ATC Conditional Clearance

An ATC (air traffic control) conditional clearance is a clearance issued by air traffic control that is subject to certain conditions. This type of clearance is issued to pilots in order to provide additional instructions or restrictions that must be met before the aircraft can proceed as authorized. Some common examples of conditions that may be included in an ATC conditional clearance include altitude restrictions, speed restrictions, departure line-up conditional clearance, and specific flight paths or routing instructions. These conditional clearances are an important tool for air traffic control to manage the flow of traffic and maintain safety in the air.

ICAO also specifies the precise format of a conditional clearance:

In all cases a conditional clearance shall be given in the following order and consist of:

a) identification;

b) the condition;

c) the clearance; and

d) brief reiteration of the condition,

For example:

“SXS 314, BEHIND A330 ON SHORT FINAL, LINE UP RWY 21 BEHIND”.

Note.— This implies the need for the aircraft receiving the conditional clearance to identify the aircraft or vehicle causing the conditional clearance.

(ICAO Doc 4444 – PANS-ATM: Chapter 12, para 12.2.7)