Section 7 - Air Traffic Control Services

Question 1

What is Radar Control?

Answer 1

ATS which pilots follow mandatory instructions to maintain prescribed separation.
Mandatory instructions will normally be associated with details of conflicting traffic.
Pilots will not change heading or level without approval of the controller.

Question 2

What is basic service?

Answer 2

BS is an ATS for the purpose of giving advice and information useful for he safe and efficient conduct of flight.
This may include weather info, changes of serviceability of facilities, conditions at aerodromes, general airspace activity and other information likely to affect safety.
The avoidance of traffic is solely the pilots responsibility.

Unlike TS and DS, the provider of a basic service is not required to monitor the flight.

Question 3

What conditions are required for the provision of a BS?

Answer 3

Controllers and FISO’s may provide a BS. Controllers may use surveillance equipment, FISO’s may not.
BS is available under IFR outside CAS in any met conditions, or under VFR.
A controller may ID for coordination or to provide Nav assistance, but is not required to inform the pilot.
ID/squawk allocation does not imply that a higher ATS is being provided.

Question 4

What are the rules regarding traffic information under a BS?

Answer 4

Pilots should not expect any form of traffic information. If a pilot requires traffic information, a TS should be requested.

Generic information on aerial activity in general terms may be passed to aid pilots SA. This info will not be updated unless it changes or the pilots requests an update.

A controller with access to surveillance information shall avoid the routine provision of TI.

If a risk of collision exists, the controller will issue a warning

Pilot remains responsible for collision avoidance without assistance

Deconfliction will not be provided. If a pilot requires deconfliction advice, a DS is to be requested. The controller will accommodate the request as soon as practicable.

Question 5

What are the rules regarding terrain for the provision on a BS?

Answer 5

BS is available at all levels and the pilot remains responsible for terrain clearance at all times.

Pilots will not be issued with terrain warnings.

Question 6

What are the rules regarding heading and level allocation under a BS?

Answer 6

Unless the pilot has agreed to maintain a specific course of action, the pilot may change heading or routing without informing the controller.
Other than for ID, a controller shall not issue headings, generic nav assistance may be provided.

Generic nav assistance may include information relative to the position of nav features. The controller may provide suggested track information and alternative routing suggestions.

Unless the pilot has entered into an agreement, the pilot may change level without informing the controller

Question 7

What is traffic service?

Answer 7

Surveillance based ATS, in addition to provisions of BS, controller will provide surveillance derived traffic info to assist pilots in avoiding other traffic.

Headings/levels may be provided for positioning/sequencing, but not required to achieve DS minima

Pilot remains responsible for collision avoidance

Question 8

What conditions are required for the provision of a TS?

Answer 8

Only by controller with access to surveillance system.

IFR outside CAS or VFR. Headings into
IMC: pilot shall inform controller if not qualified & request re-route. TS may not be appropriate for flight in IMC.

Controller shall ID, inform pilot & maintain ID. If lost, inform pilot & re-Id asap.

Question 9

What are the rules regarding traffic information under a TS?

Answer 9

Controller shall pass TI on relevant traffic & update if it continues to constitute a definite hazard or if requested by the pilot. High workload/RTF May reduce the ability to pass this info.

Traffic is relevant when (in the controllers judgement) 3nm or 3000’. Controllers may decide when not relevant (passing behind or diverging). Aim to pass TI by 5nm for pilot to meet collision avoidance and to allow update if necessary.

Controller judgement is essential to ensure TI is relevant and timely.

Distances on displays can be at variance to actual distances due to accuracy. Some aircraft may not be displayed.

Deconfliction is not provided. If pilot requires deconfliction advice, a DS shall be requested. The controller shall make all reasonable efforts to comply ASAP.

When providing headings/levels for positioning/sequencing controllers are not to knowingly introduce a risk of collision. Deconfliction minima is not required & pilot remains responsible for collision avoidance.

Question 10

What are the rules regarding terrain for the provision of a TS?

Answer 10

Subject to surveillance coverage,
TS may be provided below TSL, pilot is responsible for terrain clearance.

Other than a notified IF procedure, pilot shall be reminded that he remains responsible for terrain clearance.

Question 11

What are the rules regarding heading & level allocation under a TS?

Answer 11

Pilot may operate own nav or controller may provide headings for positioning, sequencing, or nav assistance.

When operating own nav, pilots may alter course as required but, unless safety is likely to be compromised, shall not change general route without advising & 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 & obtaining a response from the controller as aircraft may be co-ordinated against other airspace users.
If a heading is unacceptable, he shall advise the controller immediately.
Pilots remain responsible for collision avoidance when under ATC headings & will inform the controller if required to deviate for rules of the air
Controllers will only allocate headings above the units terrain safe level, however headings may be provided below TSL but the pilot is to be reminded.

Pilots may select their own levels or be allocated them by ATC for positioning and/or sequencing or for nav assistance. If a level is unacceptable he shall advise the controller. Unless safety is likely to be compromised, the pilot shall not change level or level band without informing the pilot & getting a response.
Pilots remain responsible for collision avoidance. Levels allocated shall be terrain safe unless an agreement is reached, or levels form part of a vfr clearance that requires flight below TSL, in which case the pilot shall be informed.

Question 12

What is DS?

Answer 12

Surveillance based ATS, in addition to the provisions of a BS, the controller will provide surveillance derived TI and issues headings or levels aimed at achieving DS minima, or for positioning or sequencing.

Avoidance of other traffic is ultimately the pilots responsibility.

Question 13

What conditions are required for the provision of a DS?

Answer 13

Controller with access to a surveillance system

Only IFR outside CAS irrespective of Met conditions. Pilot will be expected to accept flight in IMC, if not able; should not request a DS unless the flight can continue in VMC.

Pilots operating VFR shall request TS or BS

Controller will ID, inform the pilot and maintain ID. If lost, re-ID asap.

Question 14

Under what circumstances can controllers provide vectors below the unit terrain safe level when controlling R-Vis or SPC?

Answer 14

Max 500’ below TSL without reference to terrain when:

R-Vis within 10nm of the aerodrome

SPC within 10nm of the aerodrome

Avoid vectoring towards higher areas of the RVC if this will result in the A/c being more than 500’ below RVC level.

Question 15

What are the separation minima for air systems conducting R-Vis and RSI approaches?

Answer 15

Deconfliction minima to be applied until:

Point of confliction is within the MATZ or CCZ

R-Vis traffic is visual with instrument traffic

R-Vis traffic has been called to the instrument traffic

Civilian should be exceptional rather than routine.

Question 16

What are the lateral separation criteria?

Answer 16

5nm unless otherwise required (safety/technical) for:

All flights in class A
IFR in class C, D, E
IFR and VFR in class C (or E at the request of the pilot)
IFR and SFVR
SVFR

Class G: lateral separation is pilots responsibility but when providing DS, controllers should provide information and advice to achieve DS minima.

Question 17

When may standard lateral separation be reduced?

Answer 17

Down to 3nm when

Within assured radar range

Mil-mil coord or same controller

Update rate of 5s or greater

Outside CAS other than Class D or TRA’s

Question 18

Can reduced lateral separation be applied when operating SSR alone?

Answer 18

NO!

Question 19

What are the rules regarding reduced lateral separation between formations?

Answer 19

Should not be applied as formations may be displaced by up to 1nm (except where covered by a safety assessment)

Question 20

What vertical separation is required:

Using Mode C without coord?

Following coord?

Answer 20

Inside CAS: 5000’

Outside CAS: 3000’ & the blips shouldn’t merge (NTBU for 0000)

Once coordinated:

Subsonic:
Up To FL290: 1000’
Above FL290: 2000’

Supersonic:
Up to FL450: 2000’
Above FL450: 4000’

Question 21

When may standard vertical separation be reduced in terminal radar?

Answer 21

Reduced to 500’ when:

Lateral limits of assured radar coverage

Mil-mil coord or same controller

Below FL100 outside CAS other than class D

Question 22

Can reduced vertical separation be applied to civil air systems

Answer 22

Exception rather than the rule

Question 23

Can reduced vertical separation be applied to formations?

Answer 23

No, elements may be displaced by up to 100’

Question 24

What are the rules for applying RVSM in Area Radar?

Answer 24

Controllers may apply 1000’ RVSM within the vertical and lateral limits of RVSM airspace or transition airspace provided:

Both air systems are RVSM approved

Surveillance display shows RVSM status of all systems involved and air systems are coordinated by standing agreement or verbal

RVSM should not be applied to formations unless covered by a safety assessment as units may be displaced by up to 100’

Question 25

When would you reduce deconfliction advice or traffic information?

Answer 25

High traffic density

High workload

Lateral/vertical limits of solid radar coverage

Suspect performance of radar

Cluster environment (jamming, echoes, weather)

SSR only

Question 26

What actions must be taken when reducing deconfliction advice & traffic info?

Answer 26

Inform the pilot of reduction, reason and duration

Question 27

How is relative movement of conflicting traffic to be described?

Answer 27

Crossing

Converging

Same direction

Opposite direction

Manoeuvring

Question 28

What are the approved methods of ID using SSR?

Answer 28

Pilot sets 4 digit code.

Previously assigned 4digit code

Observing IDENT - not to be used for 7000.

Question 29

What are the approved methods of ID using position reports?

Answer 29

Over exact reporting point displayed on the radar map,

<30nm from vor/dme or TACAN displayed on the radar map

Below 3000’ Over notified VRP displayed on the radar map visual with the surface

By df fix (with another method if necessary)
Caution with:
Other radar returns
Inaccurate reporting if high or at range

Question 30

What are the approved methods of ID using the departing aircraft method?

Answer 30

Pre-noted
Within 1nm of the end of the runway

Caution with aircraft overflying, low approaching, departing from an adjacent runway or holding overhead.

Question 31

What are the approved methods of Air System ID using the turn method?

Answer 31

Ascertain heading
Period of track observation
30* or more.

Approximate position: 2 x turns of 30* or more

Verify only one radar return alters course

Caution within areas regularly used as turning points

Take account of radar system in use

Ensure not to turn outside coverage, into airspace etc

Turns using DF: one turn & relevant DF indication. Range info from DME, TACAN etc

Question 32

What factors must be taken into account when turning an a/c for ID?

Answer 32

Airspace restrictions

Terrain

Other radar returns

Surveillance coverage

Positioning turns

Question 33

What can what can be assumed if a controller is unable to locate a free-calling Air System.

Answer 33

Outside radar coverage; climb, call later or call another agency

Obscured by clutter; select alternative radar, change heading or call another agency

Reported position incorrect; further position check, if unresolved, UK emergency fixer service

Question 34

What are the rules regarding descent below TSL?

Answer 34

Take account of TSL & only descend when authorised under a specific procedure or:

In support of emergency,

Pilot is visual with the surface

Pilot is using terrain following equipment

Operating to/from a ship iaw BRd766

Question 35

In Class G, who is responsible for terrain clearance?

Answer 35

In accordance with the FIS being provided

DS: only at or above ATC TSL, other than on departure or following a notified approach procedure

TS May be provided below ATC TSL, pilots remain responsible at all times. Other than when following a notified procedure, a pilot shall be reminded that he remains responsible for terrain clearance.

Question 36

What are the rules regarding terrain clearance for VFR AND SVFR inside CAS?

Answer 36

Controllers have no responsibility for terrain clearance for VFR or SVFR inside CAS even if they accept vectors. Controllers should not however allocate levels.