Changes to aircraft weight and balance requirements- Consultation draft CAO 100.7 (CD 1603OS)

Closed 19 Apr 2018

Opened 5 Apr 2018

Results updated 6 Mar 2019

CASA received a total of eight submissions; six respondents consented to having their comments published on the CASA website.

Summary of feedback

Calibration options

Six of the eight respondents agreed that the options for the calibration were sufficient for industry use. One respondent who answered 'not applicable' subsequently did not provide any comment and one disagreed with the proposed paragraph changes.

Interval extension

Three of eight respondents agreed with the extension of the duration interval for calibration of scales without comment. Three respondents agreed, but with proposed modifications or clarifications. One respondent who answered 'not applicable' subsequently did not provide any comment and one disagreed with the proposed changes.

One respondent that agreed with a modification or clarification suggested the ability to extend the calibration interval, 'provided the history of past calibration results show no fluctuations or long-term drift in the error figures'.

The respondent who disagreed with the proposal stated, 'there was not sufficient evidence to extend the calibration period to two years'.

Additional comment

A respondent pointed out that there was a mistake in the reference to the National Measurement Institute, mistakenly written as the 'National Measurements Institute'.

Next steps

CASA has corrected the CAO 100.7 Amendment to reflect the correct term for the National Measurement Institute.

CASA believes that the available options for calibration of scales are adequate and provide flexibility for industry to be able to effectively calibrate weighing scales.

CASA continues to support alleviation from the one-year calibration requirement. However, CASA agrees with the comments from the consultation that a time-based extension (from one year to two years) does not consider multiple factors beyond the time between two calibration events, such as usage, equipment types etc.

CASA has not extended the interval at this time. CASA will include this subject in the wider regulatory reform projects.


Published responses

View submitted responses where consent has been given to publish the response.


This consultation draft outlines minor changes to the permitted variation of the centre of gravity (CG) limit of rotorcraft and the calibration requirements for weighing scales in Civil Aviation Order 100.7.

Purpose and scope of the proposed amendments

The current calibration requirements specified in CAO 100.7 are unnecessarily restrictive. They state weighing scales must have been calibrated:

  • by the manufacturer or by a laboratory that is accredited with the National Association of Testing Authorities (Australia) or a similar national accreditation body that is a member of the International Laboratory Accreditation Cooperation
  • within a period of 1 year before the weighing of any aircraft.

For those who carry out the calibration, CASA has been providing additional flexibility via exemptions (see current exemption CASA EX73/17). This amendment would incorporate the intent of the exemptions into the CAO. CASA also proposes to extend the calibration requirement to 2 years or to the calibration period recommended by the manufacturer, whichever is shorter.

This amendment would also correct an error that was introduced in a previous amendment to the CAO. The previous amendment changed the requirement to create a new load data sheet following changes to the empty weight CG for rotorcraft, from the lesser of the specified CG limits to the greater of the limits. This amendment would revert to the former requirement, i.e. the load data sheet must be renewed for a rotorcraft if the empty weight CG has changed by more than 10 mm or 10% of the maximum permissible centre of gravity range, whichever is the lesser (see paragraph 6.3 (b) (ii)).

Finally, this amendment adds a note to allow readers to find appropriate guidance for weight control methods.

Impact on industry

Most of the changes are machinery in nature and will not have an impact on industry. However, the change of time between calibration intervals is expected to reduce burden on industry.

Regulation impact statement

The Office of Best Practice Regulation (OBPR), assessed that the proposed amendment will have a minor or machinery impact and that no further analysis in the form of a Regulation Impact Statement was required (OBPR ID: 20549).

Closing date for comment

CASA will consider all comments received as part of this consultation process and incorporate changes as appropriate. Comments on the Civil Aviation Order 100.7 Amendment Instrument 2018 (No. 1) should be submitted through the online response form by close of business 19 April 2018.

Why your views matter

CASA recognises the valuable contribution that community and industry consultation makes to the regulatory development process.

A copy of the Summary of Proposed Changes and Draft instrument  is provided below. You can read it on this screen or save it to your computer using the popup options.

Please read the documents before providing your feedback in the online survey.

What happens next

At the end of the response period for public comment, we will review each comment and submission received through the online response form. We will make all submissions publicly available on the CASA website unless a respondent requests their submission remain confidential. Information about how we consult and how to make a confidential submission is available on the CASA website.

When the consultation draft submissions are published we will also publish a summary of consultation, which will summarise the feedback received, describe any intended changes and detail our plans to make the rule changes.

If we do change the rules, information about the rule making will be available in the Explanatory Statement that is published with the final rule on the Federal Register of Legislation. You can subscribe to our consultation and rule making mailing list to be notified of future consultation or rule making.


  • CASA Staff
  • Air operators
  • Airworthiness organisations
  • Engineers
  • Manufacturers
  • Pilots


  • Airworthiness / maintenance
  • Operational standards