Reference Aircraft One or two aircraft in the ITP volume but not at the desired flight level:
- With qualified ADS-B data
-
That meet the ITP criteria
-
That will be identified to ATC by the ITP Aircraft in the ITP clearance request.
Same Direction Refer toC.2.2 – Aircraft on the Same Direction.
C.2. PROCEDURE
C.2.1. ITP SEQUENCE
1. To initiate an ITP maneuver, the flight crew must check that the ITP criteria (refer to C.2.6 – ITP Criteria) are met. The ITP criteria ensure that the ITP Aircraft and the Reference Aircraft do not get closer than the ITP separation minimum (10 NM).
Figure C - 1: ITP separation minimum
2.
When the ITP criteria are met, the flight crew may request an ITP clearance. The ITP request contains the identification of the Reference Aircraft and the range to these aircraft. The ATC controller checks that conditions are met to maintain safe separations between ITP and Reference Aircraft.
3.
When these conditions are met, the ATC controller may deliver the clearance.
4.
When the ATC clearance is received, the flight crew must re-check that the ITP speed/distance criteria are still met before initiating the ITP maneuver.
C.2.2. AIRCRAFT ON THE SAME DIRECTION
The definition of the term Same Direction is derived from the term Same Track given in ICAO PANS-ATM, Doc 4444 (see References).
Aircraft are on a same direction when the difference of track angles is:
- Less than 45°, or
-More than 315°. Refer to Figure C - 2.
C.2.3. ITP VOLUME
The ITP criteria apply to aircraft that are in the ITP volume. The ITP volume is centered on the ITP Aircraft and defined as follows:
- Height: 4 000 ft above the aircraft in
Figure C - 2: Same direction
climb or below the aircraft in descent.
- Length: 160 NM. It is equal to procedural longitudinal separations (10 min or 80 NM) behind and ahead of the aircraft.
- Width: 40 NM. This width ensures that aircraft on parallel tracks are excluded of the ITP process (e.g. when lateral separations of 30 NM are applied).
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