Like I stated above, Tower handles aircraft from about 15 miles out that is inbound to land. Towers may be asked to take over sooner or later than the 15 miles. It depends on the airport and the approaches in use. They also issue takeoff clearances to departing aircraft. Juggling aircraft taking off and landing, while maintaining separation can be challenging and pretty fun, all at the same time!

Time for that radio transmission example (I'm so predictable). This first on will be a pilot departing.

P: Detroit Tower, (callsign) holding short runway (xx).

C: (callsign) current altimeter (xx.xx), wind (xxx at xx), climb to (xxxx), fly runway heading, cleared for takeoff runway (xx).

P: Climb to (xxxx), fly runway heading, cleared for takeoff runway (xx) for (callsign).

The above sample is taking into consideration that there are no aircraft on final or ahead of the pilot. If an aircraft were ahead and just departing, you would wait for the aircraft on the runway to clear the start area and would then tell the holding aircraft to move onto the runway, but not takeoff.

Next will be a short sample of a position and hold situation.

C: (callsign) position and hold runway (xx).

P: position and hold runway (xx).

The controller would then assure a safe separation of aircraft(usually a couple miles) and then say:

C: (callsign) current altimeter (xx.xx), wind (xxx at xx), climb to (xxxx), fly runway heading, caution wake turbulence from departing (aircraft), cleared for takeoff runway (xx).

P: Climb to (xxxx), fly runway heading, cleared for takeoff runway (xx) for (callsign).

Logially, if a plane is on a short final(within 8 miles) and a plane is holding short, the controller would advise the holding pilot to continue to hold. I cannot stress this enough SAFE SEPARATION!