Tower

Tower


Clearance		Apron / Ground		Tower		Terminal		Centre		Radio / FSS

Description

Tower controllers are responsible for the safety and separation of landing and departing traffic. They are also responsible for VFR traffic within the airport Control zone. It's the Tower controller that defines the active runways for a given airport, and ultimately decides who lands on which runway. The tower controls the upflow of traffic into controlled airspace, and is an essential link in the chain of ATS services. It is essential for Tower controllers to maintain constant contact with the Terminal/Centre controller, as well as ground.

Area of responsibility

The tower is responsible for all active runways, and for VFR traffic operating within the control zone (usually 5 or 7nm diameter Surface to 3000 AGL). Important: In some airports Tower will take responsibility of select taxiways - be sure to check the local procedures. When Clearance and Ground control is not online the Tower controller takes responsibility of the these positions as well.

What you need to know

In addition to the general guidelines a Tower controller must:

Be familiar with the Clearance delivery SOP;
Be familiar with the Apron/Ground control SOP;
Understand the different airspace divisions around the airport;
Understand any preferential runway assignments;
Understand noise abatement procedures when applicable;
Know all separation minima for arriving/departing traffic.

Procedures

Firstly you'll need the following information:

The sector file for the given airport;
The complete collection of charts for the selected airport.

If ground is online traffic will be handed over at or shortly before the holding position for the selected runway. If no ground is online aircraft should give you a call just before, or after pushback. In this situation you would assume the duties of the Ground controller.

Departing aircraft may be taxied into position at your discretion, but you have to request an IFR release from Terminal/Centre before you clear aircraft for take-off. Two different variations to the release are available:
- The first is a blanket release where Terminal/Centre places the responsibility of ensuring the initial separation of IFR traffic with the Tower. The required radar wake turbulence separation minima must be ensured by the Tower controller and is described in M533.2. In some large airports this agreement is permanent, and doesn't have to be co-ordinated.
- The second option consists of getting individual releases. This is commonly used at smaller airports, and if the Airspace above the airport is saturated.
Do not use conditional clearances or instructions for the movement of airport traffic, unless there is no possibility of misunderstanding. Misinterpretation could be caused by a conditional clearance or instruction such as: proceed across runway XX after departing DC9.
Only clear an aircraft to land when the preceding aircraft has:
1. Reported to you that he is clear of the given runway;
2. Ground relays to you the above report;
3. The preceeding aircraft is observed to be clear of the runway in IvAc. (Caution, due to sector errors aircraft may appear to be clear of the runway when the are not, and vice versa. If you give landing clearance without having received a report from the preceding aircraft, and the preceding aircraft is still within 500ft of the runway a point out should be given to the landing aircraft. "Air Canada 231, MD-83 clearing on X, Winds xxx/xx, cleared to land runway XX.)
4. You visually confirm that the aircraft is clear of the runway using IvAi.
It is your job to designate the active runway(s) according to wind, noise abatement procedures, and eventually ease of taxi. Refer to local airport procedures for local runway assignment procedures. (Where none exist use the longest/best serviced runway if winds are less than 5 knots, and take the crosswind component into account if wind is 5 knots or greater.
Be sure to keep all nearby ATC informed of runway and ATIS changes using the ATC channel.
When traffic / procedures permit try and accommodate requests for use of other runways. If using an inactive runway be sure to inform ground, as he may be using the runway to taxi aircraft.
Always respect minimum wake turbulence delay regardless of IFR releases. If you plan to have an aircraft take-off before the delay is complete ask him if he can accept before issuing the take-off clearance.

Hand off

Whenever possible anticipate hand-off to ground so that the aircraft won't have to stop. Don't wait for aircraft to report clear of the runway.
Hand off to Departures is with the take-off clearance, or once airborne is there is a need to keep the aircraft on your frequency for traffic (e.g. VFR traffic near the departure path). Some airport's procedures may vary, and should be respected.

Visual control

With the release of IvAi, which enables you to use your flight simulator to control visually ground control can become extremely realistic, especially as you will most likely see exactly where the aircraft is located as there are no sector errors. On the other hand FS scenery becomes an issue, so always interpret what you see with a grain of salt as far as aircraft on the ground are concerned.

IvAc settings

We recommend you use the NARDS colour scheme (available in the downloads section) with Ground detail, VORs, NDBs, Runway centrelines, LO airspace and LO airways turned on.
Set your altitude filter to the top of your control zone + 1200ft (e.g. CZ is SFC-3200; you would set the filter to SFC-4400ft), and use a range between 12 and 25nm, or as specified in the airport procedures.

See ATC school documentation on tower position.
See MANOPS section 300 for complete information.