What are the main airspace categories within the FIRs?
- Controlled
- Uncontrolled
What does the airspace classification within a FIR determine?
- The rules which apply,
- The minimum services which are to be provided
How many and what are the airspace classes in the UK?
There are presently 5 classes of airspace.
- A, C, D and E are classes of controlled airspace
- Class G is outside controlled airspace
What are the requirements of controlled airspace?
- Aircraft which fly in controlled airspace must be equipped to a certain standard
- Pilots must hold the necessary qualifications
- Pilots must follow ATC instructions implicitly, except in an emergency situation
Class A airspace
- Only Instrument Flight Rules (IFR) flights are permitted.
- The most strictly regulated airspace; pilots must comply with ATC instructions at all times.
- Aircraft are separated from all other traffic
Class C airspace
- Extends from FL 195 to FL 660.
- Both IFR and Visual Flight Rules (VFR) traffic operates
- Requires a clearance to enter the airspace and,
- Compliance with ATC instructions are mandatory
Class D airspace
- Both IFR and VFR
- ATC clearance is needed
- Compliance with ATC instructions are mandatory
- Control areas around aerodromes are Class D
- A speed limit of 250kts below FL100 applies
Class E airspace
- Both IFR and VFR
- IFR traffic requires ATC clearance and compliance with ATC instructions is mandatory
- VFR traffic does not require a clearance to enter class E airspace
Class G airspace
Uncontrolled airspace. Aircraft may fly when and where they like, subject to a set of simple rules.
No legal requirement to notify ATC of aircraft presence and intentions.
Pilots’s responsibility for their own safety and avoidance of other aircraft
What are the types of controlled airspace?
- Aerodrome Control Zones (CTR)
- Control Areas (CTA) - situated above Aerodrome Traffic Zone, protection of larger area to a specified upper limit
- Terminal Control Areas (TMA)
- Airways
- Upper Air Routes (UARs) or Upper Airspace
Terminal Control Areas
Normally established at the junction of airways in the vicinity of one or more major aerodromes. LTMA (or LTCA) deals with traffic arriving and departing from: - London Heathrow - Gatwick, - Luton, - Stansted - London City - Northolt - Biggin Hill - Southend - Farnborough and other minor airfields in the London area
What is an Airway?
Airways are corridors connecting the TCAs and link up with airways in other countries too.
- Normally 10 miles wide
- Have bases between 5,000 feet and 7,000 feet
- Extend upward to a height of 24,500 feet
What are Upper Air Routes (UARs) or Upper Airspace?
Sit above airways.
Vertical limits are usually FL 250-FL 460.
Both, civil and military aircraft above FL 245 are subject to full and mandatory ATC services
What services are available outside controlled airspace?
- Deconfliction Service
- Traffic Service
- Basic Service
Two other types of service are: - Alerting Service - is provided to notify appropriate organisations regarding aircraft in need of search and rescue aid and assist such organisations
- Procedural Service - is non radar-based service in which deconfliction advice is provided against other aircraft receiving a Procedural Service from the same controller.
How are aircraft separated?
In controlled airspace separation is achieved by allocating aircraft different heights or by issuing headings (vectors) so that aircraft can be at the same height, but a minimum horizontal distance apart.
What is the separation in LTMA (LTCA)?
In London Terminal Control Area aircraft operating under radar control must be separated 3NM from other aircraft at the same height.
If they are less than 3NM apart they must be separated by a minimum of 1,000ft.
What is the separation outside of LTMA (LTCA)?
Separated 5 Nautical Miles horizontally if they are below FL290 or 1000 feet vertically. until FL410, 2000ft vertically unless they have RVSM
What is RVSM
Reduced Vertical Separation Minima. Altimeters checked to a high degree to allow vertical separation be reduced between FL 290 ans FL 410. (1000ft separation)
