ICAO separations Flashcards
When may an a/c be cleared to a level previously occupied by another?
When the other a/c has reported vacating the level except when;
Severe Turbulence is know to exist
The higher a/c is effecting a cruise climb; or
The difference in a/c performance is such that less than the applicable separation minimum may result
What is considered same track?
When the tracks of both a/c are separated by less than 45 degrees
What is considered reciprocal tracks?
When the track of one a/c is separated from the reciprocal track of another by less than 45 degrees
What are crossing tracks?
Any tracks not same or reciprocal
What is the standard time based long separation for a/c on same track and level?
15 mins or 10mins if nav aids permit frequenct determination of pos and speed
When may long sep for a/c at same level and on the same track be reduced and to what?
5 mins;
Where the first a/c is maintaining a TAS 20kts or more faster than the succeeding a/c that have reported over the same ERP of departed from the same aerodrome, or;
Between departing and en-route a/c after the en-route a/c has reported over a fix, so located as to ensure tha 5 minute sep can be established at the point the dep a/c will join the route and where the en-route a/c is 20kts or more TAS faster than the dep a/c
These can both be reduced to 3 mins where the speed of the first a/c is 40kts or more TAS faster than the succeeding a/c
What is the time based long sep for a/c crossing tracks?
15 mins or 10 mins where nav aids allow frequent determination of position and speed
What are the time based long seps for a/c on the same track but climbing/descending through levels?
15 minutes while vertical separation does not exist, 10 mins if nav aids allow frequent determination of position and speed
When may time based long sep between a/c on the same track but climbing/descending through levels be reduced?
To 5 mins while vertical sep does not exist provided that the level change is commenced within 10 mins of the time the second a/c has reported over an ERP
What are the time based long seps for a/c on reciprocal tracks where they are climbing/descending?
vertical sep will be provided for at least 10 minutes prior to and after the time the a/c are estimated to pass or the time the a/c are estimated to have passed. (not 20 mins total, just ensure that both a/c are 10 mins from the same point)
What does the term on track mean in regards to long sep between a/c using DME or GNSS?
That the a/c is flying either directly inbound or outbound from the station or waypoint
What is the distance based long sep for a/c on same track and level?
20nm provided both on track to DME station
When may distance based long sep be reduced and to what?
10nm provided that;
The leading a/c is 20kts or more TAS faster than the following a/c and each is on track to/from the DME station
What are the distance based long seps for a/c crossing tracks?
They are the same as the same-track ones provided the relative angle between tracks is less than 90 degrees
What are the distance based long seps for a/c on same track that are climbing/descending?
10nm while vertical sep does not exist provided they are on track to same DME station and one a/c maintains a level while vertical sep does not exist
What are the distance based long seps for a/c on reciprocal tracks?
10nm if both a/c on track to same DME and/or collocated waypoint, and provided that it has been positively established that the a/c have passed each other by at least 10nm
How is lateral sep obtained?
By requiring a/c to operate on;
Different routes, or;
In different geographical locations as determined by visual obs, use of nav aids or RNAV equip
What are the lateral seps for VOR in ICAO?
What are the lateral seps using NDB in ICAO?
What is the separation available between a/c that have already commenced the instrument procedure and departing a/c?
Up to three minutes before the estimated landing time of the arriving a/c. (expected landing time -3 mins is the clearance expiry time)
When may long and lat separations be reduced?
As determined by the appropriate ATS authority after prior consultation with the a/c operators
In accordance with regional air nav agreements after prior consultation with the a/c operators
in the vicinity of the aerodrome
