Airspace, Oceanic Control and Separation

Question 1

What are the 2 main categories of airpspace?

Answer 1

Controlled and uncontrolled.

Question 2

What does classification of airspace within an FIR determine? (2)

Answer 2

1. ) Rules which apply.

2. ) Minimum services to be provided.

Question 3

How many Classes of controlled airspace are there in the UK and what are these?

Answer 3

There are 4 Classes of controlled airspace in the UK; these are Classes A, C, D and E.

Question 4

How many Classes of uncontrolled airspace are there in the UK and what are these?

Answer 4

There is only one Class of uncontrolled airspace in the UK and this is known as Class G.

Question 5

What is the primary reason why controlled airspace is provided?

Answer 5

To protect users (mostly commercial airliners).

Question 6

ACFT which fly into controlled airspace must be __________________ and their pilots must hold the necessary _____.

Answer 6

1. ) Equipped to certain standard.

2. ) Qualifications.

Question 7

Pilots must obtain _____ to enter controlled airspace and must follow ATC instructions _____ except in __________.

Answer 7

1. ) Clearance.
2. ) Implicitly.
3. ) Emergency Situations.

Question 8

Describe Class A airspace (4)

Answer 8

1. ) It is the most strictly regulated airspace where ACFT must comply with ATC instructions at all times.
2. ) Only IFR flight is permitted.
3. ) ACFT are separated from all other traffic.
4. ) Users are mainly airliners and business jets.

Question 9

Describe Class C airspace (3)

Answer 9

1. ) In the UK it extends from FL195 to FL660.
2. ) Both IFR and VFR flights are permitted.
3. ) Clearance is required to enter and compliance with ATC instructions is mandatory.

Question 10

Describe Class D airspace (3)

Answer 10

1. ) Both IFR and VFR flights are permitted.
2. ) Clearance is required to enter and compliance with ATC instructions is mandatory.
3. ) Control Areas around ADs are Class D and in Class D airspace, a speed limit of 250 knots applies to all ACFT below FL100.

Question 11

Describe Class E airspace (3)

Answer 11

1. ) Both IFR and VFR flights are permitted.
2. ) IFR traffic requires clearance to enter and compliance with ATC instruction is mandatory for separation purposes.
3. ) VFR traffic does not require clearance to enter.

Question 12

Controlled airspace is also divided by type depending on the function it provides. These types are…(5)

Answer 12

1. ) Aerodrome Control Zones.
2. ) Control Areas.
3. ) Terminal Control Area.
4. ) Airways.
5. ) Upper Air Routes (UARs)

Question 13

What is the purpose of an Aerodrome Control Zone?

Answer 13

To afford protection to ACFT in the immediate vicinity of aerodromes.

Question 14

What is the purpose of a Control Area and where are they situated?

Answer 14

They afford protection over a large area to a specified upper limit. They are situated above Aerodrome Traffic Zones (ATZ).

Question 15

Where are Terminal Control Areas normally established?

Answer 15

At the junction of airways in the vicinity of 1 or more aerodromes.

Question 16

An example of a Terminal Control Area is the London Terminal Control Area. It deals with arriving and departing ACFT from a number of aerodromes. Name these aerodromes. (10)

Answer 16

Biggin Hill, Farnborough, Gatwick, Heathrow, London City, Luton, Northolt, Southend, Stansted and other minor airfields in the London area.

Question 17

What are Airways and what are their typical dimensions?

Answer 17

1. ) Corridors of airspace connecting Terminal Control Areas and also link with Airways in other countries.
2. ) They are normally 10nm wide with a base between 5000ft and 7000ft, extending up to 24500ft.

Question 18

Where are Upper Air Routes situated and what are their vertical limits? Civil and Military ACFT operating above _____ are subject to a full and mandatory __________________.

Answer 18

1. ) UARs sit above airspace.
2. ) Usually FL250-FL460.
3. ) FL245.
4. ) Air Traffic Control service.

Question 19

Describe Class G airspace (3)

Answer 19

1. ) ACFT may fly when and where they like subject to a simple set of rules.
2. ) Although there is no legal requirement to do so, many ACFT notify ATC of their presence and intentions.
3. ) Pilots take full responsibility for their own actions although they can ask for help.

Question 20

Although avoidance of other ACFT remains the responsibility of the pilot, a number of services are available in uncontrolled airspace which offer various degrees of protection. How many of these services are there and what are their names?

Answer 20

There are 5:

1. ) Deconfliction Service.
2. ) Traffic Service.
3. ) Basic Service.
4. ) Alerting Service.
5. ) Procedural Service.

Question 21

What is an Alerting Service?

Answer 21

An Alerting Service is provided to notify appropriate organisations regarding ACFT in need of search and rescue aid and assist such organisations as required.

Question 22

What is a Procedural Service?

Answer 22

A Procedural Service is a non-radar based service in which deconfliction advice is provided against other ACFT receiving procedural service from the same controller.

Question 23

Where is Shanwick Oceanic Control based?

Answer 23

Prestwick.

Question 24

Which other countries does Shanwick Area Control share ATC responsibility with over the North Atlantic? (4)

Answer 24

Portugal, the USA, Canada and Iceland.

Question 25

What area over the North Atlantic is NATS responsible for?

Answer 25

The Eastern portion of the North Atlantic which stretches between 45 and 61 degrees North latitude and Westward towards longitude 30 degrees West.

Question 26

How is voice communication maintained over the North Atlantic?

Answer 26

Via HF (High Frequency) radio based at Shannon in the West of Eire.

Question 27

How often are position reports usually made by the pilot when over the North Atlantic?

Answer 27

Every 10 degrees of longitude.

Question 28

How often are the North Atlantic tracks reorganised by the relevant OACC and why is this done?

Answer 28

Every 12 hours to accommodate as many ACFT as possible on their most economic flight path.

Question 29

Which OACC is responsible for the Westbound North Atlantic Track system?

Answer 29

Prestwick OACC in Scotland.

Question 30

Which OACC is responsible for the Eastbound North Atlantic Track system?

Answer 30

Gander OACC in Canada.

Question 31

The Westbound North Atlantic Track System is usually through UK Airspace between which times?

Answer 31

1000 and 1600.

Question 32

Why are prevailing winds/jet streams taken into account when organising the North Atlantic Tracks?

Answer 32

So airlines can take advantage of tailwinds which are more fuel economical and gets the ACFT and passengers to their destinations quicker.

Question 33

What will clearance to cross the ocean include? (4)

Answer 33

1. ) Track.
2. ) Flight Level.
3. ) Speed.
4. ) Any time restrictions for entry to the track structure.

Question 34

How is adequate capacity for the anticipated demand for use of the North Atlantic Track system achieved?

Answer 34

Planners on either side of the ocean will consult with each other and coordinate as necessary with adjacent OACCs as well as domestic ATC agencies.

Question 35

__________ is installed at _____ which ensures that ATCO’s are able to detect and resolve _____ on oceanic tracks and issue safe _____ to participating traffic.

Answer 35

1. ) Modern equipment.
2. ) Prestwick.
3. ) Conflictions.
4. ) Clearances.

Question 36

There are _____ tracks on the North Atlantics Track system labelled __, __, __, __ and __.

Answer 36

1. ) 5.

2. ) A, B, C, D and E.

Question 37

How are ACFT separated on the North Atlantic Track System? (3)

Answer 37

1. ) 60 Nautical Miles between ACFT on the same level.
2. ) 10 minutes between ACFT on the same level and on the same track.
3. ) 1000ft vertical separation in RVSM (Reduced Vertical Separation Minima) airspace.

Question 38

In _____ airspace, each ACFT is separated from all other ACFT to _______________.

Answer 38

1. ) Controlled.

2. ) Internationally agreed standards.

Question 39

How is correct separation achieved?

Answer 39

By allocating ACFT different heights or by issuing headings (vectors). This is so ACFT can be at the same height but a minimum horizontal distance apart. Rules vary depending on where the ACFT is flying.

Question 40

How are ACFT under radar control separated in the LTCA?

Answer 40

They must be separated by 3 nautical miles from other ACFT at the same level. If less than this then they must be separated vertically by a MNM of 1000ft.

Question 41

How are ACFT separated outside of the LTCA in UK airspace?

Answer 41

They must be separated by 5 nautical miles from other ACFT at the same level. If less than this then they must be separated vertically by a MNM of 1000ft up to FL290. 1000ft separation may continue after FL290 up to FL410 if the ACFT is suitably equipped to comply with RVSM. Otherwise, 2000ft should be applied after FL290.

Question 42

NATS were at the forefront of introducing Reduced Vertical Separation Minima (RVSM). What is RVSM?

Answer 42

ACFT that have had the altimeters checked to high degree of accuracy and which can comply with other strict criteria can fly across the North Atlantic Track structure with only 1000ft separation above FL290 and below FL410. This standard allowed many more ACFT to fly through airspace where RVSM is allowed.