Radar vectoring procedure and method[PDF]
- 1 Introduction
- 2 Condition of radar vectoring use
- 3 Vectoring general principles
- 3.1 Vectors phraseology during approach phase
- 3.2 Most common errors to avoid during vectoring
- 3.3 Radar vectoring for ensuring separation to prevent conflicts
- 3.4 Radar vectoring to reduce separation for optimal sequence
- 3.5 Radar vectoring for traffic management and sequencing
- 3.6 Radar vectoring example
- 4 Vectoring method on approach area for arrival aircraft
- 5 Vectoring and emergency
- 6 See also
- 7 Reference
- 8 Author
Air traffic control radars are devices which are used by air traffic controllers to detect, monitor and guide aircraft within a delimited airspace region.
Condition of radar vectoring use
In some airfield procedures, radar vectoring is a mandatory procedure to guide aircraft on the final approach track.
What is radar vectoring ?
Why using radar vectoring?
- the air traffic flow management in the arrival and/or approach phase of an instrument approach procedure.
- the IFR aircraft arrangement in sequence in the arrival and/or approach phase of an instrument approach procedure.
- the horizontal and vertical separation between all departing and/or approaching IFR aircraft
Radar vectoring can be used by the ATC as a complementary tool in order to enhance:
- The optimisation of departing IFR aircraft climb inside or outside an arrival flow
- The en-route IFR traffic regulation in complex situations when classical management is failing
- The assistance to IFR or VFR aircraft 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 requests.
- 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 a published approach path
- vectoring in areas below MSA outside a published approach path where no MRVA or MVA have been published
- The aircraft separation:
- vectoring with an immediate or future effect of a reduction of separation between traffic under minima.
- ensuring that a suitable separation is kept every time after ATC issues a clearance.
Where can radar vectoring be used ?
- Regulation of your country/division does not 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)
Vectoring general principles
- The aircraft safety by ensuring that radar separation minima are fulfilled at all times and for all airplanes, whether they are under his responsibility or not.
- Not to issue any altitude clearance below minimum vectoring altitudes (MRVA for Minimum Radar Vectoring Altitude) during radar vectoring (prevent any potential terrain collision) outside any procedure tracks
- Not to issue any altitude clearance below minimum safety altitudes (MSA for Minimum Safety Altitude) during radar vectoring (prevent any potential terrain collision) outside any procedure tracks
- Not to issue any altitude clearance below minimum procedural altitudes published ( Minimum altitude to respect on IAF)
Vectors phraseology during approach phase
- A heading (whenever the aircraft does not have a compatible heading already)
- An altitude (whenever the aircraft is not already established at final approach altitude)
- The final IFR approach clearance (only for interception of final approach track)
- A speed restriction instruction when requested
Here are some examples of standard phraseology:
- Basic vector instruction contains heading only:
KLM465, turn right heading 360
- Combined vector instruction with descent instruction:
KLM465, turn right heading 360, descent 2000ft
- Combined vector instruction with descent instruction and speed reduction:
KLM465, turn right heading 360, descent 2000ft, reduce 200 knots
- Combined vector instruction with final approach clearance:
KLM465, turn right heading 360, descent 2000ft, cleared ILS approach runway 03
Most common errors to avoid during vectoring
- Avoid providing radar vectors which make the aircraft follow exactly the published procedure
- Avoid issuing multiple (>4) heading clearances during vectoring(*)
- Avoid issuing multiple (>2) level flight steps during vectoring(*)
- Avoid issuing a published approach clearance after initiating the vectoring procedure, except for the final approach procedure or except for the approach procedure starting at the IAF where vectoring is not allowed after the IAF
- Avoid clearing a published approach procedure followed by radar vectors after a short period of time (typical <2min) (*)
- Avoid forgetting environmental constraints (noise abatement, terrain, vertical profile, etc…)(*)
- Avoid issuing vectoring instructions below minimum safety altitudes (MRVA: Minimum Radar Vectoring Altitude)
- Avoid issuing vectoring instructions outside your area of responsibility(*)
- Avoid issuing clearances which, as a consequence, lower the separation below the minima
* Except when facing any separation issues where the situation needs further clearances.
Radar vectoring for ensuring separation to prevent conflicts
Sometimes the situation in the approach area when managing several aircraft, the horizontal separation between two aircraft can be reduced to less than minimum separation distance.
In function of the configuration of airspace and traffic, the air traffic controller can give aircraft a minimum 45° turn up to 90°.
Radar vectoring to reduce separation for optimal sequence
Sometimes the traffic situation separation is greater than the requested regulation separation.
Radar vectoring for traffic management and sequencing
During approach, the distance between aircraft under radar vectoring depends on the runway capacity, the approach type (precision or non-precision) and category, the meteorological conditions (LVP) and the specific operational constraints of the airport.
- Always maintain 1000ft vertical separation between aircraft which present a risk of being closer than the minimum separation (in the short or the long term; this means that air traffic controllers should monitor all aircraft speed).
- The integration of an aircraft into the approach sequence shall be realized with maintaining aircraft 1000ft higher than the highest aircraft between its preceding and its following. The altitude shall be adjusted once the flight is correctly integrated and horizontally separated and regulated.
In the training phase when air traffic controller is learning the approach regulation using radar, one method is to gradually increase the value of horizontal separation minimum of one nautical mile for each additional aircraft and maintain the vertical separation of 1000ft between each aircraft. This procedure should ensure 5 miles of horizontal separations overhead FAF/FAP between all aircraft.
Radar vectoring example
The diagram below shows some examples of radar vectoring tracks from different situations:
The dotted arrows are possible tracks but not optimized and sometimes dangerous to use them in function of traffic:
- Blue dotted arrow track shows that the aircraft will overfly the final approach path. This track can be taken if the altitude is high enough to prevent any conflicts with final approach aircraft including the go-around aircraft.
- Red dotted arrow track shows that the aircraft will overfly the departure area where separation loss may occur with the departure aircraft and the go-around aircraft. This track can be used but the air traffic controller shall ensure the safety at all times.
Vectoring method on approach area for arrival aircraft
Vectors and phraseology on final approach
- An interception heading (whenever the aircraft does not have a compatible heading already)
- An interception altitude (whenever the aircraft is not already established at final approach altitude)
- The final IFR approach clearance
- A speed restriction instruction if requested
Example: KLM465, turn right heading 360, descent 2000ft, cleared ILS approach runway 03.
Approach gate on final approach track
- The angle between aircraft heading and approach axis shall be higher than 10° and lower than 45° and the best angle should be ideally 30° with respect to the approach axis
- The interception of the final approach axis shall take place from a point which guarantees a straight leg of at least 30 seconds (1NM or 2NM distance) ahead the point of the starting of the descent FAF or FAP.
- The interception of the descent slope is realized at level flight, once established on the final approach axis
- In case of an ILS approach, the interception of the glide slope shall be undercrossed at the published altitude (except when required or accepted by the pilot)
- Aircraft indicated airspeed shall be lower than 220kt IAS
Use of approach gate
Red point: Approach gate reference fix is defined by a straight leg of at least 30 seconds (1NM or 2NM distance) ahead the point where the aircraft start the descent (FAF or FAP point)
Black point: Final approach fix or point where the aircraft start the descent
Green zone: approach gate zone of good radar interception with a maximum of 45° angle
Black arrows: interception which respects the approach gate constraints
Red dotted arrows: interception which does not respect the approach gate constraints. These solutions should be used by ATC, only with pilot approval and where the situation demands it
Red arrows: bad interception. This situation forces the ATC to vector again the aircraft inside the approach gate zone
- A fix or the interception path of the initial or intermediate approach procedure where radar vectoring cannot be provided on final approach procedure
- The Initial Approach Fix (IAF)
Vectors shall be not used in areas where MRVA are higher than published procedures.
Runway axis may be not aligned with the final approach track
The configuration may be one of these:
- Offset localizer followed by visual approach (especially in mountainous areas)
- Offset non precision approach
- Non precision approach followed by visual approach
Vectoring on final track with a base leg
In order to ensure separation between aircraft on the final approach path and aircraft on the downwind track, the base leg created by radar vectoring shall be greater than the minimum IFR separation value considered in your approach area ( standard separation is 5NM and reduced separation is 3NM where applicable).
Vectoring using a 45°/180° procedural turn
Sometimes aircraft will arrive in a bad configuration which does not allow for immediate interception of the final approach track. One simple method is to use a 45°/180° procedural turn form for vectoring toward the approach gate area.
The procedural turn should be started beyond or at the approach gate reference point. The air traffic controller will:
- Give a new heading with a 45° turn (to the left or to the right) with respect to the approach axis
- Let aircraft maintain this heading for one minute minimum
- Give a half turn (180°) to the opposite direction of the runway (in order to make the aircraft compatible with the approach gate area).
- After half turn, give the final approach clearance
Vectoring and emergency
- Aircraft which are in sequence behind the aircraft in the emergency situation will continue through an unchanged route,
- Aircraft which are in sequence in front of the aircraft in the emergency situation will continue to the end of the approach sequence.
In the example above, the situation is:
- Approach sequence is constituted with 4 aircraft.
- The second aircraft in sequence is in emergency (red square)
The air traffic controller shall cancel the arrival of the first aircraft (orange square) and put it at the end of the approach sequence. The two other aircraft (green rectangle) shall continue and ATC shall monitor the emergency progress and the separation with other traffic.
- ICAO Documentation 4444 - Air Traffic Management - 16th Edition 2016 - Chapter 8.6.5
- VID 150259 - Creation
- VID 200696 - Update
- VID 531824 - Wiki Integration
DATE OF SUBMISSION
- 12:53, 14 May 2021
- This documentation is copyrighted as part of the intellectual property of the International Virtual Aviation Organisation.
- The content of this documentation is intended for aviation simulation only and must not be used for real aviation operations.