What “cleared for takeoff” means

The definition, as the FAA writes it

From the Pilot/Controller Glossary, entry CLEARED FOR TAKEOFF (P/CG):

ATC authorization for an aircraft to depart. It is predicated on known traffic and known physical airport conditions.

“Predicated on known traffic and known physical airport conditions” is the controller telling you what the clearance rests on: what the tower can see and has been told. It is an authorization, not a report that the runway and the departure path are clear of everything; your look down the runway before you roll is still yours to make.

The phrase it is confused with

The clearance students most often mistake for a takeoff clearance is the one that comes just before it. The glossary entry for LINE UP AND WAIT (LUAW):

"Line up and wait" tells a pilot to taxi onto the departure runway, line up and wait. It is NOT authorisation for takeoff; it is used when takeoff clearance cannot immediately be issued.

So the sequence at a busy tower is: “line up and wait” — you taxi onto the runway and stop — then, when the traffic the tower was waiting for has cleared, “cleared for takeoff”. Nothing moves on the second part until you hear those words.

What to read back

A takeoff clearance carries a runway assignment, and the AIM (4-4-7 b) says the initial readback includes it — left, right or center included — with your call sign:

Pilots of airborne aircraft should read back the parts of ATC clearances and instructions containing altitude assignments, vectors or runway assignments. Include the aircraft identification in ALL readbacks and acknowledgements. Read back altitudes, altitude restrictions and vectors in the same sequence as given. The initial readback of a taxi, departure or landing clearance should include the runway assignment, including left, right or center.

Tower: “Skyhawk three alpha bravo, runway one six, cleared for takeoff.”

You: “Runway one six, cleared for takeoff, Skyhawk three alpha bravo.”

If the tower adds a departure instruction — a heading to fly, an altitude — it goes in the readback too, in the order it was given. And if you are not ready when the clearance comes, say so: “unable” with the reason is a complete and correct answer, and the tower will re-sequence you.

Practice it at a real tower

Virtual ATC opens tuned to the tower, on today’s METAR, at any US airport — for example Van Nuys (KVNY), Boeing Field (KBFI), Zamperini Field (KTOA) and Westchester County (KHPN).