11.1.1.1 Changes to ATIS wind information must be provided to pilots with a take-off or landing clearance if it is considered that it would be of significance to the aircraft operation.
11.1.1.2 The ATIS code ‘ZULU’ must be retained exclusively in all locations for use only with ATIS broadcasts relating to out of hours operations or when a control zone is de-activated.
11.1.1.3 ATIS ZULU:
(a) must include the following:
(i) the expected re-opening time of the Tower;
(ii) CTAF and PAL frequency;
(iii) the preferred runway or circuit direction;
(iv) noise abatement procedures;
(v) works in progress; and
(b) may include operational information of an unchanging nature which provides immediately useful information to pilots.
11.1.2 Safety Alerts
11.1.2.1 A safety alert must be issued to an aircraft when a controller is aware the aircraft is in a situation which is considered to place it in unsafe proximity to terrain, obstructions, or other aircraft.
11.1.2.2 Once the pilot advises that action is being taken to resolve the situation, the issuance of further alerts may be discontinued.
11.1.3 Altimetry
11.1.3.1 Information concerning Transition Altitude and Transition Layer can be found in AIP ENR 1.7.
11.1.3.2 The differences between Area QNH for adjacent zones and terminal areas must not exceed 5 hectopascals. On the occasions that ATS observe a difference greater than 5 hectopascals between the terminal QNH and the forecast Area QNH, ATS must notify the appropriate meteorological office immediately.
11.1.4 Traffic Information
11.1.4.1 In providing ATS surveillance services within controlled airspace, including Class E airspace, or designated restricted airspace, ATC has no responsibility to initiate avoiding action in respect of unknown aircraft which can reasonably be assumed to be outside controlled airspace.
11.1.4.2 ATC must advise aircraft leaving controlled airspace of observed traffic within the airspace to be entered where:
(a) the pressure altitude derived level information of observed traffic indicates it is operating within 2000 FT of the base of CTA; or
(b) in the opinion of the controller other information indicates a potential conflict exists.
11.1.4.3 In Class G airspace, IFR and MLJ aircraft must be provided with traffic information on other conflicting IFR and MLJ aircraft.
Section (a) maintaining VFR-on-top; or - Manual of Standards Part 172—Air Traffic Services - (a) maintaining VFR-on-top; or | Zoe
11.1.4.4 In Class E airspace, flights:
(a) maintaining VFR-on-top; or
(b) operating VFR climb/descent; or
(c) using IFR Pick-up;
must be provided with:
(d) mutual traffic information:
(i) on each other; and
(ii) on IFR and MLJ flights; and
(e) traffic information on VFR flights as far as practicable.
Note Provision of traffic information is based on flight category, and not on the chosen procedure at the time of the request.
11.1.4.5 If the pilot in command of an IFR or MLJ aircraft at a non-towered aerodrome reports to the unit providing an ATS for the aerodrome that his or her aircraft is taxiing at or airborne from, the aerodrome, the unit must inform the pilot of conflicting traffic which is not on the CTAF.
11.1.4.6 The unit providing an ATS for a non-towered aerodrome must inform IFR or MLJ aircraft inbound to the aerodrome of conflicting traffic regardless of where the confliction will occur. However, this obligation ceases when the pilot reports “CHANGING CTAF” or that he or she is changing to the MULTICOM frequency.