Departure traffic management[PDF]
- 1 Introduction
- 2 Departure management
- 3 Separation minima during departure
- 4 Use of Radar
- 5 See also
- 6 Reference
- 7 Author
Their main tasks are the management of the approach aircraft from the last en-route point to the final approach path and the management of the departure aircraft from the initial climb after take-off to the en-route phase crossing their area.
In IVAO, the APP controller shall handle both arrival and departure when he is connected alone with no DEP controller. In some large airports where a departure frequency is published, a DEP controller can open the position in order to take charge of all departures. This will let the APP handle all the arrivals and transit aircraft.
For the majority of large airports, Standard Instrument Departure procedures (SID) for IFR flights are available and published on departure charts.
For some smaller airports, pilots will fly generally published an omnidirectional departure or an omnidirectional departure issued by air traffic controllers.
The departure procedures to be followed by any IFR aircraft shall be provided in the IFR clearances given by the controller who is in charge of the ground or delivery position.
The SID departure given by the controller to the aircraft should normally follow its flight plan. Sometimes, the SID can be different due to the specific airfield rules or the traffic congestion. The DEP controller is responsible to deliver the instruction(s) to permit the departing aircraft to join his first en-route fix.
The DEP controller should know the exact omnidirectional clearance given in order to perform his task.
- After take-off, direct turn towards the first en-route point
- After take-off and passing a cleared altitude (or FL), direct turn towards the first en-route point
- After take-off, initial turn and after passing a cleared altitude (or FL), direct route towards the first en-route point
- After take-off, direct route towards a radio navigation beacon
- Minimum climb rate in ft/min or %
- Interception of a VOR radial or NDB track
- Fly a DME arc
- Fly a track until a given DME distance
Controller tasks during departures
Before reaching their cruise altitude, aircraft will perform a climb phase until reaching their first assigned flight level.
- It is usual (even in real life) to grant direct routes to departing flights in order to shorten their route and also provide separation.
- It can be possible for the controller to route the aircraft away from the published track in order to fulfil this separation and/or climbing goal by using radar vectoring or by issuing direct to fix clearances.
Climb phase management
- Assign a higher speed and/or a lower climb rate
- Assign a lower speed and/or a higher climb rate
- Ask the pilot to maintain a given climb rate (minimum or maximum)
- Ask the pilot to maintain a given flight level (to undercross arrivals)
- Ask for a speed (IAS) decrease or increase
To avoid potential conflicts and optimize departure trajectories the DEP controller may also assign headings (also to avoid maintaining an aircraft at a low flight level when the pilot wishes to climb to the cruise level):
- Grant direct routes
- Provide radar vectoring
Separation minima during departure
- Ensure safety for each aircraft with respect to aircraft performance and minimum separation between all aircraft at any time (whether they are totally or partially under his control)
- Not give any altitude clearance below minimum safety altitudes i.e. MRVA for Minimum Radar Vectoring Altitude or MSA Minimum Sector Altitude where they are applicable to prevent any potential terrain collision
- Prevent any potential terrain collision
Separation definition and concerned traffic
As established by ICAO regulation, traffic separation must be provided:
- for all flights in class A and B airspaces
- for IFR and SVFR from each other and from VFR in class C airspace
- for all IFR and SVFR from other IFR/SVFR in class D and E airspaces
The separation conditions applied to night VFR (NVFR) depend on the country. NVFR might be treated as SVFR or normal VFR depending on the local regulations.
Radar separation minima for IFR
- 1000ft over the whole approach and departure procedure
- 3NM when reduced approach separation is applicable to the TMA area.
Wake turbulence category impact on separation
|Succeeding Aircraft||behind||preceding aircraft||Separation minima|
Loss of separation
Example of clearance presenting a potential risk of separation loss (=ATC fault): 2 aircraft cleared to the same point with the same climb clearance with approximately the same estimated time.
Management by flight level steps
When two or more aircraft should potentially cross the same flight level with a horizontal regulation separation smaller than 8 NM within a controlled airspace with radar assistance, the ATC shall stop the lower aircraft climbing and provide a least the minimum vertical separation between those aircraft until the horizontal separation is above the requested regulation separation of 8NM or minimum separation.
Management by heading modification
Management using offset parallel route
Let’s consider the case of a climbing aircraft having another aircraft in front of him on the same trajectory, at a higher level and at much lower speed. A possible method is the use of offset parallel route.
This method offers several advantages:
- It allows aircraft to overtake another by following the same route sharing the same flight level whilst ensuring the needs of lateral separation
- It allows aircraft to overtake another when climbing or descending through a conflicting flight level with another levelled aircraft whilst ensuring the needs of lateral separation
The disadvantage of this method is the pilot capacity to perform this type of operation. The pilot shall have a flight management computer with this function implemented and RNAV capacity.
Use of Radar
Typical distance between vectored aircraft depends on the runway capabilities, the navigation equipment used during the procedure, the weather and/or the airport configuration.
Why the use of radar vectoring
Radar vectoring can be used by the ATC as a complementary tool in order to enhance:
- The optimisation of departing aircraft climb inside or outside an arrival flow
- The climbing regulation in complex situations when classical management is failing
- The assistance to pilots in emergency or pan
- The assistance to lost pilots or deviating pilots from their cleared track
- Other cases where the situation needs it like specific pilot request, pilot off-track…
- The aircraft safety: vectoring near mountainous areas or high landmarks where vertical obstacle clearance should be infringed, descent clearance with ground proximity warning, vectoring in areas below MRVA or MVA outside the published approach path
- The aircraft separation: vectoring with an immediate or future effect of a reduction of separation between traffic under minima. He must ensure that a suitable separation is kept every time after he issues a clearance.
Where radar vectoring can be used?
- Regulation of your country/division cannot permit it on your airfield or all airfields
- Due to the proximity of mountainous, prohibited, restricted (military) areas, radar vectoring can be restricted or forbidden
- Approach paths are below minimum radar vectoring altitudes (MVA or MRVA) in the considered sector if they are published
- Approach and arrival paths are below minimum sector altitude (MSA) where minimum radar vectoring altitudes are not published on charts. (IVAO)
- VID 150259 - Creation
- VID 200696 - Update
- VID 531824 - Wiki Integration
DATE OF SUBMISSION
- 03:32, 14 May 2021
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