Class D airspace requirements
AIP ENR 1.1
The lateral limits of Class D control area steps are depicted with blue lines and a blue tint. The vertical limits of Class D are shown with blue labels (AIP GEN 3.2). Control zones have defined dimensions, and associated control area steps, with an upper limit of 4500 ft (AIP ENR 1.4 (Class D)).
Pilots must maintain two-way communications with the relevant ATC control tower whenever operating in Class D airspace (AIP ENR 1.4). For entry into Class D airspace, establishing two-way communications between the aircraft and ATC constitutes a clearance for the pilot to enter the Class D airspace (AIP ENR 1.1).
Control area protection
For operations within Class C or D airspace, maintaining 500 ft above the lower limit of the CTA steps will provide a vertical buffer with aircraft operating in the adjoining airspace (AIP ENR 1.1).
Operating requirements for transponders
Pilots of aircraft fitted with a serviceable Mode 3A or Mode S transponder must have the transponder on Code 3000 or any assigned discrete code at all times during flight in Class D airspace. If the transponder is Mode C capable, that mode must also be operated continuously (AIP ENR 1.6).
Traffic information in controlled airspace AIP GEN 3.3
In controlled airspace, when a separation standard does not exist, ATC will provide traffic information to the aircraft concerned when, in the opinion of the air traffic controller, the information is warranted by the proximity of the aircraft.
The traffic information provided will contain as much information as is known and necessary to assist the pilot in identifying the other aircraft, for example:
- position, either by:
- clock reference
- bearing and distance
- relation to a geographical point or
- reported position and estimate and
- intentions or direction of flight.
In Class D airspace (AIP ENR 1.4):
- IFR flights are separated from other IFR and special VFR flights
- IFR flights receive traffic information in respect of VFR flights
- VFR flights receive traffic information in respect of all other flights and
- Special VFR flights are separated from other special VFR flights when visibility is less than VMC.
Aircraft operating in Class D airspace are not to exceed (AIP ENR 1.4):
- 200 kt at or below 2500 ft AAL within 4 nm of the primary Class D aerodrome and
- 250 kt when operating in other parts of Class D airspace.
Type of aircraft
Within Class D
|Distance from cloud||
1000 ft above, 500 ft below
ATC may permit operations in weather conditions that do not meet these criteria (Special VFR)
Source: AIP ENR 1.2
When operating under a special VFR clearance, pilots are responsible for ensuring that (AIP ENR 1.2):
- the flight is conducted clear of cloud<
- the visibility is not less than:
- aeroplanes: 1600 m
- helicopters: 800 m or
- balloons: 100 m below 500 ft AGL and 3000 m at and above 500 ft AGL
- a helicopter is operated at such a speed that the pilot has adequate opportunity to observe any obstructions or other traffic in sufficient time to avoid a collision; and
- the flight is in accordance with the low-flying requirements of CAR 157.