control tower

The 109-meter tall Vienna Airport control tower.

Inside the control tower at Misawa Air Base, Japan.

Field-deployable control tower

A control tower, or more specifically an air traffic control tower, is the name of the airport building from which the air traffic control unit controls the movement of aircraft on and around the airport. Most of the world's airports are non-towered or mandatory frequency — only a minority of airports have enough traffic to justify a control tower, though some airports may open temporary tower units during special events like the Oshkosh Airshow.

Permanent control tower structures generally rise high above other buildings at an airport to give air traffic controllers a view of aircraft moving on the ground and in the air around the airport, though temporary tower units may operate from trailers or even portable radios outside.

Medium-traffic airports may have only one controller staffing the control tower, and may not keep the tower open 24 hours per day. Busier airports usually have space for several controllers and other support staff, and operate 24 hours per day, 365 days per year.

Features

Full control tower structures usually have windows that circle the entire top floor, giving all round vision. The windows are usually tilted outwards, because otherwise the controllers would see the reflection of their equipment. The ceiling may also be painted black.^[1]

Control towers typically contain the following:

• radios for communication with aircraft, linked to controllers' headsets or to microphones and speakers;
• a telephone system that connects dedicated voice lines and public telephone lines via quick-dial systems to controllers' headsets, allowing them to talk to other controllers and outside parties;
• a strip board allowing Flight Progress Strips to be used (however in some towers these have been replaced by a computerised system);
• a light gun for communication with aircraft via aviation light signals in the event of a radio failure;
• wind and pressure gauges.

Other equipment may include the following:

• an aerodrome traffic monitor, which is a small radar display that is not used for separation purposes but allows controllers to see the aircraft flying in the vicinity of the airport;
• a surface movement radar displaying aircraft and vehicles on the airport to assist controllers at night and in poor visibility;
• computerized meteorological information, flight data and briefing systems.

Records

The world's highest control tower is Vancouver Harbour Control Tower, situated on top of the 142 meter skyscraper 200 Granville Square, in downtown Vancouver, Canada. The world's tallest free standing control tower is the 132.2 m (434 feet) Suvarnabhumi Airport control tower, 25 km east of Bangkok, Thailand.

Gallery

A surface movement radar at Schiphol airport, used to assist tower controllers at night or in poor visibility	London Luton Airport control tower	Stockholm-Arlanda Airport	George Bush Intercontinental Airport control tower
Oslo lufthavn, Gardermoen control tower at 91 meters	Sydney Airport control tower	The control tower of a small airfield: Kemble Airport, England	Malpensa International Airport control tower
Heathrow ATC Tower

References

Wikimedia Commons has media related to: Airport towers

1. ^ LiveScience.com Why Do Air Traffic Control Towers Have Slanted Windows?