Air Traffic Services

Question 1

What are the divisions of the air traffic services? (2.3.1)

Answer 1

1) area control service: the provision of air traffic control service for controlled flights, except for those parts of such flights described in 2.3.1 b) and c) in order to accomplish objectives a) and c) of 2.2;
2) Approach control service: the provision of air traffic control service for those parts of controlled flights associated with arrival and departure, in order to accomplish objectives a and c of 2.2
3) Aerodrome control service: the provision of air traffic control service for aerodrome traffic, except for those parts of flights described in 2.3.1 b, in order to complete objects a b and c of 2.2

Question 1

What are the objectives of air traffic service?

Answer 1

a) Prevent collisions between aircraft
b) prevent collisions between aircraft on the maneuvring area and obstructions in that area
c) expedite and maintain an orderly flow of traffic
d) provide advice and information useful for the safe and efficient conduct of flights;
e) notify the appropriate organizations regarding aircraft in need of search and rescue aid, and assist such organizations as required.

Question 2

Determination of the need for air traffic services

Answer 2

the need for the provision of air traffic services shall be determined by consideration of the following:
a) types of air traffic involved
b) the density of air traffic
c) the meteorological conditions
d) such other factors as may be relevant

Question 3

How is it determined how portions of airspace and controlled areas are designated?

Answer 3

When it has been determined that air traffic services will be provided in particular portions of the airspace or at particular aerodromes, then those portions of airspace or those aerodromes shall be designated in relation to the air traffic services that are to be provided.

Question 4

Explain all the designations a portion of airspace may receive.

Answer 4

FLight Information Regions: those portions of airspace where it is determined that flight information service and alerting service will be provided shall be designated as flight information regions

Control areas and control zones: those portions of the airspace where it is determined that air traffic control service will be provided to IFR flights shall be designated as control areas or control zones

Controlled aerodromes: those aerodromes where it is determined that air traffic control service will be provided to aerodrome traffic shall be designated as controlled aerodromes.

Question 5

How shall air traffic services be provided by flight information centers and air traffic control units?

Answer 5

The air traffic services shall be provided by units established and designated as follows:
1) Flight information centers shall be established to provide flight information service and alerting service within flight information regions, unless the responsibility of providing such services within a flight information region is assigned to an air traffic control unit having adequate facilities for the discharg of such responsibility.

2) Air traffic control units shall be established to provide air traffic control service, flight information service and alerting service within control areas, control zones and at controlled aerodromes

Question 6

Specification for flight information regions, control areas and control zones in terms of the delineation of airspace.

Answer 6

Recommendation - The delineation of airspace, wherein air traffic advisory services are to be provided should be related to the nature of the route structure and the need for efficient service rather than to national boundaries.

Question 7

How should air traffic services units and airspaces be identified?

Answer 7

Recommendation - An area control center or flight information center should be identified by the name of a nearby town or city or geographic feature

Question 8

Establishment and Identification of standard routes for taxiing aircraft

Answer 8

Recommendation - Where necessary, standard routes for taxiing aircraft should be established on an aerodrome between runways, aprons, and maintenance areas. Such routes should be direct, simple and where practicable, designed to avoid traffic conflicts
Recommendation - Standard routes for taxiing aircraft should be identified by designators distinctly different from those of the runways and ATS Routes.

Question 9

Coordination between the operator and Air Traffic Services**

Answer 9

Air traffic services units, in carrying out their objectives, shall have due regard for the requirements of the operators consequent on their obligations as specified in Annex 6, and, if so required by the operators, shall make available to them or their designated representatives such information as may be available to enable them or their designated representatives to carry out their responsibilities.

When so requested by an operator, messages (including position reports) received by air traffic services units and relating to the operation of the aircraft for which operational control service is provided by that operator shall, so far as practicable,be made available immediately to the operatior or a designated representative in accordance with locally agreed procedures.

Question 10

Coordination between military authorities and air traffic services

Answer 10

Air traffic services authorities shall establish and maintain close cooperation with military authorities responsible for activities that may affect flights of civil aircraft.

Question 11

Coordination between meteorological and air traffic services authorities. (+)

Answer 11

To ensure that aircraft receive the most up-to-date meteorological information for aircraft operations, arrangements shall be made, where necessaru, between meteorological and air traffic services authorities for air traffic services personnel.

Question 12

Coordination between aeronautical information services and air traffic services authorities

Answer 12

To ensure that aeronautical information services units obtain information to enable them to provide up-to-date pre-flight information and to meet the need for in flight information, arrangements shall be made between aeronautical information services and air traffic services authorities responsible for air traffic services to report to the responsible aeronautical information services unit, with a minimum delay:
a)information on aerodrome conditions;
b) the operational status of associated facilities, services and navigation aids within their area of responsiblity
c) the occurence of volcanic acticity observed by air traffic services personnel or reported by aircrafto; and
d) any other information considered to be of operational significance.

Question 13

Minimum flight altitudes (How are they determined and what shall they provide)

Answer 13

Minimum flight altitudes shall be determined and promulgated by each Contracting State for each ATS route and control area over its territory. The minimum flight altitudes determined shall provide a minimum clearance above the controlling obstavle located within the areas concerned.

Question 14

How shall time be expressed in air traffic services?

Answer 14

Air traffic services units shall use Coordinated Universal Time (UTC) and shall express the time in hours and minutes and, when required, seconds of the 24 hour day beginning at midnight.

Question 15

Service to aircraft in the event of emergency

Answer 15

An airacraft known or believed to be in a state of emergency, including being subjected to unlawful interference shall be given maximum consideration, assistance and priority over other aircraft as may be necessitated by the circumstances.

Question 16

Explain In flight Contingencies for strayed or unidentified aircraft

Answer 16

Should the ATS unit consider that a strayed or unidentified aircraft may be the subject of unlawful interference, the appropriate authority designated by the state shall immediately be informed, in accordance with locally agreed procedures.

Strayed Aircraft - an aircraft which has deviated significantly from its intended track or which reports that it is lost.
Unidentified aircraft - an aircraft which has been observed of reported to be operating in a given area but whose identity has not been established.

Question 17

What are air traffic control clearances based on?

Answer 17

Air traffic control clearances shall be based solely on the requirements for providing air traffic control service.

Question 18

What is the responsibility of air traffic services concerning the provision of aeronautical information to aeronautical information services?

Answer 18

The air traffic services responsible for the provision of raw aeronautical information/data to the aeronautical information service shall do so while taking into account accuracy and integrity requirements for aeronautical data as specified in appendix 6 of annex 11.

Question 19

What shall an air traffic control clearance indicate?

Answer 19

An air traffic control clearance shall indicate:
a) aircraft identification as shown in the flight plan;
b) clearance limit;
c) route of flight;
d) level (s) of flight for the entire route or part thereof and changes of levels if required;
e) any neccessary instructions on other matters such as approach or departure maneuvers, communications and the time of expiry of the clearance.

Question 20

What are the designations for those portions of airspace where it has been determined that ATC service will also be provided to VFR flights?

Answer 20

Those portions of controlled airspace wherein it is determined that air traffic control service will also be provided to VFR flights shall be designated as Classes B, C or D airspace.

Question 21

What shall Flight Information Regions be delineated to cover and what airspace shall it include?

Answer 21

Flight Information Regions shall be delineated to cover the whole of the air route structure to be served by such regions.
A flight information region shall include all airspace within its lateral limits, except as limited by an upper flight information region.

Question 22

How shall control areas be delineated?

Answer 22

Control areas including, inter alia, airways and terminal control areas shall be delineated so as to encompass sufficient airspace to conttain the flight paths of those IFR flights or portions thereof to which it is desired to provide the applicable parts of the air traffic control service, taking into account the capabilities of the navigation aids normally used in that area.

Question 23

How shall the upper and lower limit of a control area be established?

Answer 23

A lower limit of a control area shall be established at a height above the ground or water of not less than 200m(700ft).

An upper limit of a control area shall be established when either:
a) air traffic control service will not be provided above such upper limit; or
b) the control area is situated below an upper control area, in which case the upper limit shall coincide with the lower limit of the upper control area.

When established, such upper limit shall coincide with a VFR cruising level of the tables in appendix 3 to annex 2.

Question 24

What shall the lateral limits of a control zone encompass?

Answer 24

The lateral limits of a control zone shall encompass at least those portions of the airspace, which are not within control areas, containing the paths of IFR flights arriving at and departing from aerodromes to be used under instrument meterological conditions.

Question 25

How far should a control zone extend?

Answer 25

The lateral limits of a control zone shall extend to at least 9.3km (5NM) from the center of the aerodrome or aerodromes concerned in the directions from which approaches may be made.

If a control zone is located within the lateral limits of a control area, it shall extend upwards from the surface of the earth to at least the lower limit of the control area.

Question 26

Why shall significant points be established? How shall they be identified?

Answer 26

Significant points shall be established for the purpose of defining an ATS route or instrument approac procedure and/or in relation to the requirements of air traffic services for information regarding the progress of aircraft in flight.

Significant points shall be identified by designators.

Question 27

How shall air traffic services units provide military units with information?

Answer 27

Air traffic services units shall, either routinely or upon request, in accordance with locally agreed procedures, provide appropriate military units with pertinnent flight plan and other data concerning flights of civil aircraft. In order to eliminate or reduce the need for interceptions, air traffic services authorities shall designate any areas or routes where the requirements of annex 2 concerning flight plans, two way communications and position reporting apply to all flights to ensure that all pertinent data is available in appropriate air traffic services units specifically for the purpose of facilitating identification of civil aircraft

Question 28

`How should states establish procedures regarding use of airspace reserved for military or other special activities?

Answer 28

Recommendation - In order to provide added airspace capacity and to improve efficiency and flexibility of aircraft operations, States should establish procedures providing for a flexible use of airspace reserved for military or other special activities. The procedures should permit all airspace users to have safe access to such reserved airspace.

Question 29

What is the rule pertaining to the establishment of a State safety program?
Who establishes the acceptable level of safety?

Answer 29

States shall establish a State safety programme, in order to achieve an acceptable level of safety in civil aviation
The acceptable level of safety to be achieved shall be established by the state.

Question 30

What shall states require as part of their State safety program?

Answer 30

States shall require, as part of their State Safety programme, that an air traffic services provider implement a safety management system acceptable to the State that, as a minimum:
a) identifies safety hazards;
b) ensures the implementation of remedial action necessary to maintain agreed safety performance; and
c) provides for continuous monitoring and regular assesment of the safety performance; and
d) aims at a continuous improvement of the overall performance of the safety management system.

Question 31

What is the vertical reference system used?

Answer 31

Mean sea level (MSL) datum, which gives the relationship of gravity - related height (elevation) to a surface known as the geoid, shall be used as the vertical reference system for air navigation.

Question 32

Who shall Air traffic control service be provided to?

Answer 32

Air traffic control service shall be provided:
a) to all IFR flights in airspace Classes A,B,C,D and E;
b) to all VFR flights in airspace Classes B, C and D;
c) to all special VFR flights
d) to all aerodrome traffic at controlled aerodromes

Question 33

How shall the parts of air traffic control be provided?

Answer 33

The parts of air traffic control service described in 2.3.1 shall be provided by the various units as follows:
a) Area Control service:
1) by an area control center; or
2) by the unit providing approach control service in a control zone or in a control area of limited extent which is designated primarily for the provision of approach control service and where no area control center is established.
b) Approach Control Service:
1) by an aerodrome control tower or area control center when it is necessaryor desirable to combine under the responsibility of one unit the functions of the approach control service with those of tthe aerodrome control service or the area control service;
2) by an approach control unit when it is necessary or desirable to establish a seperate unit
c) Aerodrome control service: by an aerodrome control tower,