22. Longitudinal Separation Flashcards
How do we apply longitudinal separation?
Spacing between the estimated positions of the
aircraft being separated is never less than a
prescribed minimum.
Separation between aircraft following the same or
diverging tracks may be maintained by application of
speed control, including the Mach number technique.
How do we achieve longitudinal Separation? (3)
–Depart at a specified time
–To lose time to arrive over a geographical location at a specified time
–To hold over a geographical location until a specified time
How do we achieve separation if AC are departing at a specified time?
One-minute separation - Tracks diverging by at least 45 degrees immediately after take-off.
Two minutes separation - preceding aircraft is 40kt or more faster than the following aircraft and both aircraft will follow the same track.
Five-minute separation - while vertical separation does not exist if a departing aircraft will be flown through the level of a preceding departing aircraft and both aircraft propose to follow the same track.
Application of longitudinal separation (3)
Same Track
Reciprocal Tracks (Opposite direction)
Crossing Tracks
What is Same Track?
When the track of one aircraft is separated from
the track of the other by less than 45°
What is Reciprocal Track?
When the track of one aircraft is separated from
the reciprocal of the other by less than 45°
What is a Crossing Track?
Intersecting tracks which are not classed as
‘same’ or ‘reciprocal’
En-route Separation
Time Based
Same Level & Track
Minimum - 15 minutes
Reduced to 10 Minutes - if navigation aids permit frequent determination of position and speed.
Reduced to 5 minutes - Provided the preceding aircraft is maintaining a TAS 20kts or more faster than the succeeding aircraft, that have reported over the same exact reporting point or departed from the same Aerodrome.
En-route Separation
Aerodrome Departure vs En-route Aircraft
After the en-route aircraft has reported over a
fix, so located as to ensure that 5 minute
separation can be established at the point the
departing aircraft will join the route.
Reduced to 3 minutes
provided the preceding aircraft is maintaining a
TAS of 40kts or more faster
En-route Separation
Time Based
Crossing Tracks - Same Level
Aircraft at same cruising level
15 mins - Standard
10 minutes - As navigation aids permit frequent determination of position and speed. (In Europe)
En-route Separation
Time Based
Same Tracks
No Vertical Separation
Minimum - 15 minutes (Standard)
10 minutes - Navigation aids permit frequent determination of position and speed. (Good navigation aids)
5 minutes - Provided that the level change is commenced within 10 minutes of the time the second aircraft has reported over an exact reporting point (Speed)
En-route Separation
Distance Based
Same Track/Same Level
Minimum - 20nm (37km)
Reduced to 10nm (19km) Provided:
The leading aircraft maintains a TAS of 20kts (37km h) or more faster than the succeeding aircraft.
Provided each aircraft utilises
- “on-track” DME stations or
- on-track DME and collocated waypoint if one using GNSS or
- same waypoint if both using GNSS.
En-route Separation
Distance Based
Crossing Track / Same Level
Same as “Same Track” Minima
Minimum - 20nm (37km)
Reduced to 10nm (19km) Provided:
The leading aircraft maintains a TAS of 20kts (37km h) or more faster than the succeeding aircraft.
Provided each aircraft utilises
- “on-track” DME stations or
- on-track DME and collocated waypoint if one using GNSS or
- same waypoint if both using GNSS.
En-route Separation
Distance Based
Climbing/Decending
Same Track
10nm
while vertical separation does not exist;
Provided each aircraft utilises
- “on-track” DME stations or
- on-track DME and collocated waypoint if one using GNSS or
- same waypoint if both using GNSS.
AND
- One aircraft maintains a level while vertical separation does not exist;
- Separation established by obtaining simultaneous DME and/or GNSS readings from the aircraft.
DISTANCE BASED – RECIPROCAL TRACK
10 MILES If both aircraft are using “on-track”
DME and/or collocated/same waypoint;
One aircraft may be cleared to climb or descend
to or through levels occupied by the other
aircraft provided:
It has been positively established that the
aircraft have passed each other and at least
10nm apart (or other such value as
prescribed by the appropriate ATS authority)
Longitudinal separation minima with Mach
number technique based on time
10 minutes or
Opposite direction traffic
Slide 31?
Where lateral separation is not provided, vertical
separation shall be provided
for at least 10 minutes prior to and after
the time the aircraft are estimated to pass, or the
time the aircraft are estimated to have passed.
Provided that it has been determined that the aircraft
have passed each other, this minimum need not apply
