Aerodrome control

What this position is responsible for

The controller is responsible for aerodrome traffic. That means aircraft and vehicles on the manoeuvring area, and aircraft flying in the vicinity of the aerodrome. The manoeuvring area is the runways and the taxiways used for take-off, landing, and taxiing. It does not include the apron, where aircraft park at the stands.

The apron is not always the tower's job. Some airports have a separate apron service, and the boundary between that service and the tower is set locally. The terminal building, and the airline's own ramp work, are not aerodrome control.

The runway, then the taxiways

The runway in use follows the wind. Many airports also apply a local rule, such as a noise preference, when the wind allows it. Landings, take-offs, and the taxi routes are all built around that runway until it changes. A runway change is ordinary work. It changes who is next, which way aircraft taxi, and the direction the approach unit is sequencing.

On the runway the controller clears an aircraft to line up, to take off, to land, to cross, or to backtrack. The job is to clear that movement only when the runway is available for it. What counts as available is set by the rules of that state and that airport.

On the taxiways the controller clears a route. Outbound, that is from the edge of the apron to the holding point. Inbound, it is from the runway to the stand, or to the point where the apron service takes the aircraft. At a busy airport this is often a separate ground position. At a quiet one the same person works the runway and the taxiways.

Vehicles use the same surface. A runway inspection, snow clearance, or a rescue vehicle enters the runway only when it is cleared, and it reports when it is clear. The controller treats that vehicle as traffic.

Arrivals, departures, and the circuit

An arrival is usually transferred from approach already in the landing order. The tower lands it, or sends it around if the runway is not available. A missed approach goes back to the approach unit to be sequenced again, where a separate approach unit exists.

Departures wait at the holding point until the runway and the climb ahead of them are free. Once the aircraft is airborne and clear of the circuit, it is transferred on. At many airports that transfer is to approach. At a smaller airport the tower may work a combined service and transfer the flight onward itself.

A circuit flight can stay with the tower for the whole detail. It never needs the approach unit or an area sector. The tower sequences it with the other aircraft using the runway.

How the seats are split

A busy tower splits the frequency so that one job does not block the other. Ground control taxis aircraft and vehicles. The runway controller works the runway and the circuit. A further position sometimes issues the route clearance before the aircraft taxis, so the runway frequency stays free for take-offs and landings.

None of those seats is guaranteed. A smaller tower is often one controller. The endorsement is for the aerodrome, and the roster says which seats that person works there.

The view, including when it is poor

The usual picture is the view from the tower cab. Some services use a remote tower: cameras show the aerodrome to a room that is not on the field. The decisions do not change. The controller still has to know who is on the runway.

In poor visibility the airport may restrict how aircraft and vehicles move. The controller applies the procedure published for that aerodrome. There is no single visibility figure that every airport uses.

The endorsement

A controller is checked out for that aerodrome. Another tower is another endorsement, even when the rating name is the same. Approach and area control are different ratings. Working this tower does not authorise either of them.

The airspace around the airport is approach control. Flights en route are area control. How the three fit together is the air traffic controller guide.