Document ID: chunk:federal_register_of_legislation:F2025C00187:reg:4:p6
Version: federal_register_of_legislation:F2025C00187
Segment Type: reg
Provision Reference: reg 4 (pt 6/6)
Character Range: 149797–151878

be used for checking the accuracy of a pressure altitude system.
       (3) Site elevation must be derived from aerodrome survey data that is:
(a) authorised in writing (as the case requires):
 (i) by CASA; or
 (ii) by an NAA; or
(b) supplied in writing by the relevant aerodrome operator.

CHAPTER 11 AIR TRAFFIC SERVICES — PRESCRIBED REQUIREMENTS

Division 11.1 Use of a class of airspace

11.01 Purpose and definition
       (1) For subregulation 91.255 (1), this Division prescribes requirements in relation to the use by an aircraft of a class of airspace or a portion of a class of airspace.
       (2) In this Division:
oceanic airspace means:
(a) for any airspace within an Australian FIR — the airspace within the lateral boundaries of an oceanic control area described in the AIP; or
(b) for any airspace not within an Australian FIR — the airspace:
           (i) described by the relevant NAA as an oceanic control area; or
           (ii) if subparagraph (i) does not apply — within an area, predominantly over an ocean or sea, where aircraft are unlikely to maintain VHF radiocommunications with an air traffic service.
Note   The effect of subsection (2) is that the vertical limits of an oceanic control area have no relevance to the definition of oceanic airspace within an Australian FIR. At the commencement of this instrument, the AIP document describing the geographic boundaries of oceanic control areas is the Designated Airspace Handbook.

11.02 Transition altitude, transition layer and transition level
       (1) This section applies to a flight using any class of airspace, whether controlled or uncontrolled, that is within an Australian FIR.
       (2) The transition altitude is 10 000 ft.
       (3) The transition level is as set out in Table 11.02 (3), so that for an area QNH mentioned in an item of column 1, the transition level is that mentioned in the same item of column 2.

     Table 11.02 (3) — Transition level

      Column 1                                    Column 2
Item  Area QNH                                    Transition level