A control tower is a building at an airport from which instructions are given to aircraft when they are taking off or landing. You can also refer to the people who work in a control tower as the control tower.
The pilot told the control tower that he'd run into technical trouble.
control tower in British English
noun
a tower at an airport from which air traffic is controlled
control tower in American English
a tower at an airport with radar, etc. from which air traffic is directed, chiefly by radio
Examples of 'control tower' in a sentence
control tower
The airport has no control tower and does not require pilots to check in with security.
Times, Sunday Times (2006)
Hear the airport control tower recording online.
The Sun (2009)
It is the serenity that strikes, as you enter an air traffic control tower.
Times, Sunday Times (2010)
A MAN wanted for deception triggered an airport security alert by getting into the air traffic control tower.