8-7-3. LONGITUDINAL SEPARATION
In accordance with Chapter 8, Offshore/Oceanic Procedures, Section 3, Longitudinal Separation, apply the following:
10 minutes provided that:
(a) both aircraft are in level flight at the same Mach number or the aircraft are of the same type and are
both operating in cruise climb, and one of the following;
- (1) The aircraft concerned have reported over a common point; or,
(2) If the aircraft have not reported over a common point, the appropriate time interval being applied
between aircraft exists and will exist at the common point; or,
(3) If a common point does not exist, the appropriate time interval being applied between aircraft
exists and will exist at significant points along each track.
- 15 minutes between aircraft in supersonic flight not covered in subparagraph a1 above.
Turbojet operations (subsonic flight):
- Apply the prescribed minima in accordance with para 8-3-3, Mach Number Technique; or
Where tracks diverge from the common point and the following aircraft is maintaining a greater Mach Number
than the preceding aircraft:
- (a) At least 10 minutes longitudinal separation exists at the point where the tracks diverge; and
(b) At least 5 minutes longitudinal separation will exist where minimum lateral separation is achieved
(whichever is estimated to occur first);
(1) At or before the next significant point (normally within ten degrees of longitude along track(s)),
- (2) Within 90 minutes of the time the following aircraft passes the common point, or
- (3) Within 600 NM of the common point. 3. Apply 15 minutes between all other turbojet aircraft.
- Apply 20 minutes between aircraft operating in the West Atlantic Route System (WATRS), or
- Apply 30 minutes between aircraft operating outside of the WATRS.
NOTE: The WATRS area is defined as beginning at a point 27°00'N/77°00'W direct to
20°00'N/67°00'W direct to 18°00'N/62°00'W direct to 18°00'N/60°00'W direct to
38°30'N/60°00'W direct to 38°30'N/69°15'W, thence counterclockwise along the New York Oceanic
CTA/FIR boundary to the Miami Oceanic CTA/FIR boundary, thence southbound along the Miami Oceanic CTA/FIR
boundary to the point of beginning.
Clear an aircraft for an ADS-B In Trail Procedure (ITP) climb or descent provided the following conditions are
- The ITP climb or descent has been requested by the pilot;
The aircraft identification of each reference aircraft in the ITP request exactly matches the Item 7 -
aircraft identification of the corresponding aircraft's filed flight plan;
- The reported ITP distance between the ITP aircraft and any reference aircraft is 15 NM or more;
Both the ITP aircraft and reference aircraft are either on:
- (a) same identical tracks and any turn at a waypoint shall be limited to less than 45 degrees; or
- (b) same tracks with no turns permitted that reduce required separation during the ITP.
NOTE: Same identical tracks are where the angular difference is zero degrees.
No speed or route change clearance shall be issued to the ITP aircraft until the ITP climb or descent is
- The altitude difference between the ITP aircraft and any reference aircraft shall be 2000 ft or less;
No instruction to amend speed, altitude or route shall be issued to any reference aircraft until the ITP climb
or descent is completed;
- The maximum closing speed between the ITP aircraft and each reference aircraft shall be Mach 0.06; and
- The ITP aircraft shall not be a reference aircraft in another ITP clearance.
NOTE: ATOP is designed to check for the above criteria prior to allowing the minima to be provided.
Minima based on distance using Automatic Dependent Surveillance - Contract (ADS-C):
Apply the minima as specified in TBL 8-7-1 between aircraft on the same track within airspace designated for
Required Navigation Performance (RNP), provided:
(a) Direct controller/pilot communication via voice or Controller Pilot Data Link Communications (CPDLC)
is established, and
(b) The required ADS-C periodic reports are maintained and monitored by an automated flight data processor
(for example, ATOP).
TBL 8-7-1 ADS-C Criteria
||RCP See Note 1
||RSP See Note 2
||Maximum ADS-C Periodic Reporting Interval
- 1. Required Communication Performance (RCP).
- 2. Required Surveillance Performance (RSP).
Aircraft on reciprocal tracks may be cleared to climb or descend to or through the altitude(s) occupied by
another aircraft provided:
(a) An ADS-C position report on at least one of the aircraft has been received beyond the passing point,
- (b) The aircraft have passed each other by the applicable separation minimum.
NOTE: ATOP has been designed to check for the above criteria prior to allowing the minima to be provided.
When an ADS-C periodic or waypoint change event report is overdue by 3 minutes, the controller must take
action to obtain an ADS-C report.
If no report is received within 6 minutes of the time the original report was due, the controller must take
action to apply another form of separation.
Aircraft on the same track may be cleared to climb or descend through the level of another aircraft provided:
(a) The longitudinal distance between the aircraft is determined from near simultaneous ADS C demand
reports and the ATOP software is used to ensure the following conditions are met;
(b) The longitudinal distance between the aircraft, as determined in (a) above, is not less than:
(1) 15 NM when the preceding aircraft is at the same speed or faster than the following aircraft; or
(2) 25 NM when the following aircraft is not more than Mach 0.02 faster than the preceding aircraft
- (c) The altitude difference between aircraft is not more than 2000 ft;
- (d) The clearance is for a climb or descent of 4000 ft or less;
- (e) Both aircraft are filed as single flights not flying in formation with other aircraft;
- (f) Both aircraft are in level flight at a single altitude;
- (g) Both aircraft are same direction;
- (h) Neither aircraft are on a weather deviation;
- (i) Neither aircraft have an open CPDLC request for a weather deviation;
- (j) Neither aircraft are on an offset with a rejoin clearance; and
(k) The clearance is issued with a restriction that ensures vertical separation is re established within
15 minutes from the first demand report request.