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IVAO United Kingdom > Controllers > Standard Procedures > Tower

Tower


Clearance Ground Tower Approach Radar Area FIS

Description

Tower controllers are responsible for issuing information and instructions to aircraft under their control to achieve a safe, orderly and expeditious flow of air traffic and to assist pilots in preventing collisions between aircraft flying in, and in the vicinity of the aerodrome traffic zone and aircraft taking off and landing.

In the absence of Ground and delivery controllers, Tower controllers will complete the tasks detailed in the Ground Movement Control and Delivery SOP's.

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 Air Traffic services. It is essential for Tower controllers to maintain constant contact with the Approach Radar/Area controller, as well as ground/delivery.

Area of responsibility

The tower is responsible for all active runways, and for traffic operating in and within the vicinity of the Aerodrome Traffic Zone (up to 2.5nm diameter, Surface up to 2000 AAL). Important: In most airports, the tower controller will be responsible for the runway access points - be sure to check the local procedures.

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 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.

Airspace

Controllers are to provide minimum services according to the classification of the airspace within which the aerodrome and associated aerodrome traffic zone is located.

    Class A - Effects of Weather

    At aerodromes situated in Class A airspace, ATC shall inform Special VFR flights when the reported meteorological visibility is less than 10 km. Pilots must be asked their intentions and, if necessary, IFR clearances given. Controllers should note that in such conditions continued flight according to SVFR is permitted if the pilot is appropriately licensed.

    Class A - Effects of Weather

    ATC shall advise pilots of aircraft, other than helicopters, intending to operate under VFR, inbound to or outbound from aerodromes in Class D airspace, if the reported meteorological visibility reduces to less than 5000 m and/or the cloud ceiling is less than 1500 feet.

    The controller should then ask the pilot which type of clearance is required and then give it to the pilot.

    Additionally, the controller shall not issue any further VFR clearances to aircraft, other than helicopters, wishing to enter the airspace for the purposes of taking off or landing at any airfield, situated within the Class D control zone, where the reported meteorological visibility is less than 5000 m.

Procedures

Firstly you'll need the following information:

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

The term "runway-in-use" is used to indicate the particular runway or landing direction selected as the most suitable. Normally, it should be the runway most closely aligned to the surface wind direction. (Aircraft take-off into the wind) Where the surface wind conditions are light and variable, the 2000ft wind should be taken into account.

When selecting the runway-in-use, other factors such as traffic pattern, the length of runways or landing runs and the approach aids available should be taken into account. At certain aerodromes more than one runway may be in use at any one time (Heathrow for example).

Should a change of runway be necessary, Tower must inform approach control, area control, and aircraft under their control.

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.

Line-up instructions may be issued to more than one aircraft at different points on the same or crossing runways provided that:

  • It is during daylight hours.
  • Aircraft are continuously visible to the tower controller.
  • Aircraft are on the same RT frequency.
  • Pilots are advised of the number of aircraft ahead in the sequence and the position/runway from which these aircraft will depart.
  • The physical characteristics of the runway do not render preceding aircraft in the departure sequence invisible to the succeeding aircraft on the same runway.

When line-up will take place at a position other than for a full-length runway departure the intermediate "holding point" designator shall be included in the line-up instruction.

The tower controller is responsible for issuing take-off clearance and advising pilots of any variations to the surface wind or other significant changes to met conditions. (In the real world, a 2 minute wind average is passed to pilots - For the purpose of IVAO, the wind indicated in the METAR should be passed unless the pilot requests an Instant wind read out. In this case, the wind indicated in the box also displaying the QNH should be passed, with the word "instant" preceeding it.

When multiple runways are in use and possibility of confusion exists, the take-off clearance shall include the designator of the departure runway. "Runway 27L, cleared for take-off".

Take-off clearance may be issued when aircraft is at or approaching the holding point for a runway.

If the take-off clearance has to be cancelled before the take-off run has commenced, the pilot shall be instructed to hold position and acknowledge the instruction. "BAW754, hold position, Cancel take-off - I say again, BAW754 cancel takeoff acknowledge".

If the take-off run has commenced and there is an important safety reason as to why the aircraft cannot take off, the pilot shall be instructed to stop immediately. "BAW754, stop immediately - I say again BAW754, stop immediately - acknowledge".

Some phraseology examples:

"BEE5666, via A1, line up runway 26"

"KLM754, via A1, line up runway 23, there will be a company 737 departing ahead of you from A3"

"KLM234, via A3, line up runway 23, there will be a company 737 on the runway departing after you from A1"

"BAW1887, runway 27L, cleared for take-off, surface wind 280 degrees 6 knots"

"IBE266, Cleared for take-off, surface wind 180 degrees 18 knots"

If for any reason, you need an aircraft to take off immediately, the instruction "Cleared for immediate take-off" may be added. It is expected that the pilot will act as follows:

  • At the holding point, taxi immediately onto the runway and commence take-off without stopping the aircraft (Not to be used with heavy aircraft).
  • If already lined up on the runway, take-off without delay.

You should always ask the pilot before giving the clearance if he is able to accept an immediate take-off.

Aircraft should be handed off to the next sector once airborne, preferably no later than 2000ft.

Traffic Circuit

Position 1 - Aircraft reports on "downwind" leg when abeam upwind end of the runway.

Position 2 - Aircraft reports "late downwind" if it is on the downwind leg, has been unable to report "downwind" and has passed the downwind end of the runway.

Position 3 - Aircraft reports "base" leg (if required).

Position 4 - Aircraft reports "Final". Clearance to land issued here.

Position 5 - Aircraft reports "long final" (Between 8 and 4 miles) when aircraft is on a straight-in approach.

Aircraft joining the circuit:

Clearance to enter the circuit is issued when the aircraft is still some distance from the airfield to enable the pilot to conform with the traffic circuit. Information concerning landing direction or runway in use and any other necessary instructions are given at the same time.

IFR Inbounds:

When multiple runways are in use, the landing runway clearance shall include the runway designator.

"Runway 27L, cleared to land, surface wind 250 degrees 8 knots".

Unless specific procedures have been approved, a landing aircraft shall not be permitted to cross the beginning of the runway on its final approach until a preceding aircraft, departing from the same runway, is airborne.

In the real world, a 2 minute wind average is passed to pilots - For the purpose of IVAO, the wind indicated in the METAR should be passed unless the pilot requests an Instant wind read out. In this case, the wind indicated in the box also displaying the QNH should be passed, with the word "instant" preceeding it.

Missed Approach:

If the runway is occupied by another aircraft or vehicle when an aircraft is on final approach, it must be instructed to carry out a missed approach. The correct phraseology to be used:

"FCA634C, go around, I say again, go around, acknowledge"

"Going around, FCA634C"

Aircraft should then be told to follow the published missed approach procedure, or an alternative clearence given which has been provided by the approach controller.

"FCA634C, follow the standard missed approach procedure, contact Director, 134.975"

Ensure you inform the Approach controller as soon as the aircraft begins the missed approach procedure.

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 pinch of salt as far as aircraft on the ground are concerned.

IvAc settings

We recommend you switch Ground detail, VORs, NDBs and Runway centrelines on.

Set your altitude filter to the top of your Aerodrome Traffic Zone + 1500ft (e.g. ATZ is SFC-2000; you would set the filter to SFC-3500ft), and use a range between 12 and 25nm.