Separation Standards - Distance

Question 1

D2 - 20nm DME/GNSS cruise

Answer 1

Distance information is provided by:
a) DME or;
b) GNSS in CTA only, by RNP2 or RNP4 approved aircraft

Question 2

For standards D1 to D4, what are the conditions for the use of GNSS

Answer 2

In CTA only, GNSS distance information may be provided by RNP2 and RNP4 approved aircraft for the application of standards D1 to D4 subject to the following conditions

a) where a mix of GNSS and DME distances are used, do not use distance reports if one aircraft is within 20NM of the reference point; and

b) when GNSS is used for both aircraft, you must apply the standard with reference to published waypoints

Question 3

D1

Answer 3

20NM climb to cruise

a) Distance information is provided by DME or GNSS in CTA only, by RNP2 or RNP4 approved aircraft

b) Where the following aircraft is climbing to lower levels or both aircraft are cruising to levels not vertically separated, both aircraft report reaching their cruising levels

c)if following aircraft reports at cruising level first, apply another form of separation immediately

Question 4

D4a

Answer 4

15NM

a) Distance information is provided by DME or GNSS in CTA only, by RNP2 or RNP4 approved aircraft

b) One aircraft maintains level while vertical separation does not exist and;

c)Above FL290, when a DME distance is provided, both aircraft must be on the same side of the DME beacon

Question 5

D3

Answer 5

20NM aircraft descending

a) Distance information is provided by DME; or

b) GNSS in CTA only, by RNP2 or RNP4 approved aircraft

Question 6

R3

Answer 6

30 NM

a) in CTA only and between
i) aircraft with approved SCNS;
ii) an aircraft with approved SCNS and an aircraft with a DME

b) Above FL290, when a DME distance is supplied by either aircraft, both are on the same side of the DME beacon

c) Both aircraft report reaching their cruising level

d) if the following aircraft reaches its cruising level first, take immediate action to ensure separation is maintained

e) Separation standards A3 and R3 may be transitioned across the CTA/OCA boundary provided that the conditions for both standards apply prior to transitioning

Question 7

R2

Answer 7

20NM - definite passing

a) In CTA only and between:

i) aircraft with approved SCNS
ii) an aircraft with approved SCNS and an aircraft with DME

b) Using the same waypoint, reports indicate that the aircraft have passed and the distance between them is opening; and

c) whenever a DME derived distance is 30NM or less, you apply a correction for slant range error

Question 9

D8a

Answer 9

10/12NM - Definite Pass

a)Distance information is provided by
i)DME; or
ii) GNSS, in CTA only, by RNP2 or RNP4 approved aircraft with reference to a published waypoint

b) do not mix GNSS and DME distances

c)Use on reciprocal tracks and tracks differing by more than 90 degrees

d) Reports indicate that the aircraft have passed and the distance is opening; and

e) Increase the standard to 12NM if DME distances are greater than 180NM

Question 10

D8b

Answer 10

5NM - definite passing

a) distance information is provided by:
i) DME or
ii) GNSS, in CTA only, by RNP2 or RNP4 approved aircraft with reference to a published waypoint

b) Do not mix GNSS and DME distances

c) Reports indicate that the aircraft have passed and the distance is opening; and

d) if using a DME distance, one aircraft is within 20NM of the DME beacon