Circuit Operations

In the real world, circuit operations are generally confined to smaller uncontrolled or Class D aerodromes. On VATSIM, pilots may choose to fly circuits at any aerodrome, including major Class C aerodromes.

Clearance

At a Class C aerodrome, provide an explicit clearance to operate in the circuit area, alongside an altitude and a discrete squawk code.

Example

ABC is a VFR aircraft on the ground at Canberra that intends to conduct circuit training.
ABC: "Canberra Ground, ABC, request clearance for circuits"
CB SMC: "ABC, Canberra Ground, cleared to operate in the circuit area not above A030, squawk 0040"
ABC: "Cleared to operate in the circuit area not above A030, squawk 0040, ABC"
CB SMC: "ABC"

At a Class D aerodrome, a clearance to take-off is a clearance to operate within a Class D control zone, so an explicit airways clearance is not given.

Example

ABC is a VFR aircraft on the ground at Archerfield that intends to conduct circuit training.
ABC: "Archer Ground, ABC, Cessna 172, information F, on the Eastern Apron, request taxi, for circuits"
AF SMC: "ABC, Archer Ground, taxi to holding point B1, runway 28R"
ABC: "Holding point B1, runway 28R, ABC"
ABC changes to AF ADC frequency approaching the holding point.
ABC: "Archer Tower, ABC, ready runway 28R, for circuits"
AF ADC: "ABC, runway 28R, cleared for take-off"
ABC: "Runway 28R, cleared for take-off, ABC"

For aircraft that are already airborne, provide circuit joining instructions on first contact.

Example

DEF is a VFR aircraft inbound to Canberra that intends to conduct circuit training.
DEF: "Canberra Tower, DEF, overhead Hoskinstown, A040, information L, for circuits"
CB ADC: "DEF, Canberra Tower, join downwind runway 12, not above A030, squawk 2311"
DEF: "Join downwind runway 12, not above A030, squawk 2311, DEF"
CB ADC: "DEF"
After DEF has joined downwind.
DEF: "DEF, downwind, touch and go"
CB ADC: "DEF, cleared touch and go, make left circuit"
DEF: "Cleared touch and go, make left circuit, DEF"

Takeoff

The standard circuit is performed with left-hand turns (i.e. a "left circuit"). Right circuits, where all turns are made to the right, are sometimes required for traffic, terrain, or noise abatement considerations. For example, where parallel runways are in use, the right runway generally uses a right circuit, and the left runway a left circuit, in order to separate traffic.

Circuit directions are usually provided in ERSA, but if any doubt exists or a non-standard circuit is in use, provide the circuit direction with the take-off clearance.

Example

AF ADC: "ABC, runway 28R, cleared for take-off, make left circuit"
ABC: "Runway 28R, cleared for take-off, make left , ABC"

Landing

After becoming airborne and making the turn to crosswind and then downwind, the pilot will report their position with intentions. There are a number of different requests a pilot may make at this point:

1. a touch and go, where the aircraft makes a landing and then immediately takes off again, continuing within the circuit;
2. a stop and go, where the aircraft makes a landing, comes to a complete stop on the runway and then takes off again, continuing within the circuit;
3. a full-stop landing, where the aircraft makes a normal landing and exits the runway; or
4. the option, which is the pilot asking for the option to make either of the above three manouvers at their own discretion, without any further clearance.

Example

ABC: "ABC, downwind, touch and go"
AF ADC: "ABC, cleared touch and go"
ABC: "Cleared touch and go, ABC"

Depending on the traffic situation, you may approve the pilots request, or else require that they make a full-stop landing.

Example

ABC: "ABC, downwind, request the option"
AF ADC: "ABC, make full stop due to traffic, cleared to land"
ABC: "Cleared to land, ABC"

Sequencing

In Class C airspace, separation is required between IFR and VFR aircraft. In Class D airspace, separation is only required between IFR aircraft (and SVFR aircraft in IMC). Nevertheless, controllers should still make all efforts to ensure an expeditious flow of traffic between aircraft in the circuit as well as aircraft arriving at the aerodrome from elsewhere.

ADC are not permitted to vector aircraft, but there are a number of other tools available to help segregate aircraft within the circuit.

Warning

The use of these tools in no way diminishes the responsibility of VFR aircraft to see and avoid, nor does it relieve the controller of the responsibility to pass traffic information where applicable.

An ADC may issue instructions for a pilot to make a longer or shorter approach, or to explicitly extend their downwind leg, so as to either pass in front of or behind another aircraft.

A straightforward way of accomplishing this with minimal added workload is to instruct the aircraft to "follow" the leading aircraft. In order to do this, the following aircraft must report having the leading aircraft in sight.

Example

ABC is downwind on runway 16L at Sydney while QFA1254 is established on a 3 mile final for the same runway.
ABC: "ABC, downwind, touch and go"
SY ADC: "ABC, traffc is a 737 on a 3nm final, runway 16L, report sighting"
ABC: "Traffic in sight, ABC"
SY ADC: "ABC, follow the 737, caution wake turbulence"
SY ADC: "Follow the 737, ABC"
Remember to pass traffic information to both aircraft.
SY ADC: "QFA1254, traffic is a Citation on a left downwind, they'll pass behind you, runway 16L, cleared to land"
QFA1254: "Runway 16L, cleared to land, QFA1254"
Some time later, after QFA1254 has vacated the runway and a wake turbulence standard has been achieved.
SY ADC: "ABC, runway 16L, cleared touch and go"
ABC: "Runway 16L, cleared touch and go, ABC"

An ADC may issue an instruction for a pilot to make a complete 360 degree orbit, either left or right, to delay the aircraft in place.

Example

DEF, a Cessna 172, is on a left downwind on runway 30 at Canberra, while UEM, a Baron, is joining left base.
DEF: "DEF, downwind, full-stop"
CB ADC: "DEF, make one right hand orbit"
DEF: "One right hand orbit, DEF"
CB ADC: "UEM, runway 30, cleared to land"
UEM: "Runway 30, cleared to land, UEM"
Once the controller observes that DEF's orbit is complete.
CB ADC: "DEF, traffic is a Baron on base, runway 30, report sighting"
DEF: "Traffic in sight, DEF"
CB ADC: "DEF, follow the Baron"
DEF: "Follow the baron, DEF"
Some time later, after UEM has vacated the runway.
CB ADC: "DEF, runway 30, cleared to land"
DEF: "Runway 30, cleared to land, DEF"

An ADC may change the runway for an aircraft in the circuit, so as to separate circuit traffic from non-circuit traffic, or to segregate aircraft with different performances for better traffic flow.

Note

Do not offer a change of runway to an aircraft below 500ft AGL on final.
You may approve a pilot request for a change of runway for an aircraft established on final.

Example

ABC is on a right downwind on runway 16R at Sydney. QLK1834 is on a 7 mile final for the same runway.
ABC: "ABC, downwind, touch and go"
SY ADC: "ABC, change of runway, runway 16L, cleared touch and go, make left circuit"
ABC: "Change of runway 16L, cleared touch and go, make left circuit, ABC"