2), every aircraft must be weighed before the initial issuance of a certificate of airworthiness (para 3.1(1)). CASA may waive this requirement where a weight control officer or other specified person is satisfied that empty weight and CG have been established by other means (para 3.1(2)).
• Periodic reweighing or validation: Operators of aircraft used in commercial operations must reweigh or validate at the intervals set out in the para 3.2 table according to aircraft type and MTOW (para 3.2 and table).
• Private to commercial restriction: If an aircraft used in private operations has not been reweighed or validated to the relevant interval, it must not be used in commercial operations until the reweigh/validation is done (para 3.3).
• Endorsements: Registered operators must ensure the aircraft’s logbook or alternative document and the load data sheet are endorsed with the restriction in para 3.4 when the aircraft is restricted to private operations pending weighing.
• Record keeping: A complete and continuous record of changes in empty weight and empty weight CG must be maintained for each aircraft, including all alterations affecting weight and balance (para 6.1). Equipment lists must be amended when equipment changes affect empty or operating weight (para 6.1A).
• Load data custody: The owner or operator must keep duplicate copies of all current approved loading data in a safe place on the ground (para 5.2(5)).
• Fleet procedures: Operators using fleet values must document procedures for establishment, review and use of those values and comply with the inclusion and sample rules in subsections 3A and 3B (paras 3A.4, 3B.1-3B.5).

Duties on pilots and flight crew

• Pre‑flight compliance evidence: Where loading data prepared in accordance with this subsection is approved by CASA, the pilot in command must not commence a flight unless they have received evidence and taken necessary action to ensure the data have been complied with (para 5.1).

Duties on weight control officers and persons who weigh aircraft

• Supervision and certification: Aircraft weighings must be carried out under the control of a weight control officer whose appointment covers the activity, or by a person meeting the para 4.1A requirements (para 4.1 and 4.1A). The empty weight and empty weight CG must be certified as correct by the weight control officer or a para 4.1A person (para 4.7).
• Validation authority: For some aircraft types (items 3 and 4 in the reweigh table), a weight control officer may validate an aircraft’s weight using cumulative records and issue a new load data sheet without physically reweighing, subject to specified examinations and declarations (para 3.5).

Discretions and CASA powers

• CASA may require weighings: CASA has discretion to require an aircraft to be weighed or reweighed where reasonable doubt exists as to the accuracy of submitted weight and balance data (para 3.1(3)), and may require reweighing where it considers that adequate weight control has not been exercised (para 6.5).
• Approval roles: CASA may approve loading data prepared under the CAO, approve persons to conduct weighings (via para 4.1A training approvals), approve weighing summary forms, and accept calibration organisations for scales (paras 4.1A, 4.3, 4.7, 5.2(3)).

Measurement and documentation obligations

• Scales and calibration: Scales must meet an accuracy tolerance of ±0.2% of applied load or ±2 kg, whichever is greater (para 4.2). Scales used must have been calibrated within the preceding 12 months by the manufacturer, an organisation approved by the National Measurement Institute, or an organisation using a reference standard with a valid calibration or verification certificate (para 4.3). Para 4.3A specifies what makes a certificate valid and which accreditations qualify.
• Weighing methodology: Empty weight and empty weight CG must be determined from two consecutive independent weighings with the load removed between weighings (para 4.5). If the first two weighings differ by more than 0.2% of mean weight or 10 kg, further weighings must be undertaken until two consecutive weighings agree within that tolerance (para 4.6). Weighing details and determinations must be entered in an aircraft weighing summary approved by CASA (para 4.7).
• Trigger thresholds for load data renewal: Load data must be renewed where modifications or recorded weight changes exceed specified thresholds for aeroplanes and rotorcraft (para 6.3). For example, an aeroplane’s empty weight change greater than 0.5% of MTOW or 10 kg (whichever is greater) or empty weight CG change greater than 2% of the maximum permissible CG range or 5 mm triggers renewal (para 6.3(a)).

Rights and conditional flexibilities

• Fleet averaging: Operators may choose to include eligible aeroplanes in a fleet and operate using fleet average weight and CG values rather than individual values, subject to the inclusion rules and sampling obligations (subsections 3A and 3B). This is a conditional procedural right that changes how compliance is demonstrated.
• Placards for small aircraft: For aircraft with MTOW 5 700 kg or less the loading system may be set out on placards if the necessary information can be readily expressed in that format (para 5.2(2A)).
• Validation instead of reweighing: For certain aircraft, a weight control officer has a statutory right to validate cumulative records and issue new load data sheets without reweighing, where the officer is satisfied the records are accurate and complete (para 3.5).

In short, CAO 100.7 combines prescriptive measurement standards with procedural duties, constrained discretions for operators and weight control officers, and supervisory powers for CASA. The duties are technical and documentation heavy, while the rights largely consist of permitted alternatives such as fleet averaging, validation and placard載d loading systems under defined conditions.

CAO 100.7 itself is a Civil Aviation Order rather than primary legislation. The instrument sets mandatory procedural requirements and operational prohibitions, and it interfaces with enforcement and penalty regimes in the Civil Aviation Act 1988 and associated regulations. CAO 100.7 contains provisions that give CASA the ability to require compliance measures and creates direct operational prohibitions that would be enforced under the broader statutory framework.

Direct compliance obligations and immediate operational prohibitions

• Pilot prohibition under approved loading data: Para 5.1 states that when loading data prepared in accordance with the CAO and approved by CASA applies, "the pilot in command of the aircraft must not commence a flight if the pilot has not received evidence, and taken such action as is necessary to ensure, that the data have been complied with." This is a direct duty on the pilot and noncompliance could be enforced under the Civil Aviation Act and Civil Aviation Safety Regulations that give CASA powers to act against unsafe operations.
• Private aircraft restricted from commercial use until weighed: Para 3.3 prohibits use of certain private aircraft in commercial operations unless reweighed or validated. Para 3.4 requires a logbook endorsement restricting the aircraft to private operations until weighed. These create enforceable operational constraints.

CASA insistence and reweighing powers

• CASA may require weighing or reweighing: Para 3.1(3) expressly empowers CASA to require an aircraft to be weighed or reweighed if reasonable doubt exists as to the accuracy of submitted weight and balance data. Para 6.5 similarly empowers CASA to require a new weighing if it considers that adequate weight control has not been exercised over an aircraft. These are enforcement mechanisms that allow CASA to impose corrective technical work and documentation.

Technical certification and approval enforcement

• Certification by weight control officer or approved person: The CAO requires weighings to be certified by a weight control officer or a person who meets 4.1A conditions (para 4.7). Certification functions as evidence for compliance and improper or falsified certification would be actionable under the broader regulatory offences and administrative powers available to CASA.

What the instrument does not specify

• No explicit monetary fines, demerit points, or criminal penalties are set out in CAO 100.7 itself. The instrument does not enumerate specific sanctions for noncompliance. Instead, enforcement and penalties for breaches of the duties in CAO 100.7 would arise via the parent statutory framework: the Civil Aviation Act 1988, the Civil Aviation Regulations and Civil Aviation Safety Regulations which provide the offence and penalty architecture and CASA’s administrative enforcement powers. The CAO is made under statutory authority, and noncompliance with a CAO can feed into regulatory enforcement actions under the Act and regulations referenced in the instrument’s preamble.

Practical enforcement pathways

• Administrative actions by CASA: Given CASA’s powers to require weighing, to refuse approval of loading data, to withdraw or suspend approvals, or to direct grounding pending compliance, the practical enforcement tools are likely to be orders and administrative restrictions. The CAO supplies the technical basis that CASA can use to justify such administrative interventions (see paras 3.1(3) and 6.5).
• Operational grounding and commercial restrictions: Because CAO 100.7 directly conditions commercial use on up‑to‑date weighing and valid load data (paras 3.2-3.4), failure to comply can be enforced in practice by restrictions on operations, including refusal or suspension of commercial operation rights until compliance is shown.
• Evidentiary role of certificates and load data: Signed weighing summaries and approved load data sheets form documentary evidence that CASA and enforcement agencies will rely on. Improper entries, missing duplicate copies (para 5.2(5)) or incorrect load data renewals (para 6.3) create clear compliance deficits that CASA can act upon administratively.

In sum, CAO 100.7 embeds detailed technical and documentary obligations without specifying statutory penalties inside the instrument itself. Enforcement is achieved by operational prohibitions within the CAO, CASA’s powers to require corrective action, and the broader penalty and enforcement regime of the Civil Aviation Act and applicable regulations referenced in the instrument’s enacting provision.

CAO 100.7 is an instrument made under the Civil Aviation Act 1988 and under specific regulatory provisions in the Civil Aviation Safety Regulations 1998 and the Civil Aviation Regulations 1988. The CAO therefore operates as a subordinate instrument that translates statutory and regulatory obligations on weight, loading and centre of gravity into technical, procedural and documentary requirements. The instrument explicitly cross‑references and interacts with other regulatory texts in multiple ways.

Parent statutory and regulatory authority

• Enactment and scope. The instrument is explicitly made under subsection 98(4A) of the Civil Aviation Act 1988 and under regulation 11.245 of CASR 1998 and specific parts of the CAR 1988 (preamble). That places CAO 100.7 within the statutory/regulatory hierarchy and binds it to the powers and limits established under the Act and regulations. For example, para 7.1 states that for purposes of a direction under regulation 235 of CAR setting out the method of estimating weight and CG, the applicable empty weight and empty weight CG must be the most recently determined values specified in a load data sheet issued in accordance with this or previous issues of this section.

• Regulation linkage. The instrument directs users to regulatory provisions. Para 5.1 ties loading data prepared under the CAO to regulation 11.245 of CASR. Para 7.1 ties the "current empty weight" concept to regulation 235 of CAR. These references mean compliance with CAO 100.7 is necessary to meet some regulatory obligations and to provide the evidential basis for directions under those regulations.

Calibration, measurement and accreditation law

• National Measurement Institute, NATA and ILAC. Para 4.3 and 4.3A set out who may calibrate scales and what constitutes a valid certificate for a reference standard. CAO 100.7 therefore imports the National Measurement Institute’s approval framework and recognizes accreditation issued by the National Association of Testing Authorities Australia or entities that are full members of the International Laboratory Accreditation Cooperation. This creates an intersection between aviation safety rules and broader measurement and accreditation law and practice.

Weight control officer authority and CAR. The definition of weight control officer in s 2 links to paragraph 33B(1)(e) of the CAR. That cross‑reference makes the appointment and authority of weight control officers part of the CAR framework. It also means the CAO’s delegation of certain certification and validation powers to weight control officers is coordinated with CAR’s airworthiness authority provisions.

CASA approvals and delegated powers

• CASA’s approval and oversight functions appear repeatedly. Paragraphs 3.1(2), 3.1(3), 4.1A, 4.3, 4.7 and 5.2(3) expressly involve CASA approval or acceptance. For example, para 4.1A permits non‑weight control officer persons to conduct weighings if they have completed a CASA‑approved aircraft weighing procedures course within the last two years and satisfy additional practical experience and equipment conditions. That places CASA as the central approver for exceptions and qualifications under the CAO.

Interaction with sport aviation governance and ASAO arrangements

• Exclusions for sport aviation. The Application section excludes certain balloons, airships and aircraft administered by sport aviation bodies other than ASAOs where the sport body’s weighing procedures have been accepted or approved by CASA (Application paras (a)-(e)). It also excludes sailplanes administered by other sport bodies where weighed in accordance with accepted procedures and operated under specific CAOs (95.4 or 95.4.1). This creates an interface with the Part 149 governance model and ASAO approval pathways.

Operational consistency with flight manuals and placarding

• Unit of measure and flight manual. Para 5.2(4) prescribes metric units for loading data but allows loading data to be stated in pounds where the aircraft’s flight manual uses pounds. This creates an interaction between the CAO and the aircraft flight manual content, and by extension with whatever approvals govern flight manuals.

Regulatory consequences and enforcement

• Directions and regulatory enforcement. The CAO serves as the technical rubric that gives effect to directions under the CAR or CASR. For example, para 7.1 instructs that the empty weight and empty weight CG most recently specified in a load data sheet prepared under this CAO are the applicable values for directions under regulation 235 of CAR. Enforcement actions for noncompliance would therefore flow from the parent Act and regulations but use CAO 100.7 as the technical standard.

In summary, CAO 100.7 is tightly integrated with the Civil Aviation Act, CAR, CASR, CASA administrative approval processes, national measurement and accreditation regimes, and the ASAO/Part 149 governance model. It is a technical instrument that operationalises and provides the evidential basis for compliance with statutory and regulatory obligations on weight, loading and centre of gravity.

CAO 100.7 has been amended multiple times since the original 2015 instrument, and the compilation provided identifies the principal instruments and dates of amendment. The instrument’s own "Table of Orders" and "Table of Amendments" set out the timeline and the specific provisions that were amended, substituted or added.

Chronology and instrument references

• Original instrument. CAO 100.7 Instrument 2015 was registered on 9 July 2015 and commenced on 9 July 2015 (see Table of Orders).
• CAO 100.7 Amendment Instrument 2018 (No. 1). An amendment instrument dated 29 June 2018 (F2018L00961) commenced on 1 July 2018. The Table of Amendments records extensive substitutions and amendments effected by the 2018 instrument. Several paragraphs and subparagraphs were "rs" which indicates repealed and substituted (for example, subsection 1 was substituted by F2018L00961; see Table of Amendments).
• Civil Aviation Order (Flight Operations) Repeal and Amendment Instrument 2021 (No. 1). This instrument was registered on 1 December 2021 and commenced on 2 December 2021. The Table of Orders records an amendment to CAO 100.7 by that instrument (F2021L01680), and the Table of Amendments records specific changes such as amendments to the enacting words and to para 4.1A(d).
• Civil Aviation Order 100.7 Amendment Instrument 2023. That amendment instrument was registered on 11 May 2023 and commenced on 12 May 2023 (F2023L00532). The compilation notes that subparagraph 1(c) was repealed by F2023L00532 and that para 6.6 was repealed by F2023L00532.

How the Table of Amendments records changes

• The instrument includes a Table of Amendments that uses abbreviations: "ad." means added or inserted, "am." means amended, "rep." means repealed, and "rs." means repealed and substituted. The table identifies which provisions were altered and by which amending instrument, for example:
  • The enacting words and subsection references in the early part of the instrument were amended by F2021L01680.
  • Subparagraph 4.1A(d) was amended by F2021L01680.
  • Para 4.3 was repealed and substituted by F2018L00961.
  • Para 4.3A was added by F2018L00961.
  • Paragraph 5.1 was amended by F2018L00961 and F2021L01680.
  • Para 5.2(3) was repealed by F2018L00961.
  • Various changes to para 6.x and para 7.1 are recorded as amended by the 2018 and 2021 instruments, and para 6.6 was repealed by the 2023 instrument.

Substantive content changes visible in the compilation

• Addition of validation pathway and fleet rules. The compilation contains fleet averaging provisions (subsections 3A and 3B) and a validation process for certain types in para 3.5. The Table of Amendments records that many of these changes were introduced or modified across the 2018 and later amendments. The presence of a para 5.1A sunset provision (stating the direction in para 5.1 ceases to be in force at the end of 1 December 2031) appears in the current text and reflects amendment history recorded in the table.
• Technical calibration and accreditation details. Para 4.3A, which specifies what makes a certificate of calibration or verification valid and which accredited organisations qualify, is shown in the compilation as added by F2018L00961. This links CAO practice with national calibration and accreditation regimes.

Practical implications of the amendment history

• Evolution toward delegation and accreditation. The amendment record shows a movement toward incorporating national measurement accreditation criteria, a defined role for CASA in approving non‑weight control officer persons to weigh aircraft (para 4.1A), and refined fleet sampling and validation mechanisms. The Table of Amendments documents these alterations and identifies the instruments that effected them.

Documentary record

• The compilation number and dates. This is Compilation No. 3 prepared on 2 June 2023 taking into account amendments up to the Civil Aviation Order 100.7 Amendment Instrument 2023 and noting in the Table of Orders that the 2023 amendment commenced 12 May 2023. The Table of Amendments itemises the precise provisions affected and how they were changed.

For legal advising or compliance work, users should refer to the specific amending instrument texts (F2018L00961, F2021L01680, F2023L00532) for exact amendment wording and chronology, and consult the register entries for commencement details. The CAO compilation itself is the authoritative consolidated text as at the compilation date and lists the amending instruments that produced the current wording.

The Civil Aviation Order 100.7 Instrument 2015 compilation provided here does not include any court or tribunal decisions. The instrument itself does not cite or summarise litigation. The text names no cases and the Table of Amendments records only legislative and instrument amendments, not judicial developments.

Practical consequences of the absence of a litigation record in the instrument

• No judicial gloss within the instrument. Because the CAO text as compiled does not contain any references to judicial interpretation, applying the instrument in contested circumstances will require practitioners to search external sources of case law, tribunal decisions, CASA enforcement decisions and administrative determinations that apply or interpret CAO 100.7. The absence of cases in the instrument itself does not mean none exist; it means the CAO compilation does not record them.
• Necessity of independent legal research. For questions of statutory construction, enforcement outcomes, the scope of CASA’s powers under paras 3.1(3) and 6.5, or the evidentiary weight of load data and weighing summaries, practitioners should search litigation databases, CASA published decisions, and the administrative law record for relevant decisions that interpret CAO 100.7 or the underlying CAR/CASR/Act provisions referenced in the CAO.
• Points likely to have generated dispute. Based on the provisions, likely areas where litigation or administrative disputes might arise include: CASA’s exercise of its discretion to require weighings under para 3.1(3) or 6.5; the validity of load data prepared by validation under para 3.5 rather than by physical weighing; disputes over inclusion or exclusion of aeroplanes in fleets and the application of para 3A.5 deviation limits; the adequacy of scale calibration certificates under para 4.3/4.3A; and the sufficiency of operator record‑keeping under Part 6. These potential dispute zones are predictable from the CAO’s technical rules, but the CAO itself does not supply case law to clarify them.

Recommendation for practitioners

• Check current case law and CASA guidance. Because the CAO is technical and interacts with CASA discretionary enforcement power, practitioners and compliance officers should consult CASA guidance materials such as the publication "Weight Control of Aircraft" mentioned in para 7.1 as providing guidance on acceptable methods, and should search for CASA administrative decisions and court cases that have addressed the interpretation, evidential requirements or limits of CAO 100.7. The CAO compilation is a necessary starting point but insufficient for assessing litigation risk without external judicial and administrative records.

In short, there is no litigation history recorded in the CAO compilation itself. Practitioners should undertake external case law and administrative decision research to find any judicial or tribunal interpretation relevant to CAO 100.7.

CAO 100.7 contains multiple technical details and conditional exceptions where non‑compliance can easily arise if practitioners only read the headline rules. Below are practical "gotchas" drawn directly from the instrument that operators, maintenance organisations, pilots and compliance officers commonly need to watch for.

1. Private aircraft cannot be used commercially if out of date

• If an aircraft used in private operations has not been reweighed or had its weight validated at the interval applicable under para 3.2, it must not be used in commercial operations (para 3.3). Operators must endorse logbooks and load data sheets with the precise wording in para 3.4: "THIS AIRCRAFT IS RESTRICTED TO PRIVATE OPERATIONS UNTIL IT HAS BEEN WEIGHED IN ACCORDANCE WITH CAO 100.7." Failure to apply the endorsement is itself a breach of the CAO.

2. Validation is limited to specific types and requires documentary checks

• For aircraft types listed in items 3 and 4 of the para 3.2 table, a weight control officer may validate weight using the previous weighing summaries and the logbook record (para 3.5). But the officer must examine the aircraft and logbook and the immediately preceding weighing summary and equipment list and may only declare records accurate where they are complete. Validation is not automatic; it is an evidential judgment that must be recorded both on the load data sheet and in the aircraft’s logbook noting that the load data sheet was prepared by validation rather than weighing (para 3.5(c)-(d)). Treat validation as a procedural right requiring documentary sufficiency.

3. Fleet averaging has tight inclusion and correction rules

• You cannot include an aeroplane in a fleet unless it has been weighed within the previous 4 years (para 3A.3). Inclusion also has deviation tests: an aircraft’s actual operating weight must not vary from the fleet average by more than 0.5% of maximum landing weight, and actual CG must not vary by more than 0.5% of mean aerodynamic chord unless the aircraft is operated individually or adjustments are made (para 3A.5-3A.8). Operators that try to include aircraft with accountable physical differences must make explicit corrections when calculating weights or CG for that aeroplane (para 3A.8). If an operator omits an aeroplane from a fleet and does not include it elsewhere, it must operate that aeroplane using individual weight and CG and reweigh in accordance with para 3.2 (para 3A.9). Failure to follow these rules can result in improper loading calculations for individual aircraft.

4. Sample sizes and selection rules are prescriptive

• Re‑establishing fleet values every 4 years requires sample weighing of a minimum number of aeroplanes in the fleet as set out in para 3B.2. For fleets larger than 23 aeroplanes the minimum is calculated as 6 plus 10% of the number of aeroplanes over 9, rounded up for decimals. Operators must select the aeroplanes that have not been weighed for the longest time when doing the sampling (para 3B.4). Operators who attempt to game sampling by repeatedly weighing the same subset can breach the "select the longest not weighed" rule.

5. Scales calibration and certificate details are exacting

• Scales must be calibrated within the last 12 months by the manufacturer, a National Measurement Institute approved organisation, or an organisation using a reference standard with a valid certificate (para 4.3). Para 4.3A clarifies that a certificate is valid during a stated period or until a stated recalibration date and specifies recognised accreditation bodies. Using a calibration certificate that is out of date or from an unlisted accreditor will make the weighing non‑compliant.

6. Two independent weighings and tolerance bands are mandatory

• Empty weight and empty weight CG must come from two consecutive and independent weighings with the load removed between weighings (para 4.5). If the first two differ by more than 0.2% of the mean weight or 10 kg, whichever is greater, additional weighings must be done until two agree within tolerances (para 4.6). This places an operational requirement on weighing facilities and personnel to control procedures and to reweigh until the tolerance is satisfied.

7. Load data renewal thresholds differ between aeroplanes and rotorcraft

• The thresholds triggering load data renewal after modifications vary. For aeroplanes the empty weight change trigger is more than 0.5% of MTOW or 10 kg and CG change trigger is more than 2% of the CG range or 5 mm; for rotorcraft the empty weight trigger is more than 1% of MTOW or 10 kg and CG change trigger is more than 10 mm or 10% of the CG range, whichever is the lesser (para 6.3). Practitioners must apply the correct set of thresholds to avoid under‑ or over‑reacting to modifications.

8. Placarding is only available for small MTOW aircraft

• The loading system for aircraft with MTOW 5 700 kg or less may be expressed on placards if the information can be readily set out in placard form (para 5.2(2A)). For larger aircraft or where the loading system is complex, a placard approach is not permitted.

9. Duplicate copies must be held on the ground

• The owner or operator must keep duplicate copies of all current approved loading data "in a safe place on the ground" (para 5.2(5)). Failure to maintain duplicates undermines the operator’s ability to produce evidence of compliance and may be actionable.

10. CAO 100.7 ties into other regulations and CASA approvals

• Several provisions require CASA approval or draw in national measurement accreditation. For example, para 4.1A tasks CASA with approving aircraft weighing procedures courses; para 4.3 and 4.3A specify acceptable calibrators and accreditations; and para 5.2(3) gives weight control officers an approval role for loading data. Operators should not treat the CAO as autonomous; compliance often requires CASA approvals.

11. Sunset of para 5.1 direction

• Para 5.1A records that the direction in para 5.1 ceases at the end of 1 December 2031. Operators relying on para 5.1’s specific direction should note the sunset date and the need to track any further amendments or replacement directions.

These are concrete compliance traps and operational details that must be managed by operators, maintenance organisations and compliance teams. The instrument sets precise technical and documentary parameters; noncompliance typically arises from procedural slippage, failing to hold up‑to‑date calibration certificates, misunderstanding fleet inclusion rules, or improper certification by persons lacking the requisite approvals or training.

Below is a pragmatic checklist and compliance framework, structured around the CAO’s key obligations, with references to the specific CAO provisions that impose each duty. Use this as the basis for a compliance programme, audit checklist or operational procedure.

1. Identify whether CAO 100.7 applies to your aircraft

• Check the Application exclusions (start of the instrument). Balloons, airships and certain sport‑administered aircraft may be excluded where CASA has accepted or approved other procedures. For sailplanes and ASAO‑administered aircraft, verify whether the sport body’s weighing procedures have CASA acceptance (Application (a)-(e)).

2. Initial weighing and records before issue of certificate of airworthiness

• Ensure each aircraft (except where para 3.1(2) applies) is weighed before initial issue of a certificate of airworthiness (para 3.1(1)). If relying on other methods to establish empty weight and empty weight CG, obtain the written satisfaction of a weight control officer or a person referred to in para 4.1A to document the waiver (para 3.1(2)).

3. Determine applicable reweigh or validation intervals

• For commercial operations, consult the table in para 3.2 to schedule re‑weighs or validations by aircraft type and MTOW. For operators who want to use fleet values, apply subsections 3A and 3B to establish eligibility and sampling schedules. Remember: fleet members must have been weighed within the previous 4 years (para 3A.3) and fleet values must be re‑established at least every 4 years (para 3B.1).

4. Document a fleet procedure if using fleet (weight and CG) values

• Prepare written procedures specifying how fleet values are established, reviewed and used, how fleet members are identified, and how the operator will comply with subsections 3A and 3B (para 3A.4). Ensure sample selection follows para 3B.4 by selecting the aeroplanes not weighed for the longest time.

5. Engage qualified personnel for weighings and ensure certification

• Confirm that weighings are supervised by a weight control officer whose appointment covers the activity, or that the person performing weighings meets para 4.1A training and practical experience requirements. Maintain documentary evidence of weight control officer appointments and of any CASA‑approved course completions under para 4.1A.

6. Prepare and follow a written weighing procedure and ensure equipment compliance

• Use scales meeting the accuracy tolerance in para 4.2 and ensure scales have valid calibrations performed within the previous 12 months by acceptable bodies per para 4.3 and 4.3A. Retain calibration certificates for the scales and any reference standards used. Provide sufficient personnel and equipment to carry out weighings (para 4.4).

7. Execute weighings to the CAO standard

• Perform two consecutive and independent weighings with the load completely removed between weighings (para 4.5). If the first two differ by more than 0.2% of mean weight or 10 kg, continue weighings until two consecutive results agree within tolerance (para 4.6). Record weighings in an aircraft weighing summary approved by CASA and ensure the empty weight and empty weight CG are certified by the weight control officer or para 4.1A person (para 4.7).

8. Prepare, approve and retain load data sheets and loading systems

• Prepare a load data sheet for each aircraft showing empty weight and empty weight CG, and operating weights if used, together with lists of removable equipment and disposable loads (para 5.2(1)). Prepare a loading system unless the operator can show the aircraft cannot be loaded outside approved limits while observing seating constraints (para 5.2(2)). Seek approval of loading data from a weight control officer where the CAO contemplates it (para 5.2(3)). Keep duplicate copies of all current approved loading data in a safe place on the ground (para 5.2(5)). For small aircraft (MTOW ≤ 5 700 kg) consider placard placarding if the loading system can be readily summarised on placards (para 5.2(2A)).

9. Maintain continuous records of weight alterations and amend load data when triggers are exceeded

• Maintain a complete, continuous record of changes in empty weight and empty weight CG and, if applicable, operating weight and operating weight CG for each aircraft (para 6.1). Raise a new record after each weighing (para 6.2). Renew load data whenever modifications or records indicate changes exceeding the thresholds in para 6.3. If CASA considers weight control inadequate, be prepared for CASA to require reweighing and to produce weighing records and documentation (para 6.5).

10. Ensure pilots receive and verify loading data evidence before flight

• When loading data prepared under the CAO and approved by CASA applies, ensure the pilot in command receives evidence and takes necessary action to verify compliance before commencing flight (para 5.1). Implement pre‑flight check processes and retention of evidence forms or signatures to show pilots received and verified loading data.

11. Monitor regulatory approvals, calibration certificates and CASA interactions

• Track expiry dates and reaccreditation schedules for scale calibrations (para 4.3 and 4.3A). Maintain records of CASA approvals and any CASA guidance that addresses acceptable weight control methods. Be prepared to produce weighing summaries approved by CASA and other documentary evidence if CASA invokes para 3.1(3) or para 6.5.

12. Audit and training

• Audit compliance with fleet inclusion thresholds, sample selection, weighing tolerances and load data renewals periodically. Train personnel on the CAO’s technical specifications, the requirement for two independent weighings, calibration certificate validation, logbook endorsements for private aircraft awaiting reweighs (para 3.4), and the pilot pre‑flight evidence obligations.

13. Track changes and sunset dates

• Monitor amendment history and expiry or sunset provisions. Para 5.1A records that the direction in para 5.1 ceases at the end of 1 December 2031. Stay current with CASA publications, the Civil Aviation Orders register and the underpinning CAR/CASR provisions tied to the CAO.

Checklist summary (immediate practical actions)

• Confirm CAO applies and list excluded aircraft per Application section.
• Schedule initial and periodic weighings per para 3.2 table and fleet schedule under 3A/3B.
• Use CASA‑approved or weight control officer‑supervised weighings; record in CASA‑approved weighing summary.
• Ensure scales and calibration certificates meet 4.2, 4.3 and 4.3A.
• Maintain continuous weight alteration records and duplicate load data copies on the ground.
• Implement pilot verification procedures per para 5.1 and ensure logbook endorsements per para 3.4 for restricted aircraft.
• Institute internal audits and training and keep a compliance calendar aligned to reweigh/validation and calibration due dates.

Following the CAO’s prescriptive technical requirements and CASA approval pathways will materially reduce regulatory risk. Where procedural discretion exists, such as fleet averaging or validation, document the basis for the operator’s choice and retain the evidence that the operator followed the CAO’s selection, sampling and correction rules (subsections 3A and 3B and para 3.5).