Definition
Authorizations issued by air traffic control (ATC) that permit a pilot to begin and execute a specific instrument approach procedure to a runway or airport. An approach clearance typically names the procedure (for example, the ILS or RNAV (GPS) to a particular runway), and authorizes the pilot to descend on the published procedure once established on a segment of it, in accordance with the altitudes and routing depicted on the approach chart.
Plain English
It is ATC's permission to fly a specific instrument approach into an airport. Once you receive it, you are cleared to follow the published approach steps and descend as the chart shows.
Context Anchor
Heard on air traffic control radio calls during instrument flying, usually before the pilot starts down toward the runway using a published approach.
Derivation
Approach comes from an older French word meaning “to come near.” Clearance comes from “clear,” meaning free or open. In aviation, a clearance is not just that the path looks clear; it is official permission from air traffic control to do something.
Why Pilots Care
They provide the legal and operational authority to descend below published altitudes while maintaining separation from other aircraft and terrain.
Intuition Check
Do not read “clearance” as meaning “the airplane is guaranteed clear of all danger.” Here it means official permission from air traffic control, and the pilot still must fly the correct path and follow all limits.
Example Sentence 1
After checking in with approach control, the pilot received the approach clearance: 'Cleared ILS Runway 27 approach.'
Example Sentence 2
We held outside the approach clearance until the controller cleared us to start the procedure.