Explanatory Statement
Civil Aviation Act 1988
Civil Aviation Order 108.56 Repeal Instrument 2013
Purpose
The purpose of Civil Aviation Order 108.56 Repeal Instrument 2013 (the CAO repeal instrument) is to repeal Civil Aviation Order (CAO) 108.56. This has become redundant following the consolidation in Civil Aviation Order 100.5 Amendment Instrument 2013 (No. 1) (the CAO 100.5 amendment) of uniform maintenance requirements for barometric altimeters, and modified versions of CAO 108.56 testing requirements for these and other similar instruments, including pitot-static systems, air data computers, airspeed indicators, and fuel quantity gauges. Since the sole purpose of the CAO repeal instrument is to repeal CAO 108.56 because of this amendment to CAO 100.5, the remainder of this Explanatory Statement explains the CAO 100.5 amendments to provide context for the CAO 108.56 repeal.
The revised standards for altimeters are needed to eliminate the unacceptable risks associated with the previous airworthiness directives (ADs) which offered 2 alternative standards. These could result in different aircraft flying in the same airspace but operating with equipment maintained to different maintenance standards and potentially broadcasting inaccurate altitude data with risks to the capacity of air traffic control to ensure appropriate aircraft separation.
The revised standards for pitot-static systems, air data computers, airspeed indicators, and fuel quantity gauges are modified forms of the previous standards that were located in CAO 108.56 but which are now consolidated with the altimeter maintenance standards in CAO 100.5. CAO 108.56 is consequentially repealed.
The standards are in the form of instrumentation testing requirements, the test procedures to be followed, the standards that the relevant instrumentation is to meet, the intervals to be observed between tests and the associated occasions for some tests.
Legislation
Section 98 of the Civil Aviation Act 1988 (the Act) empowers the Governor-General to make regulations for the Act and the safety of air navigation.
Under subregulation 38 (1) of the Civil Aviation Regulations 1988 (CAR 1988), CASA may issue directions relating to the maintenance of Australian aircraft.
Under regulation 5 of CAR 1988, CASA may, among other things, issue a direction in Civil Aviation Orders (the CAOs).
CAO 100.5 contains general directions relating to the maintenance of Australian aircraft in respect of which an Australian certificate of airworthiness is in force.
CAO 108.56 contained general directions setting out test procedures and accuracy requirements for airspeed indicators, pressure-type altimeters, pitot-static systems and fuel quantity gauges.
Under subsection 33 (3) of the Acts Interpretation Act 1901, the power to make a legislative instrument is construed as including the power to repeal it in the same manner as it was made.
Background
Aircraft pilots use barometric altimeters as the primary means of monitoring and measuring their desired altitude. Barometric altimeters measure ambient air pressure (static pressure) and display units of height. These instruments, whether aneroid based or solid state, must be checked on a regular basis to ensure that what is displayed to the pilot is accurate. Such accuracy is particularly critical during approach and departures where there are terrain obstacles in close proximity.
CASA considered that previous checking requirements, contained in several ADs (to be cancelled in a separate procedure), were unsatisfactory because instead of a uniform altimeter maintenance standard, including simultaneous maintenance of other related instruments or instrument systems, they offered alternative standards under which related instruments or instrument systems might not be simultaneously maintained, resulting in a potential degrading of overall instrumentation accuracy.
The previous requirements could also give rise to conflicting maintenance standards for aircraft operating under the Visual Flight Rules (VFR) or the Instrument Flight Rules (IFR) but in the same airspace, creating a worst-case potential for loss of separation between aircraft. Accuracy of aircraft altitude information, whether VFR or IFR, broadcast for Air Traffic Control (ATC) purposes via a Mode C transponder, has become all the more critical with the introduction of Wide Area Multilateration (WAM) ATC systems in the Sydney area (SYDWAM) as well as Tasmania (TASWAM).
CAO amendment
The CAO 100.5 amendment resolves these issues by adding a new subsection 11 to CAO 100.5, directing that the registered operator of an Australian aircraft must comply with, and ensure compliance with, each additional maintenance requirement set out in Appendix 1 of CAO 100.5, as it applies to or for the aircraft. The revised requirements do not apply to exempted aircraft.
An exempted aircraft is defined in Appendix 1 as an aircraft with an approved system of maintenance (SOM) under regulation 42M of CAR 1988, or with a maintenance schedule under regulation 41 of CAR 1988, provided the SOM or the schedule incorporates the manufacturer’s instructions for the continuing airworthiness of all instruments and instrument systems fitted to the aircraft.
For non-exempt aircraft, the new Appendix creates a revised uniform and comprehensive standard for the maintenance of barometric altimeters.
In doing so, the Appendix also creates a revised uniform and comprehensive standard for the maintenance of certain related and other instrumentation in the form of pitot‑static systems, air data computers, airspeed indicators, and fuel quantity gauges. The standards for these instruments are modified forms of the standards that were previously contained in CAO 108.56 specifying testing of certain aircraft instruments. CASA considers that it is preferable to locate all of these relevant standards, including for altimeters, in a single CAO, namely CAO 100.5 and to withdraw CAO 108.56.
Repeal instrument
To this end, the CAO repeal instrument repeals CAO 108.56 (Civil Aviation Order 108.56 Repeal Instrument 2013).
The revised testing standards, intervals and procedures for altimeters, pitot-static systems, air data computers, airspeed indicators, and fuel quantity gauges are, by definition, technical and detailed, and even more detailed testing procedures for these instruments are also set out in an Attachment to the CAO Appendix.
Legislative Instruments Act 2003 (LIA 2003)
Under subsections 98 (5) and 98 (5AAA) of the Act, where the regulations provide for certain instruments to be issued in the form of CAOs, such CAOs are legislative instruments. As noted above, under regulation 5 of CAR 1988, CASA may issue regulation 38 directions in CAOs. The CAO repeal instrument is, therefore, a legislative instrument and it is subject to registration, and tabling and disallowance in the Parliament, under sections 24, and 38 and 42, of the LIA 2003.
Gazettal
Under subregulation 38 (2) of CAR 1988, a maintenance direction is not binding on a person unless it has been served on the person. Under subregulation 5 (3) of CAR 1988, when a direction to a person is contained in a CAO, it is taken to have been served on the person on the date on which the making of the CAO was notified in the Gazette.
Under subsection 56 (1) of the LIA 2003, if certain enabling legislation requires the text of a legislative instrument, or particulars of its making, to be published in the Gazette, such requirements are taken to be satisfied when the instrument is registered.
This facilitative provision for registration to take the place of gazettal does not appear to cover the specific case of the service requirements under subregulations 38 (2) and 5 (3) of CAR 1988. Therefore, to avoid doubt, the CAO repeal instrument was also gazetted on the day on which it commenced, that is, 1 August 2013.
Consultation
Consultation under section 17 of the LIA was undertaken as follows. A Notice of Proposed Rule Making (NPRM) for the CAO 100.5 amendment proposals was published by CASA on its website and by broadcast email, on 7 September 2011, inviting comments from the public and aviation industry generally up until 4 November 2011. The NPRM set out proposals for the testing and ongoing maintenance of certain aircraft instrument systems, and the cancellation of the previously relevant ADs.
CASA considered that responses received to its NPRM were from a representative cross-section of the aviation industry, including the Aircraft Operators and Pilots Association, the Gliding Federation of Australia and the Australian Ballooning Federation. Qantas, Virgin Australia and Skywest, together with other individuals contributed to the final total of 140 responses.
Some respondents expressed concern about CASA cancelling the previous ADs and embodying the revised maintenance requirements in a CAO. However, CASA considers that a CAO is a more appropriate, effective and enforceable vehicle for the revised requirements to be broadcast and implemented. Some respondents also urged CASA to retain the previous system of dual maintenance standards for altimeters. However, CASA considers that retention of 2 standards would continue to give rise to greater aviation safety risks, particularly for aircraft separation as noted above.
CASA responded to the comments made by some respondents by clarifying its proposals regarding the applicability of the revised standards to aircraft fitted with modern computer-based systems. Overall, the majority of respondents to the NPRM consultation (approximately 60%) indicated support for the proposals either unchanged or with minor amendments which CASA took into account.
Statement of Compatibility with Human Rights
The Statement in Appendix 1 is prepared in accordance with Part 3 of the Human Rights (Parliamentary Scrutiny) Act 2011. The CAO repeal instrument does not engage any of the applicable rights or freedoms, and is compatible with human rights, as it does not raise any human rights issues.
Office of Best Practice Regulation (OBPR)
A Regulation Impact Statement (RIS) for the CAO 100.5 amendment was not required (OBPR id: 14831) and, therefore, a RIS was not required for the CAO repeal instrument.
Making and commencement
The CAO repeal instrument has been made by the Director of Aviation Safety, on behalf of CASA, in accordance with subsection 73 (2) of the Act.
The CAO repeal instrument commences on 1 August 2013.
[Civil Aviation Order 108.56 Repeal Instrument 2013]
Appendix 1
Statement of Compatibility with Human Rights
Prepared in accordance with Part 3 of the
Human Rights (Parliamentary Scrutiny) Act 2011
Civil Aviation Regulations 1988
Civil Aviation Order 108.56 Repeal Instrument 2013
This legislative instrument is compatible with the human rights and freedoms recognised or declared in the international instruments listed in section 3 of the Human Rights (Parliamentary Scrutiny) Act 2011.
Overview of the legislative instrument
The purpose of Civil Aviation Order 108.56 Repeal Instrument 2013 (the CAO repeal instrument) is to repeal Civil Aviation Order (CAO) 108.56. This has become redundant following the consolidation in Civil Aviation Order 100.5 Amendment Instrument 2013 (No. 1) of uniform maintenance requirements for barometric altimeters, and modified versions of CAO 108.56 testing requirements for these and other similar instruments, including pitot-static systems, air data computers, airspeed indicators, and fuel quantity gauges. The sole purpose of the CAO repeal instrument is to repeal CAO 108.56 because of this amendment to CAO 100.5. The revised standards in CAO 100.5 for altimeters are needed to eliminate the unacceptable risks associated with the previous airworthiness directives which offered 2 alternative standards and maintenance intervals. These could result in different aircraft flying in the same airspace but operating under different maintenance requirements and potentially broadcasting inaccurate altitude data with risks to the capacity of air traffic control to ensure appropriate aircraft separation. The revised standards for pitot-static systems, air data computers, airspeed indicators, and fuel quantity gauges are modified forms of the previous standards that were located in CAO 108.56 but which are now consolidated with the altimeter maintenance standards in CAO 100.5. CAO 108.56 is consequentially repealed. The standards are in the form of instrumentation testing requirements, the test procedures to be followed, the standards that the relevant instrumentation is to meet, the intervals to be observed between tests and the associated occasions for some tests. These are fundamental aviation safety requirements that do not impinge on human rights or freedoms.
Human rights implications
The CAO repeal instrument is compatible with the human rights and freedoms recognised or declared in the international instruments listed in section 3 of the Human Rights (Parliamentary Scrutiny) Act 2011. The instrument does not engage any of the applicable rights or freedoms.
Conclusion
This legislative instrument is compatible with human rights as it does not raise any human rights issues.
Civil Aviation Safety Authority