Explanatory Statement
Civil Aviation Act 1988
Revocation of determination — instrument approach and departure procedures
Revocation of approval — RNAV RNP trial at Queenstown, New Zealand
Revocation
Section 98 of the Civil Aviation Act 1988 (the Act) provides that the Governor-General may make regulations for the Act and the safety of air navigation.
Under subregulation 178 (1) of the Civil Aviation Regulations (CAR 1988), the pilot in command of an aircraft must not fly along a route segment at a height lower than the published lowest safe altitude (LSALT) for that segment. Under subregulation 178 (2), if there is no LSALT, the pilot must not fly lower than the LSALT calculated by a method determined by CASA. However, paragraph 178 (4) (c) provides an exemption from these requirements if the flight is during an instrument approach procedure (IAP) or an instrument departure procedure (IDP) determined by CASA under paragraphs 178 (6) (b) or (c) respectively.
Instrument CASA 166/05, determined an IAP and an IDP for use in a trial being conducted by Qantas Airways Ltd (Qantas). The instrument enabled specially trained pilots in specially equipped Boeing 737-800 aeroplanes to fly into and out of Queenstown, New Zealand using RNAV (RNP) technology and navigation. RNAV refers to the computerised area navigation system, and RNP to the related navigation performance capability of appropriately equipped aircraft.
Use of RNAV (RNP) enables accurate navigation and obstacle avoidance in instrument meteorological conditions (I.M.C.) under the instrument flight rules (I.F.R.). This can significantly reduce the likelihood of accidents involving controlled flight into terrain (CFIT). CFIT can be more likely in complex, non-precision approaches (NPA) which lack vertical guidance and which impose a high mental workload on the flight crew. The safety of flights into and out of Queenstown is affected by the high terrain and lack of accurate approach and departure navigation aids. However, the risks are significantly reduced by the use of instrument approach and departure procedures in RNP-capable aircraft.
On the basis of the data and reports that it has received to date from Qantas concerning the trial, CASA is satisfied that the trial may come to an end. This means that RNAV (RNP) operations at Queenstown may be conducted on a routine basis, in accordance with the limitations and requirements specified in the flight manual of the aircraft, and in compliance with the requirements of the NZ Civil Aviation Authority, without specific limitations mentioned in instrument CASA 166/05. CASA 166/05 is, therefore, revoked.
Approval
Subsections 12 and 12A of Civil Aviation Order 20.7.1B provide for methods of meeting take-off obstacle clearance requirements in relation to take-off weight limitations by reference to the definition of the take-off area. Under subparagraph 12.1.1 (b) and paragraph 12A.5, the limitation of the take-off area is redefined for approved RNP operations, in RNP-capable aeroplanes that are approved for area navigation (RNAV) using specified RNP containment values. For Qantas Queenstown RNAV (RNP) operations, these approvals and specifications were in the instrument which has now been revoked. Therefore, to enable departures during Qantas RNAV (RNP) operations at Queenstown to continue to take advantage of these RNP‑related obstacle clearance provisions, a separate instrument of approval and specification has been made (CASA 582/05).
Legislative Instruments Act 2003
Under subsections 5 (1) and (4) of the Legislative Instruments Act 2003 (the LIA) the revoked determination was a legislative instrument. Therefore, its revocation is also so regarded. It is subject to tabling and disallowance in the Parliament under sections 38 and 42 of the LIA.
Consultation under section 17 of the LIA has not been undertaken in this case. The instrument relates specifically to a named operator to end a particular trial.
The instrument commences on the day after it is registered and the approval and specification for obstacle clearance stops having effect at the end of 31 December 2008.
The instrument has been issued by the Deputy Chief Executive and Chief Operating Officer, a delegate of CASA, under subregulation 7 (1) of CAR 1988.
[Instrument number CASA 581/05]