7. RADAR SERVICES

Question 1

What types of service may be provided by military ATS units?

Answer 1

a. Radar Control.
b. Deconfliction Service (DS).
c. Traffic Service (TS).
d. Basic Service (BS).

Question 2

What is Radar Control?

Answer 2

Radar Control is an air traffic radar service in which pilots are given mandatory instructions to enable the prescribed separation minima between AS to be maintained. Such mandatory instructions will generally be associated with essential details of the conflicting traffic. No changes of heading or level are to be made without prior approval of the radar controller.

Note: In Class C airspace standard separation between AS operating under VFR need not be applied; pilots operating under VFR are to be passed traffic information on other VFR flights and should be given traffic avoidance advice if they request it.
RA3223

Question 3

What is DS?

Answer 3

DS is a surveillance based ATS where, in addition to the provisions of a BS, the controller provides specific surveillance derived traffic information and issues headings and/or levels aimed at achieving planned deconfliction minima, or for positioning and/or sequencing. However, the avoidance of other traffic is ultimately the pilot’s responsibility.

Question 4

To which aircraft shall controllers provide a DS and in which meteorological conditions?

Answer 4

a. A DS shall only be provided to flights under IFR outside CAS and in any metrological conditions.

Question 5

What will a controller expect a DS aircraft to do?

Answer 5

The controller will expect the pilot to accept headings and/or levels that may require flight in IMC. A pilot who is not suitably qualified to fly in IMC shall not request a DS unless compliance permits the flight to be continued in VMC.

Question 6

What are a controller’s responsibilities in terms of separation from uncoordinated traffic, when controlling a DS aircraft?

Answer 6

A controller shall provide traffic information, accompanied with a heading and/or level aimed at achieving the planned deconfliction minima. The deconfliction minima against uncoordinated traffic are:

(1) 5nm laterally (subject to surveillance capability and regulatory approval); or,
(2) 3000ft vertically and, unless SSR Mode 3A indicates that the Mode C data has been verified, the surveillance returns, however presented, should not merge.

Note: Mode C can be assumed to have been verified if it is associated with a deemed validated Mode A code. The Mode C data of AS transponding Mode 3/A code 0000 is not to be utilised in assessing deconfliction minima.

Question 7

Should a controller provide a DS aircraft with traffic information on deconflicted traffic?

Answer 7

A controller may, subject to workload, pass traffic information on deconflicted traffic in order to improve the pilot’s situational awareness.

Question 8

What are a controller’s responsibilities in terms of separation from coordinated traffic, when controlling a DS aircraft?

Answer 8

The deconfliction minima against AS that are under the control of the same controller, or that have been subject to co-ordination, are:

(1) 3nm laterally (subject to surveillance capability and regulatory approval); or,
(2) 1000ft vertically; (2000ft within active MDA/MTA above FL410, and above FL290 where both AS are not RVSM approved); or
(3) 500ft vertically (subject to regulatory approval).

Question 9

What might affect a controller’s ability to pass deconfliction advice?

Answer 9

High controller workload or RTF loading may reduce the ability of the controller to pass deconfliction advice and the timeliness of such information. Furthermore, unknown ASs may make unpredictable or high-energy manoeuvres. Consequently, it is recognised that controllers cannot guarantee to achieve these deconfliction minima; however, they shall apply all reasonable endeavours. The pilot shall inform the controller if he elects not to act on the controller’s deconfliction advice. The pilot then accepts responsibility for initiating any subsequent collision avoidance against that particular conflicting AS. However, the controller is not prevented from passing further information in relation to the conflicting traffic if in his opinion it continues to constitute a definite hazard.

Question 10

What rules apply to the provision of DS, in relation to the unit terrain safe level?

Answer 10

A DS shall only be provided to AS operating at or above the ATC unit’s terrain safe level, unless on departure from an aerodrome when climbing to the ATC unit’s terrain safe level, or when following notified instrument approach procedures. In all other circumstances, if a pilot requests descent below ATC unit terrain safe levels, controllers shall no longer provide a DS but should instead, subject to surveillance and RT coverage, apply a TS and inform the pilot. If a controller detects a confliction when an AS is below the ATC unit terrain safe level whilst departing from an aerodrome and climbing to the ATC unit terrain safe level, or when following notified instrument approach procedures, traffic information without deconfliction advice shall be passed. However, if the pilot requests deconfliction advice, or the controller considers that a definite risk of collision exists, the controller shall immediately offer such advice as follows:

(1) For AS on departure, controllers shall provide avoiding action advice and a terrain warning.
(2) For AS conducting pilot interpreted instrument approaches, controllers shall provide avoiding action advice and an associated terrain safe level to climb to or fly at. It is assumed that conformity with such advice will necessitate repositioning.
(3) For AS being provided with Ground Controlled and Surveillance Radar Approaches:
(i) If the terrain safe area for the procedure is known to the controller or indicated on the surveillance display, avoiding action may be passed without an associated climb instruction, as long as the controller ensures that the AS remains within the terrain safe area, and the turn instruction is such that the controller considers that the approach can be continued without the need for repositioning.
(ii) If the controller anticipates that the avoiding action turn will result in flight outside the terrain safe area or the approach not being able to be completed, a terrain safe level to fly at will also be provided, and repositioning will be necessary.

Note: When AS are in the initial stages of departure or on final approach, due to limited AS manoeuvrability, controllers need to balance the safety impact of passing deconfliction advice at these critical stages of flight against the risk of collision presented by conflicting AS. Consequently, deconfliction minima do not apply in these constrained circumstances and avoiding action is instead aimed at preventing collision. Furthermore, controllers need to be aware of the high flight deck workload that is likely to be present in the event of avoiding action which is at variance to the published missed approach procedure being followed. The procedures regarding deconfliction advice to AS on initial departure and final approach are designed to cater for ‘pop up’ conflictions over which the controller has no advance warning due to the uncontrolled nature of Class G airspace. Controllers should attempt to co-ordinate and deconflict observed traffic prior to allowing either the departure of an AS that is expected to require DS, or the final approach of an AS that is already receiving a DS. Where AS are transferred to the Aerodrome Controller once established on final instrument approach, ATC units should use internal ATC liaison processes to ensure that warnings of conflicting traffic are passed in a timely fashion to the pilot.

Question 11

What are the rules regarding the issue of headings to DS aircraft?

Answer 11

A pilot may operate under his own navigation or a controller may provide headings for the purpose of positioning, sequencing, navigational assistance, or to achieve deconfliction minima. If a heading is
unacceptable to the pilot he shall advise the controller immediately. Unless safety is likely to be compromised, a pilot shall not alter course without first obtaining approval from the controller, as the flight profile may have been co-ordinated against other airspace users without recourse to the pilot.

Question 12

What are the rules regarding the issue of levels to DS aircraft?

Answer 12

Controllers will normally provide level allocations for positioning, sequencing, navigational assistance, or to achieve deconfliction minima. If a level is unacceptable to the pilot, he shall advise the controller immediately. Unless safety is likely to be compromised, a pilot shall not change level without first obtaining approval from the controller, as an AS flight profile may be co-ordinated against other airspace users without recourse to the pilot.

Question 13

What is TS?

Answer 13

A TS is a surveillance based ATS, where in addition to the provisions of a BS, the controller provides specific surveillance derived traffic information to assist the pilot in avoiding other traffic. Controllers may provide headings and/or levels for the purposes of positioning and/or sequencing; however, the controller is not required to achieve deconfliction minima, and the avoidance of other traffic is ultimately the pilot’s responsibility.

Question 14

To which aircraft shall controllers provide a TS and in which meteorological conditions?

Answer 14

TS is available under IFR or VFR and in any meteorological conditions. If a controller issues a heading and/or level that would require flight in IMC, a pilot who is not suitably qualified to fly in IMC shall inform the controller and request alternative instructions.

Note: Pilots should be aware that a TS might not be appropriate for flight in IMC when other services are available.

Question 15

What are a controller’s responsibilities in terms of providing traffic information to TS aircraft and what might affect a controller’s ability to pass traffic information?

Answer 15

The controller shall pass traffic information on relevant traffic, and shall update the traffic information if it continues to constitute a definite hazard, or if requested by the pilot. However, high controller workload and RT loading may reduce the ability of the controller to pass traffic information, and the timeliness of such information.

Traffic is normally considered to be relevant when, in the judgement of the controller, the conflicting AS observed flight profile indicates that it will pass within 3nm and, where level information is available, 3000ft of the AS in receipt of the TS. However, controllers may also use their judgement to decide on occasions when such traffic is not relevant, e.g. passing behind or within the parameters but diverging. Controllers shall aim to pass information on relevant traffic before the conflicting AS is within 5nm, in order to give the pilot sufficient time to meet his collision avoidance responsibilities and to allow for an update in traffic information if considered necessary.

Question 16

What are the pilot’s responsibilities in terms of collision avoidance?

Answer 16

Whether traffic information has been passed or not, a pilot is expected to discharge his collision avoidance responsibility without assistance from the controller. If after receiving traffic information, a pilot requires deconfliction advice, an upgrade to DS shall be requested. The controller shall make all reasonable endeavours to accommodate this request as soon as practicable and provide deconfliction advice at the earliest opportunity.

Question 17

What should a controller consider when providing headings and levels to a TS aircraft?

Answer 17

When providing headings/levels for the purpose of positioning and/or sequencing or as navigational assistance, the controller should take into account traffic in the immediate vicinity, so that a risk of collision is not knowingly introduced by the instructions passed. However, the controller is not required to achieve defined deconfliction minima.

Question 18

What rules apply to the provision of TS, in relation to the unit terrain safe level?

Answer 18

Subject to ATS surveillance system coverage, TS may be provided below ATC unit terrain safe levels; however, pilots remain responsible for terrain clearance at all times. Other than when following a notified instrument flight procedure, a pilot requesting to descend below the ATC unit terrain safe level shall be reminded that he remains responsible for terrain clearance.

Question 19

What are the rules regarding the issue of headings to TS aircraft?

Answer 19

A pilot may operate under his own navigation or a controller may provide headings for the purpose of positioning, sequencing, or as navigational assistance. When operating under their own navigation, pilots may alter course as required; however, unless safety is likely to be compromised, pilots shall not change their general route or manoeuvring area without first advising and obtaining a response from the controller. When following an ATC heading, unless safety is likely to be compromised, a pilot shall not change heading without first advising and obtaining a response from the controller, as the AS may be co-ordinated against other airspace users without recourse to the pilot. If an ATC heading is unacceptable to the pilot he shall advise the controller immediately. Controllers shall only instigate heading allocations when the AS is at or above an ATC unit’s terrain safe level. However, if pilots request a heading from the controller whilst operating below the ATC unit terrain safe level, this may be provided as long as the controller reminds the pilot that he remains responsible for terrain clearance

Question 20

What are the rules regarding the issue of levels to TS aircraft?

Answer 20

Pilots may select their own operating levels or may be provided with level allocations by the controller for the positioning and/or sequencing of traffic or for navigational assistance. If a level is unacceptable to the pilot he shall advise the controller immediately. Unless safety is likely to be compromised, a pilot shall not change level or level band without first advising and obtaining a response from the controller, as the AS may be co-ordinated against other airspace users without recourse to the pilot. Levels allocated by controllers shall be terrain safe iaw the ATC unit’s terrain safe levels, unless an agreement is reached with the pilot, or such levels form part of VFR clearances for aerodrome arrival or to enter controlled airspace that by necessity require flight below the unit terrain safe levels; in such circumstances, the instruction shall be accompanied by a reminder that the pilot remains responsible for terrain clearance.

Notes: In order to reduce RT loading and increase flexibility, pilots who require to frequently change level whilst receiving a TS should request a ‘block’ Level/Altitude to operate within.

Question 21

What are the military exceptions for the provision of a TS?

Answer 21

The military specific exceptions for TS are as follows:

a. Controllers are authorised to provide vectors to a maximum of 500ft below the unit terrain safe level, in accordance with RA3232, without reference to responsibility for terrain clearance, when:
(1) An AS is performing a R-Vis recovery and is within 10nm of the aerodrome.
(2) An AS is performing a SPC or practise SPC, and is within 10nm, of the aerodrome.
b. Controllers should avoid vectoring AS towards higher areas of the RVC within 10nm of the Aerodrome if this would result in the AS being lower than 500ft below the RVC at any stage of flight.

Note: Under certain circumstances controllers operating at RN shore-based ATC units are exempt from the above provisions.

Question 22

What are the rules, for Terminal units, governing the provision of DS, or radar vectors under TS, to ASs transiting outside CAS?

Answer 22

Terminal controllers are to use the Radar Vector Chart (RVC) or Surveillance Minimum Altitude Charts (SMAC) to determine the lowest height, converted to altitude if necessary, below which a DS should not be provided, or vectors for ASs in receipt of a TS should not be instigated. Outside RVC/SMAC coverage, units are to use the relevant, agreed Area Radar Unit ASA. These are to be replicated in Unit Order Books and displayed in the ACR. Any changes to ASA will be promulgated by the relevant Area Radar Unit.

Question 23

What is a Procedural Service?

Answer 23

A A Procedural Service is an ATS where, in addition to the provisions of a Basic Service, the controller provides restrictions, instructions, and approach clearances, which if complied with, shall achieve deconfliction minima against other AS participating in the Procedural Service. Neither traffic information nor deconfliction advice can be passed with respect to unknown traffic.

Note: Procedural Service does not require information derived from an ATS surveillance system. Therefore, due to the ability for autonomous flight in Class G airspace, pilots in receipt of a Procedural Service should be aware of the high likelihood of encountering conflicting traffic without warnings being provided by ATC. Pilots flying in the vicinity of aerodromes, ATS routes, or navigational aids where it is known that a Procedural Service is provided, are strongly encouraged to attempt to establish RTF contact with the notified ATS provider.

Question 24

In what circumstances may a Procedural Service be provided?

Answer 24

CAP 774 states that a procedural service shall only be provided by controllers at ATC units with Regulatory Approval to provide such a service.

Question 25

What is the definition of a Basic Service?

Answer 25

A Basic Service (BS) is an ATS provided for the purpose of giving advice and information useful for the safe and efficient conduct of flights. This may include weather information, changes of serviceability of facilities, conditions at aerodromes, general airspace activity information, and any other information likely to affect safety. The avoidance of other traffic is solely the pilot’s responsibility.

Note: BS relies on the pilot avoiding other traffic, unaided by controllers/FISOs. It is essential that a pilot receiving this service remains alert to the fact that, unlike a TS and a DS, the provider of a BS is not required to monitor the flight.

Question 26

Under what circumstances may an AS be identified under a BS?

Answer 26

controller may identify an AS to facilitate co-ordination or to assist in the provision of generic navigational assistance, but is not required to inform the pilot that identification has taken place.

Note: Identification of an AS in receipt of a BS does not imply that an increased level of service is being provided or that any subsequent monitoring will take place. Controllers may allocate SSR codes to AS in receipt of a BS. The issuance of such a code does not constitute the provision of a surveillance ATS.

Question 27

What information should be passed to a pilot regarding the profile of a conflicting track when passing traffic information?

Answer 27

Whenever practicable, traffic information should be given in the following form:

a. Relative bearing in terms of the 12 hour clock with the optional prefix of “left or right” as appropriate; if the AS under service is established in a turn then cardinal points are to be used.
b. Distance from the conflicting traffic.
c. Relative movement of the conflicting traffic.
d. The level of AS, if known.
e. Speed of the conflicting traffic if considered relevant.
f. The type of AS if considered relevant.

Question 28

How should the relative movement of conflicting traffic be described?

Answer 28

Relative movement should be described by using one of the following terms as applicable:

a. Crossing – including the relative direction of movement “left to right” or “right to left” where there is relative movement; i.e. a change in the relative bearing between that of the conflicting traffic’s path and that of the AS under a service. Controllers should include the words “ahead” or “behind” where appropriate to assist the pilot in assessing the conflicting traffic’s flight path.
b. Converging – where there appears to be no change in relative bearing between the conflicting traffic’s flight path and the AS under a service and/or the controller perceives there to be a significant risk of collision.
c. Same Direction – where the conflicting traffic’s flight path is the same as that of the AS under a service.
d. Opposite direction – where the conflicting traffic’s flight path is approximately 180o opposed to that of the AS under a service but the flight paths are not converging.
e. Manoeuvring – where the conflicting traffic’s flight path and/or level information is unpredictable and/or showing significant variation.

Note: When passing traffic information the speed should be described by using the term “fast moving” or “slow moving” as appropriate.

Question 29

How should the level information of the conflicting traffic be described?

Answer 29

The level of conflicting traffic should be described by using the following terms as applicable:

a. “Indicating (flight) level (if known), 1000ft above/below” (climbing or descending maybe added if required).
b. “At (flight) level (if known)” (climbing or descending maybe added if required).

Question 30

List the approved methods of AS identification?

Answer 30

a. SSR Mode 3/A.
b. Turn Method.
c. Turn Method Using DF.
d. Position Report.
e. DF Fix.
f. Departing AS.

Question 31

Describe the Turn Method?

Answer 31

Ascertain the AS heading and, following a period of track observation, correlate the observed movement of a particular radar return with one or more heading changes of at least 30º as instructed, or by another controller, or as reported by the pilot. Where only approximate position information is available, a minimum of 2 turns of not less than 30º should to be used. During this procedure, a controller seeking to identify an AS should:

(1) Verify that the movements of not more than one radar return correspond with those of the AS.
(2) Exercise caution, particularly when employing this method in areas where changes of AS heading are commonly made as a navigational routine.
(3) Take account of the type and characteristics of the surveillance equipment, e.g. raw or processed radar, rate of scan, beam width, range scale of display, when deciding the amount of turn and the period of observation required to prove identification.
(4) Ensure that the manoeuvre(s) will not carry the radar return outside radar display coverage, through clutter, or into airspace where a specific clearance is required.

Question 32

Describe the Turn Method Using DF?

Answer 32

Observing a turn of not less than 30º together with relevant DF indications and a period of track observation. Range information derived from DME, TACAN or similar equipment should be used to assist identification when it is available.

Question 33

Describe the Position Report Method?

Answer 33

Period of track observation, associated with heading and position information, within known radar cover based on one or more of the following:

(1) Correlating a radar return with a position report from the pilot that the AS is:
(i) Over an exact reporting point which should be displayed on the radar map.
(ii) At a particular distance not exceeding 30nm on a particular radial from a collocated VOR/DME or TACAN. The source facility should be displayed on the radar map.
(iii) Over a notified visual reporting point or prominent geographical feature approved for the purpose and displayed on the radar map (the pilot is to be visual with surface and 3000ft or less above surface).

Question 34

Describe the DF Fix Method?

Answer 34

This method should be reinforced by an alternative method if there is any doubt about the identification because of:

(1) The close proximity of other radar returns.
(2) Inaccurate reporting from AS at high level or some distance from navigational facilities.

Question 35

Describe the Departing AS Method?

Answer 35

Observing radar response of a pre-notified departing AS. Identification should take place within one nm of the end of the runway in use unless otherwise authorised. Particular care should be taken to avoid confusion with AS over flying, carrying out a low approach, or departing from an adjacent runway or with AS holding overhead the aerodrome.

Question 36

What factors should be taken into account when turning an AS for identification?

Answer 36

a. Airspace restrictions.
b. Terrain in the AS reported, estimated or observed position.
c. Other radar returns (including permanent echoes, clutter, etc.).
d. Surveillance coverage.

Note: Where possible, turns should be used as initial positioning turns to save fuel and time.

Question 37

What can be assumed if a surveillance controller is unable to locate a free-calling AS?

Answer 37

If a surveillance controller is unable to locate a primary radar echo or SSR response which relates to the pilot’s reported position, one of the following may be assumed:

a. The AS is outside radar cover, in which case the pilot should be instructed to climb to a higher level, call later, or call another nominated radar agency.
b. The AS return is obscured by clutter or is presenting a poor aspect to the radar aerial. If available, an alternative radar may be selected, or the pilot should be instructed to change heading or call another nominated radar agency.
c. The pilot’s reported position is incorrect. A further position check should be requested and, if the situation is still unresolved, the pilot should be instructed to obtain a fix from the UK Emergency Fixer Service and to pass the notified position to the controller.

Question 38

When should Deconfliction Advice (DA) or Traffic information (TI) be reduced?

Answer 38

A controller should reduce DA or TI as follows:

(1) When the AS is operating close to the lateral or vertical limits of solid ATS surveillance system cover, or close to a radar overhead and there is potential for conflicting traffic to be detected late.
(2) When the AS is close to areas of permanent echoes or weather returns.
(3) When the AS is being flown in areas of high traffic density or the controller has a high workload (this may not be apparent on RT).
(4) When a controller suspects the performance of the ATC surveillance system equipment is degraded.
(5) Where primary radar is unavailable, and SSR alone is used to provide an ATS, non-transponding AS will not be detected. An SSR only service may be provided only if approved by the relevant authority.

Question 39

What actions should a controller take when reducing DA or TI?

Answer 39

Controllers should inform the pilot of reductions in traffic information along with the reason and the probable duration; however, it may not always be possible to provide these warnings in a timely fashion.

Question 40

When considering selection/deselection of processed channels on the Watchman radar what operational effects should controllers be aware of?

Answer 40

Normal Radar (NR) - Gives best target detection in clutter free areas. Provides tangential target detection.

Ground Clutter Filter (GCF) - Gives best target detection in areas of ground clutter.

Moving Clutter Filter (MCF) - Gives best target detection in areas of moving clutter (e.g. heavy rainfall)

Angels Suppression - Desensitises the radar to reduce Angels. Only fitted to a limited number of radar systems.

Radar Services should be reduced when any processing is inhibited (LED illuminated).

Question 41

What are the vertical limits of LARS, to whom is it available, and to what range from an airfield is the service provided?

Answer 41

a. In UK outside CAS, up to FL100.
b. To military and civilian ASs within the limits of radar/radio cover,
c. Service provided within approximately 30nm of each participating ATS unit.
d. The provision of LARS is at the discretion of the controller concerned, therefore occasionally the service may not be available.

Question 42

How is an Aerodrome Emergency Safe Altitude (ESA) calculated?

Answer 42

An ESA should be established within 100nm radius of a navigation facility. This altitude is based upon the highest obstacle in the 100nm area plus 1000ft, the sum rounded up to the next 100ft. In areas of mountainous terrain this obstacle clearance will be increased to 2000 ft.

Question 43

What is the procedure for descending an AS to low level?

Answer 43

a. When a pilot receiving a radar service requests descent to operate low level the controller should pass the QFE in hPa and clear the pilot to descend to a height that accords with the RVC, and instruct them to report approaching. Outside RVC coverage units are to use the relevant, agreed Area Radar Unit ASA. These are to be replicated in Unit Order Books and displayed in the ACR.
b. When the AS approaches the base of radar cover, or the pilot reports approaching his altitude/height cleared to, the controller is to pass the appropriate RPS if not already set, establish his intentions and either:
(1) Provide DS/TS.
(2) If requested by the pilot, provide TS/BS below the ASA or RVC after reminding the pilot that he is responsible for terrain clearance if providing a TS.
(3) Terminate service.

Question 44

When AS are in receipt of a radar service, who is responsible for terrain clearance?

Answer 44

When a pilot is receiving a radar service, responsibility for terrain clearance rests with:

a. The controller, if Radar Control is being provided.
b. The pilot, if a DS or TS is being provided.
c. The controller or the pilot, depending on the flight rules under which the flight of an AS in Class D and E airspace is conducted.

Question 45

What standard vertical separation is required outside CAS?

Answer 45

a. When the Mode C of conflicting AS has been verified - 3000ft.
b. Following co-ordination – 1000ft.
c. When the Mode C of the conflicting traffic has not been verified - 3000ft and the surveillance returns, however presented, should not merge.
d. Vertical separation using Mode C should not to be applied against conflicting traffic with Mode 3A code 0000.

Question 46

When may standard vertical separation be reduced in Terminal Radar?

Answer 46

Controllers should only apply reduced vertical separation of 500ft in accordance with the following requirements:

a. Both AS are in surveillance coverage and within the assured range of the surveillance system in use.
b. Both AS are in receipt of an ATS from the same controller or are the subject of military to military coordination.
c. Both AS are below FL100 and outside CAS other than Class D.

The application of reduced vertical separation to civil AS should be exceptional rather than routine and only at the agreement of the civil pilot.

Formations. Reduced vertical separation should not be applied when either speaking unit is a formation due to the fact that formation elements may be displaced by up to 100ft, except under conditions detailed in RA3228.

Question 47

When may standard lateral separation be reduced in Terminal radar?

Answer 47

Controllers should only apply reduced lateral separation of 3nm in accordance with the following requirements:

a. Both AS are in surveillance coverage and within the assured range of the surveillance system in use.
b. Both AS are in receipt of an ATS from the same controller or are the subject of coordination.
c. The surveillance system in use provides a data refresh rate of 5 seconds or better.
d. Both AS are outside CAS other than Class D and active TRAs.
e. When the AS is operating within Class E airspace and surveillance data is provided by NATS, and NATS has stipulated alternative separation minima.

Reduced Lateral Separation should not to be applied when providing SSR-Alone ATS.

Formations. Reduce lateral separation should not be applied when either speaking unit is a formation due to the fact that formation elements may be displaced by up to 1nm, except under conditions detailed in RA3228.

Question 48

What are the rules regarding separation standards for Radar to Visual recoveries and Radar Straight In Approaches?

Answer 48

Deconfliction minima should be applied until:

a. The point of confliction is in a MATZ, and;
b. The pilot of the AS conducting the radar to visual recovery is visual with an AS that is conducting an instrument approach, and;
c. Traffic information is passed to the pilot of the AS conducting the instrument approach, regarding the AS conducting the radar to visual approach.
d. If the AS on an instrument approach is a civil AS, the sequencing of radar to visual approaches against the civil AS should be exceptional rather than routine and the civil pilots’ agreement should be sought.
e. ASs conducting a straight in approach should also be subject to these conditions.

Question 49

What vertical separation is required using SSR Mode C, without co-ordination?

Answer 49

a. (1) When the Mode C of the conflicting AS has been verified:
(i) A minimum of 5000ft is to be maintained inside CAS.
(ii) A minimum of 3000ft is to be maintained outside CAS.
(2) When the Mode C of the conflicting AS has not been verified and both AS are outside CAS - 3000 ft and radar returns, however presented, should not merge.
(3) Vertical separation using Mode C should not to be applied against conflicting traffic with Mode 3/A code 0000.

Question 50

What vertical separation is required following co-ordination?

Answer 50

Following co-ordination the following vertical separation minima may be applied:

(1) Between subsonic AS:
(i) Up to FL290 1000 ft
(ii) FL290 – FL410 2000 ft (1000ft in RVSM airspace).
(iii) Above FL410 2000ft
(2) When one or both AS are supersonic:
(i) Up to FL450 2000 ft
(ii) Above FL450 4000 ft

Question 51

What are the rules for applying RVSM?

Answer 51

Area radar controllers can apply RVSM of 1000ft within the vertical and lateral limits of airspace notified as RVSM or RVSM transition airspace provided that:

a. Both AS are RVSM approved.
b. The radar display system shows the RVSM approval status of all AS involved to the respective controllers and the AS are subject to Standing Agreement Co-ordination Procedures; or co-ordination has been affected.

Note: Formation flights are considered as being non-RVSM approved, regardless of the approval status of the individual AS concerned. In order to ensure that RVSM is applied correctly, the RVSM approval status of the AS should be included in all forms of liaison phraseology (pre-notification, handover, cleared flight path requests and co-ordination). However, controllers may deem all British military FJ AS to be negative RVSM and are therefore not required to include the RVSM status of these AS when conducting verbal handovers or co-ordination with other military Area Radar units. This dispensation does not apply to UK based USAF FJ ASs

Question 52

What are the controller’s actions and responsibilities on being advised that a pilot is manoeuvring in accordance with an Airborne Collision Avoidance Systems Resolution Advisory?

Answer 52

1. When a pilot reports that he is manoeuvring as a result of receiving an ACAS Resolution Advisory, controllers should cease to provide instructions which would modify the ASs’ flight path until the pilot reports “Clear of Conflict”.
2. The controller should resume responsibility for providing separation for all AS affected by the Resolution Advisory when:
   a. The controller acknowledges a report from the pilot that the AS has resumed the current Air Traffic Control (ATC) clearance; or
   b. The controller acknowledges a report from the pilot that the AS is resuming the current ATC clearance and issues an alternative clearance which is acknowledged by the pilot.
3. Controllers should not routinely pass traffic information to AS conducting Resolution Advisory manoeuvres, or other AS affected by such
   manoeuvres.

Question 53

Under what circumstances would a controller consider passing traffic information to an AS manoeuvring in accordance with a ACAS RA?

Answer 53

There may be circumstances where the passing of traffic information is justified; consequently, controllers may provide traffic information under the following circumstances:

a. To AS conducting an Resolution Advisory manoeuvre if it is considered essential for flight safety (e.g., information on AS which are known to be in close proximity that are not transponding Mode C information).
b. To other AS affected by an Resolution Advisory manoeuvre if judged necessary by the controller (e.g., in airspace where the carriage and operation of ACAS and/or SSR transponders is not mandatory).

Question 54

What are the Class C deeming conventions?

Answer 54

When providing an ATS within Class C airspace (outwith active TRAs), controllers should deem separation to exist between:

a. AS under control and either known traffic whose SSR code is not that of a unit with approval to penetrate Class C; or
b. AS under control and unknown traffic.

AS under control at FL200, or FL250 above an active TRA, should be passed traffic information regarding conflicting unknown traffic; however, the radar contacts may be allowed to merge. This dispensation should not apply to AS within 5nm of the Class C boundary in respect of unknown traffic operating within MTAs and active TRAs.

Question 55

What is Traffic Information between ATS Personnel?

Answer 55

Traffic Information (TI) between ATS personnel, is information about an AS or its flight which is relevant to the provision of an ATS.

a. . The passing of TI does not imply a commitment to an agreed course of action and there is no undertaking to update the information that has been passed. The dynamic nature of an air traffic environment renders TI obsolete once passed. The passing or receiving of TI alone does not constitute co-ordination.
b. If, after receiving TI, a controller believes that co-ordination is necessary, he should use the term “Request co-ordination” and should follow the verbal procedure as per the RA3230.

c. When describing the height or altitude of an AS for the purposes of TI or agreeing coordination, controllers should also state the pressure datum on which
the AS is operating and the terms “Not Above”, “Not Below” or “Maintaining” as appropriate. Where the level of an AS is expressed as a Flight Level there is
no requirement to state the pressure datum.

Note: The RVSM approval status of the AS should be passed if it is operating in RVSM designated airspace.

Question 56

What is Traffic Co-ordination?

Answer 56

Coordination shall only be effected through negotiations between two or more parties who are vested with the authority to make executive decisions appropriate to the task being discharged. Coordination should only be agreed between qualified controllers. It should only be effected through an agreed course of action based on known information. Responsibility for obtaining and ensuring implementation of an agreed course of action should be vested in one of the parties involved.

Question 57

What are the approved forms of Traffic Co-ordination?

Answer 57

The following forms of traffic co-ordination are approved:

a. Tactical Co-ordination. Tactical Co-ordination is the temporary co-ordination of AS to which the co-ordinating controllers are providing, or are about to provide, an ATS. Tactical coordination should be achieved either verbally (face-to-face or over a landline) or silently using an electronic data communications system. The use of such system should be defined in Local/Unit Orders.
b. Tactical Co-ordination – AS Not Yet on Frequency. The releasing controller should ensure that the details of any co-ordination agreement are passed to the pilot in time for him to acknowledge compliance before changing frequency. This is particularly pertinent during an aerodrome departure where the pilot can change frequency shortly after take-off.
c. Tactical Co-ordination by Proxy. A controller can carry out co-ordination on behalf of another controller, provided that the procedure is defined and authorised in Local/Unit orders, and the traffic situation and time available allows the controller being represented to comply with the agreed course of action. Co-ordination of this nature is binding upon all parties involved in the agreement. Central or combined co-ordination positions serving more than one controller may be established at larger units.
d. Standing Agreement Co-ordination. Standing Agreement Co-ordination is co-ordination, which is implemented automatically, on a permanent basis, without communication between the controllers involved. It should only be effected iaw a written standing agreement between the units or sub-unit involved and should only be valid for the AS and circumstances specified in the agreement.

When describing the height or altitude of an AS for the purposes of traffic information or agreeing coordination, controllers should also state the pressure datum on which the AS is operating and the terms “Not Above”, “Not Below” or “Maintaining” as appropriate. Where the level of an AS is expressed as a Flight Level there is no requirement to state the pressure datum.

Question 58

For the purposes of Co-ordination, when is GAT considered to be on/off route?

Answer 58

a. On-route. When AS are flying along the alignment and within 5nm of the centreline of an upper ATS route (UAR) and other areas defined for the application of reduced co-ordination procedures.
b. Off-route. When AS are not considered to be complying with the conditions of On-route (ATS).

Question 59

What is meant by the term MARSA?

Answer 59

1. Military Accepts Responsibility for Separation of AS – within a formation of military AS the formation leader is responsible for separation between units comprising the formation.
2. When formations are joining up:
   a. VMC With the consent of the formation leader MARSA will apply once the other formation elements are established no less than 1000ft below the leader at which point the AS can be cleared to climb visually to join the formation.
   b. IMC With the consent of the formation leader MARSA will apply once the other formation elements are established 5nm horizontally and within 2000ft vertically. The final join up will be completed using internal aids under the direction of the formation leader.

Question 60

What are the procedures for military formation flights within CAS (Classes A-E)?

Answer 60

When flying within CAS (Classes A-D) and when under a radar service within Class E, the following procedures should be applied:

a. All military AS should fly within one nm laterally and longitudinally of each other at the same level. Where this not possible, formations will be split into elements separated by the prescribed ATC separation minima before entering CAS. Such elements may be either individual AS or smaller formations that can fly within one nm laterally and longitudinally and at the same level, each of which should be assigned a discrete SSR code with Mode C.
b. Prior to a formation entering CAS, controllers should obtain a confirmation on RT that all AS within elements are within one nm of each other and at the same level.
c. When a formation has been cleared to climb or descend in CAS controllers should obtain confirmation that all elements have reached the assigned level. If the vacation of a level is relevant for the purposes of co-ordination, controllers will obtain confirmation that all elements have vacated the level.
d. C130 station keeping equipment (SKE) formations may be exempted from the requirements of sub-paras a. and b. provided that:
(1) Lead and tail AS are squawking (with Mode C).
(2) The flight is operating in accordance with a relevant ACN.
(3) Prior to the formation entering CAS, the controller has obtained a confirmation on RT that all elements are at the assigned level.
e. With the exception of para d, formations that are subject to ACN action (e.g. Coronet Flights) or tactical negotiation between appropriate military supervisors and civilian watch managers use best practice (e.g. first and last ASs squawking), together with positive confirmation to ATC that all AS are established in the assigned level block.

Question 61

When can formations join and split in CAS (Classes A – E)?

Answer 61

Controllers will only permit a formation to join or split up in CAS under the following circumstances:

a. When an AS has an emergency and a formation join-up is essential.
b. Formations commencing a join-up prior to entering CAS are permitted to complete their join within CAS, when conditions allow, subject to maintaining standard separation from other ASs.
c. Within Class C airspace, controllers may allow formations to join up; however, they will give appropriate consideration to the formation’s proximity to UARs and other airspace users.
d. All elements involved in the formation join up should transpond Mode 3A plus C until established in formation.
e. Controllers can permit formation splits in CAS giving due regard to other airspace users and co-ordination requirements.

Question 62

How are Air Traffic Services provided to formations outside CAS?

Answer 62

A formation, with elements keeping station visually or by radar, of more than one nm length may receive an Air Traffic service outside CAS as follows:

a. The lead AS will squawk Mode 3A and Mode C. If the stream extends for 3nm or more, the last AS will also squawk. For longer streams, intermediate ASs will squawk as appropriate.
b. Flight Information service should be given to the lead AS only.
c. Controllers will identify the full extent of the stream formation during radar handovers, when effecting co-ordination and when passing TI to other controllers.

Question 63

What does the code word ‘EMBELLISH’ signify?

Answer 63

a. EMBELLISH is a codeword signifying that an AS is prepared to act as a target for fighter interception.
b. When under the control of an ATCRU, an EMBELLISH AS could be placed in a potentially hazardous situation if it is given avoiding action against conflicting traffic which, unbeknown to the controller, is a fighter carrying out interceptions under the control of a ACC/CRC. Therefore, when an ISTAR 1 (AEW) or ASACS unit selects an EMBELLISH AS for interception, details of the flight are required to be passed to the appropriate ATCRU. The ATCRU Supervisor will brief the relevant ATCRU controller of the intended interception and the controller will notify the AS and take this into account when passing information on conflicting traffic or initiating avoiding action. Notification of an immediate interception and identification of the fighter involved will be passed to the ATCRU by the Fighter Marshal.

Question 64

What are the conditions of Non-Deviating Status (NDS)?

Answer 64

a. The AUS is the central authority for authorising NDS flights and is the focal point for NDS applications, inter-unit negotiations and approvals.
b. AUS normally requires a minimum of 21 days notice of pre-flight requests for NDS in order to obtain agreement from the affected ATSUs or ASAC Units. Shorter notice applications may be considered on merit, but AUS may direct operating authorities direct to the appropriate ATSU(s) or ASAC unit(s) involved if the application cannot be processed in time by the AUS.
c. NDS affords priority of passage over all other OAT and GAT, except for ASs in emergency, Royal Flights, Air Defence Priority Flights, GAT with higher UK civil priority category or other higher priority Special flights.
d. Flights granted NDS will remain under radar control or procedural service. If in the interest of flight safety it should become necessary to give NDF flight avoiding action, such instructions from a controller are Mandatory.

Question 65

For controlling purposes, how are Research & Development flights categorised?

Answer 65

a. Cat A Flights. Cat A Flts are those R&D flights which are amenable to normal ATC procedures and could be controlled by an ATSU.
b. Cat B Flights. Cat B Flts are those R&D flights for which autonomous control by an R&D authority is not essential, but which require specific handling to allow them the freedom of operation necessary to achieve the objective of the flight.
c. Cat C Flights. Cat C Flts are those R&D flights for which autonomous control by an R&D authority is essential to either ensure the objectives of the flight are achieved or to meet the specific AS flight safety criteria.

Question 66

What are the rules governing radar handovers?

Answer 66

a. Satisfactory 2-way speech is possible on the landline.
b. Responsibility for the AS is transferred directly from controller to controller.
c. The AS is in an area of overlapping surveillance coverage.
d. The handover fulfils any standing agreement between the 2 agencies.
e. The releasing controller resolves any traffic conflictions before completing the handover.
f. Controllers should only conduct a handover in airspace in which they are authorised to provide an ATS.

Question 67

Where are military supersonic flights to be carried out within the UK FIR?

Answer 67

a. In the UK FIR Supersonic flights should be carried out under the following circumstances:
(1) Flights are to be made over the sea.
(2) AS heading directly out to sea may accelerate to supersonic speed when at least 10nm out to sea and along a flight line at least 20 degrees divergent from the mean line of the coast.
(3) Angle of dive is not to exceed the minimum necessary.
(4) Flights with the AS pointing towards land, turning or flying parallel to the coast should take place at least 35nm from the nearest coastline.
b. Supersonic flights at low level are to conform with the above, and providing a radar/visual search is maintained in order to avoid the following by the margins stated:
(1) Shipping and fixed or mobile oil and gas installations: 3nm.
(2) Civilian or military transport AS: 6nm.
(3) Helicopters, Helicopter main routes and corridors: 6nm.

Question 68

In what order should information to be given during a radar handover?

Answer 68

a. Console number or control position of the releasing controller.
b. Nature of task (e.g. VHF lower air transit) and callsign.
c. Position heading/track or vectoring instructions. (The releasing controller should pause at this point to allow the receiving controller to locate the radar return, say ‘contact’, and pass the new SSR code for assignment by the releasing controller).
d. FL/altitude and flight conditions (if relevant).
e. Type of AS.
f. Intentions (e.g. destination).
g. Any other relevant information, (e.g. type of service, RVSM approval status).

Note:

(1) The receiving controller will confirm receipt and understanding of the information by ‘reading back’; additionally, the receiving unit’s console number or control position will be passed to the releasing controller.
(2) The receiving controller will confirm (or change if required) the ATS with the pilot on initial contact.
(3) A shortened handover as defined in Command/Local Orders may be used in the case of pre-noted AS.

Question 69

What are the airspace features specific to the concept of Flexible Use of Airspace (FUA)?

Answer 69

a. Conditional Routes (CDRs). Non-permanent ATS routes.
b. Temporary Segregated Areas (TSAs). Reserved exclusively for specific ops to ensure the safety of all. These might include Danger and Restricted Areas or Military Training Areas.
c. Cross-Border Areas (CBAs). CBAs are TSAs established across national boundaries, where operations will be subject to procedures agreed by participating states.
d. Reduced Co-ordination Airspace (RCA). Specific portion of airspace within which GAT is permitted off-route without requiring controllers to initiate co-ordination against OAT. This procedure is applicable when OAT activity is minimal or non-existent.

Question 70

Under what circumstances should a controller transmit MA and CF procedures to a pilot?

Answer 70

a. To visiting AS in emergency, where appropriate including practice emergencies.
b. When requested by the pilot.
c. When the procedure is temporarily changed from that published.
d. When directed by the Operating Authority.

Note: During certain emergencies, e.g. flameout/fuel shortage, such procedures would be counter-productive and will be omitted.

Question 71

What is the ROCD restriction and why?

Answer 71

8000 feet per minute; in order to ensure the credible interaction of Airborne Collision Avoidance Systems and ground based safety nets.

Question 72

In what airspace does the ROCD apply?

Answer 72

When inside CAS within the London and Scottish FIRs/UIRs.

Question 73

What are the definitions of the following phraseology terms with regard to ROCD?

Answer 73

a. Climb/descend - Requires a pilot to climb/descend but at a rate not exceeding 8000fpm (unless in Class F & G).
b. Expedite - Requires a pilot to climb/descend at best rate but not exceeding 8000fpm (unless in Class F & G).
c. Expedite – no restriction - Requires a pilot to climb/descend at best rate without any restriction on ROCD (including in CAS).
d. No restriction - Informs a pilot that he may, at his own discretion climb/descend at best rate and without any restriction to his ROCD (including in CAS).
e. Climb/descent restricted at 8000fpm, acknowledge - Instructs a pilot to climb/descend at a rate not exceeding 8000fpm. Pilots must acknowledge the ROCD restriction. (All airspace classifications).

Question 74

In manoeuvring flights, what is the phraseology to be used by ATC to inform pilots that:

a. They can manoeuvre at rates in excess of the ROCD?
b. ROCD is re-imposed?

Answer 74

a. ‘C/S manoeuvre as required FL xxx – FL xxx no restriction, report one minute to completion’.
b. ‘C/S climb/descent restricted at 8000 fpm, acknowledge’.