Document ID: chunk:federal_register_of_legislation:F2023C00696:body:0:p47
Version: federal_register_of_legislation:F2023C00696
Segment Type: other
Provision Reference: 
Character Range: 168526–182662

GPSRNAV; or
                                                                                                                                                                                                                                                                                                                                                                                                                                                                             (ii) GPSOCEANIC.
    Note 1   In 4a, 4b and 4c, if the distance obtained is close to the minimum, then consideration must be given to a descending aircraft being faster than the cruising aircraft, or a climbing aircraft being slower than the cruising aircraft. ATC may impose speed restrictions or requirements to ensure the required separation is maintained.
    Note 2   In 4b and 4c, if the position of 1 aircraft is determined by radar or ADS-B, the applicable ATS surveillance system minimum must be added.
D4d                                                                                                                                                                                                                                                                                                                                                     Leading aircraft descending through level of following climbing aircraft                                             1. The leading aircraft A is descending through the level of C (climbing).
15 NM                                                                                                                                                                                                                                                                                                                                                                                                                                                                        2. DME distances must be checked in sufficient time to ensure vertical separation is maintained if insufficient distance exists to apply this standard.
                                                                                                                                                                                                                                                                                                                                                                                                                                                                             3. Distance information must be derived from:
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                (a) DME; or
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                (b) in CTA only:
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  (i) GPSRNAV; or
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  (ii) GPSOCEANIC.
                                                                                                                                                                                                                                                                                                                                                                                                                                                                             4. When using DME-derived information for level changes above FL 290, both aircraft must be on the same side of the DME beacon.
D4e                                                                                                                                                                                                                                                                                                                                                     Inbound aircraft to a controlled aerodrome                                                                           1. Both A and B are inbound aircraft and the leading aircraft A is within 30 NM of a controlled aerodrome with DME.
15 NM                                                                                                                                                                                                                                                                                                                                                                                                                                                                        2. The aircraft are assigned levels which are vertically separated.
Arriving Aircraft                                                                                                                                                                                                                                                                                                                                                                                                                                                            3. Distance information must be derived from:
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                (a) DME; or
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                (b) in CTA only:
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  (i) GPSRNAV; or
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  (ii) GPSOCEANIC.
D5                                                                                                                                                                                                                                                                                                                                                      Change of level                                                                                                      1. Both A and B are inbound aircraft and the leading aircraft A is within 20 NM of a controlled aerodrome with DME.
10 NM                                                                                                                                                                                                                                                                                                                                                                                                                                                                        2. The aircraft are assigned levels which are vertically separated.
Arriving Aircraft                                                                                                                                                                                                                                                                                                                                                                                                                                                            3. Both aircraft are DME equipped.
D6                                                                                                                                                                                                                                                                                                                                                      Change of level                                                                                                      1. Both A and B are inbound aircraft and the leading aircraft A is within 15 NM of a controlled aerodrome with DME.
5 NM                                                                                                                                                                                                                                                                                                                                                                                                                                                                         2. The aircraft are assigned levels which are vertically separated.
Arriving Aircraft                                                                                                                                                                                                                                                                                                                                                                                                                                                            3. Both aircraft are DME equipped.
                                                                                                                                                                                                                                                                                                                                                                                                                                                                             4. Wake turbulence standards are applied.
D7                                                                                                                                                                                                                                                                                                                                                      Change of level                                                                                                      1. One aircraft maintains level while vertical separation does not exist.
A DME distance proportional to the rate of closure (IAS) as deter-mined from the following DME separation tables for aircraft rate and amount of level change                                                                                                                                                                                           Also applicable if a non-DME equipped aircraft is on the safe side of the aid at the commencement of level change    2. DME distances are checked when the aircraft are vertically separated by the minimum amount appropriate to the DME table to be used.
                                                                                                                                                                                                                                                                                                                                                                                                                                                                             3. The level change is commenced within 1 min of obtaining DME distances. When the separation is on the minimum, instructions must be issued to ensure