Explanatory Statement
Civil Aviation Safety Regulations 1998
Exemption — precision runway monitor system standards
Purpose
The purpose of this instrument is to exempt Airservices Australia (AA) from having surveillance radar of a particular specification when controlling parallel runway approaches to Sydney airport in instrument meteorological conditions.
Legislation
Subsection 98 (1) of the Civil Aviation Act 1988 (the Act) provides that the Governor-General may make regulations for the Act and in the interests of the safety of air navigation.
Legislation — Part 172 of CASR 1998
Part 172 of the Civil Aviation Safety Regulations 1998 (CASR 1998) sets out the requirements and conditions for a person to be approved, and continue as, an air traffic service (ATS) provider.
Under subregulation 172.275 (1) of CASR 1998, if CASA approves an applicant as an ATS provider, CASA must give the applicant a certificate setting out the scope, duration and conditions of the approval.
Under regulation 172.022 of CASR 1998, CASA may issue a Manual of Standards (MOS) — Part 172, setting out standards and procedures for ATS providers.
Under subregulation 172.065 (1) of CASR 1998, an ATS provider must ensure that any ATS that it provides is provided in accordance with MOS Part 172 and relevant standards set out in Annex 11 of the Chicago Convention.
Under subregulations 172.095 (1) and (2) of CASR 1998, an ATS provider must, at all times, make available for use by its personnel the equipment and facilities necessary for providing, in accordance with the standards set out in MOS Part 172, the services covered by its ATS approval, including equipment of the kind specified in the MOS Part 172.
Section 10.4 of MOS Part 172 deals with Departures and Arrivals. Subsection 10.4.2 contains requirements for the conduct, in instrument meteorological conditions (IMC), of independent parallel approaches to parallel runways with centrelines separated by more than 1 035 m.
Paragraph 10.4.2.1 (a) of MOS Part 172 deals with runways separated by more than 1 525 m which is not relevant in this case as the parallel runways at Sydney airport have a lesser separation.
Paragraph 10.4.2.1 (b) of MOS Part 172 specifies in particular that for runways separated by more than 1 035 m but less than 1 525 m, a suitable surveillance radar must be available with a minimum azimuth accuracy of 0.6 degrees (1 sigma) and update period of 2.5 seconds or less.
Paragraphs 10.4.2.1 (c) to (m) of MOS Part 172 set out essential requirements that complement the surveillance radar requirement. For example, that the relevant aircraft must be using straight-in approaches; that instrument landing system (ILS) approaches must be conducted to both runways; that a minimum radar separation (1 000 ft or 3 NM) is provided until aircraft are established on the ILS localiser course, at which time a minimum of 1 000 ft vertical separation or 2 NM radar separation must be provided. A full list of these essential requirements is in Appendix 1.
Legislation — exemptions
Under subregulations 11.160 (1) and (2) of CASR 1998, CASA may grant an exemption from compliance with a provision of CASR 1998 to a person or class of persons. CASA must regard as paramount the preservation of an acceptable level of aviation safety. Details of CASA’s exemption power are set out in Appendix 2.
Background
AA holds a certificate of approval issued by CASA under regulation 172.275 of CASR 1998 to provide ATS and is, therefore, an approved ATS provider subject to the requirements of Part 172 of CASR 1998 and MOS Part 172.
AA currently controls independent parallel approaches in IMC at Sydney airport using surveillance radar equipment known as precision runway monitor (PRM).
AA wishes to upgrade the current PRM and proposes, therefore, to replace it with a wide area multilateration PRM (WAM PRM).
AA submitted a comprehensive safety case to CASA for the introduction of WAM PRM. The safety case argued that WAM PRM is a safe, suitable and appropriate replacement for the current PRM.
WAM PRM
WAM PRM uses a different technique from current PRM for detecting aircraft and determining their position in relation to the correct approach path. Because of this different technique, WAM PRM cannot comply with the particular equipment requirements in paragraph 10.4.2.1 (b) of MOS 172.
On the basis of the safety case, AA has requested an exemption from the paragraph 10.4.2.1 (b) standard for a PRM in order to commence operations at Sydney using the WAM PRM.
CASA consideration
CASA has reviewed the AA safety case, in light of its knowledge that similar systems are already satisfactorily in service in the United States of America. CASA has, therefore, accepted the safety case argument for the introduction of WAM PRM at Sydney airport.
However, the exemption is subject to a number of conditions. In particular, AA must operate the WAM PRM in accordance with the particulars of the safety case and its supporting documents as submitted to CASA and on the basis of which CASA issued the exemption. AA must also comply with all other paragraphs of section 10.4.2 of MOS 172 (other than paragraph (b)) relating to independent parallel approaches in IMC.
Post-implementation review (PIR)
CASA also understands that AA will be conducting a PIR of the WAM PRM arrangement 90 days after commissioning. CASA will review this PIR with a view to reconsidering the exemption or extending it as appropriate. In addition, through monitoring of day-to-day incident reporting, relevant CASA officers can and will take any necessary action to address deficiencies in the arrangement or the exemption instrument.
Exemption
The exemption, therefore, exempts AA from the requirements under CASR 1998 relating to the surveillance system that must be used for independent parallel approaches in IMC to parallel runways that are separated by less than 1 525 metres.
The exemption will operate until the end of 23 June 2013, unless reviewed and withdrawn or extended before that date. Further details of the exemption are set out in Appendix 3.
Legislative Instruments Act
Under subparagraph 6 (d) (i) of the Legislative Instruments Act 2003 (the LIA), an instrument is a legislative instrument for section 5 of the LIA if it is declared to be a disallowable instrument under legislation in force before the commencement of the LIA. Regulation 11.215 of CASR 1998 declares an exemption of this kind to be a disallowable instrument. The exemption is, therefore, a legislative instrument and it is subject to registration, and tabling and disallowance in the Parliament, under sections 24, 38 and 42 of the LIA.
Consultation
Consultation under section 17 of the LIA was carried out with AA on the basis of the safety case proposed to ensure the safety of the proposed arrangement. Subject to certain conditions, the exemption is beneficial in that it relieves of an obligation.
Office of Best Practice Regulation (OBPR)
The exemption is of beneficial effect. OBPR does not require preparation of a Regulation Impact Statement in this case because a preliminary assessment of business compliance costs in the context of the nature of the instrument indicates that it will have only a nil to low impact on business.
Commencement and making
The exemption commences on 24 June 2011 after it is registered and stops having effect at the end of 23 June 2013. The exemption has been made by the Director of Aviation Safety, on behalf of CASA, in accordance with subsection 73 (2) of the Act.
Retrospectivity
The draft exemption was signed by the Director of Aviation Safety in Brisbane on 22 June 2011 and despatched to Canberra, for registration on or before 24 June 2011. However, as a result of the disruption of airline flights caused by ash from the Puyehue‑Cordon Caulle volcanic complex in southern Chile, the signed exemption was not received in Canberra until late on 27 June 2011 and registered on 28 June 2011.
Since it was expressed to commence on Friday, 24 June 2011, the exemption is, therefore, inadvertently, retrospective in effect.
Subsection 12 (2) of the LIA provides that a legislative instrument has no effect if it would take effect before the date it is registered and as a result the rights of a person at the date of registration (other than the Commonwealth) would be affected so as to disadvantage that person, or liabilities would be imposed on a person (other than the Commonwealth) in respect of anything done before the date of registration.
The exemption is beneficial in that it relieves of an obligation. It does not prejudice the rights of any person as at the date of registration, nor impose liabilities on a person that were not in existence before registration.
[Instrument number CASA EX65/11]
Appendix 1
Essential requirements for the conduct, in IMC, of independent parallel approaches — parallel runways with centrelines separated by more than 1 035 m
For runways separated by less than 1 525 m:
1 a No-Transgression Zone (NTZ) is depicted on the radar display. The NTZ is 610 m wide and is established equidistant between runway centre-lines, beginning from the point where adjacent aircraft first lose vertical separation, and extends to 0.5 NM beyond the farthest Departure End of Runway (DER); and
2 the aircraft are making straight-in approaches; and
3 Instrument Landing System (ILS) approaches are being conducted to both runways; and
4 a minimum of 1 000 ft vertical or 3 NM radar separation is provided until aircraft are established on the ILS localiser course; and
5 when aircraft are established on the ILS localiser course, a minimum of 1 000 ft vertical separation or 2 NM radar separation must be provided between aircraft on adjacent localiser until the higher aircraft reaches the ILS PRM glide path intercept point; and
6 aircraft established on the same ILS localiser course are radar separated by a minimum of 3 NM unless increased longitudinal separation is required due to wake turbulence; and
7 the missed approach track for 1 approach diverges by at least 30 degrees from the missed approach track of the adjacent approach; and
8 when radar vectoring an aircraft to intercept the ILS localiser course, ensure the final vector permits the aircraft to intercept at an angle not greater than 30 degrees and provide for at least 1 NM straight flight prior to ILS localiser course intercept; and
9 the aircraft are cleared to descend to the appropriate glide path intercept altitude soon enough to provide a period of level flight to dissipate excess speed; and
10 if required, the pilot is advised of the altitude to be maintained until the ILS PRM glide path intercept point; and
11 the aircraft are established on the respective aerodrome control frequency and monitoring the relevant PRM frequency no later that 2 NM prior to the higher ILS PRM glide path intercept point.
Appendix 2
Details of CASA’s exemption power under CASR 1998
Under subregulations 11.160 (1) and (2) of CASR 1998, CASA may grant an exemption from compliance with a provision of CASR 1998 to a person or class of persons.
Under subregulation 11.160 (3), CASA may grant an exemption of its own initiative.
Under subregulation 11.170 (3), in deciding whether to grant an exemption, CASA must regard as paramount the preservation of an acceptable level of aviation safety.
Under subregulation 11.205 (1), CASA may impose conditions on an exemption if this is necessary in the interests of the safety of air navigation.
Under regulation 11.210, it is a strict liability offence to fail to comply with a condition of an exemption.
Under regulation 11.215, an instrument granting an exemption is a disallowable instrument for section 46A of the Acts Interpretation Act 1901.
Under regulation 11.225, an exemption must be published on the internet.
Under subregulation 11.230 (1), an exemption ceases on the day specified within it (but no longer than 2 years after its commencement) or, if no day is specified, 2 years after commencement.
Appendix 3
Exemption — precision runway monitor system standards
1 Duration
Under this section, the exemption instrument commences on 24 June 2011 and stops having effect at the end of 23 June 2013.
2 Application
Under this section, the instrument applies to AA in its capacity as an ATS provider controlling independent parallel approaches in IMC at Kingsford Smith aerodrome, Sydney (the aerodrome).
3 Exemption
Under this section, AA is exempt from subregulation 172.065 (1), and subregulations 172.095 (1) and (2), of CASR 1998, to the extent that each subregulation requires compliance with the requirements in paragraph 10.4.2.1 (b) of the Manual of Standards (MOS) — Part 172 (the MOS).
4 Conditions
Under this section, the exemption is subject to the conditions mentioned in Schedule 1.
Schedule 1 Conditions
Schedule 1 sets out conditions for the exemption to apply and continue to apply.
1Under clause 1, when using runways separated by less than 1 525 m for independent parallel approaches in IMC at the aerodrome, a WAM PRM system must be used.
2Under clause 2, the WAM PRM system must be operated in accordance with the AA document All Phases Safety Case Sydney Precision Runway Monitor System Replacement, and its supporting documents, as submitted to CASA on 18 May 2011.
3Under clause 3, for controlling independent parallel approaches in IMC using the WAM PRM system, AA must ensure that each of the applicable paragraphs of section 10.4.2 of the MOS (other than paragraph (b)) is complied with.