“Say again” in aviation? when is it used?

In aviation, “Say again” is a phrase used by pilots and air traffic controllers to request the repetition or clarification of a communication that was not understood or heard clearly. It is used to ask the speaker to repeat or rephrase their message for better understanding.

“Say again” is part of standard phraseology used in aviation communication and is used in various situations, such as:


If the pilot or air traffic controller did not understand a message due to unclear pronunciation, background noise, or other factors, they may use “Say again” to request the information to be repeated.

Pilot: “Tower, this is Flight 123, requesting clearance to land on runway 27.”
Controller: “Flight 123, Say again your request. You were not readable.”

ATC-Pilot Radio check
ATC-Pilot Radio check


If a pilot wants to confirm a specific instruction or clearance, they may use “Say again” to seek verification.

Controller: “Taxi to holding point Alpha for runway 09.”
Pilot: “Say again, holding point Alpha for runway 09?”


If a pilot or controller needs further clarification on a given instruction or message, they may use “Say again” to seek additional information.

Controller: “Turn left heading 270, descend to 3000 feet.”
Pilot: “Say again, heading 270, descend to 3000 feet?”

“Say again” is used to ensure clear and accurate communication in aviation, which is essential for safe and efficient operations. It is a standard phrase defined by International Civil Aviation Organization (ICAO) and is included in aviation phraseology and communication procedures documented in various references, including:

  1. International Civil Aviation Organization (ICAO) Doc 9432 – Manual of Radiotelephony: Provides guidance on radiotelephony phraseology, including “Say again” as a standard phrase for requesting repetition or clarification of messages.
  2. Federal Aviation Administration (FAA) Aeronautical Information Manual (AIM): Contains information on air traffic control procedures and phraseology, including the use of “Say again” in aviation communications.
  3. Airline Operations Control (AOC) Manuals: Airlines often have their own operational manuals that include guidance on standard phraseology, including the use of “Say again” in communication protocols.

It’s important for pilots and air traffic controllers to follow standard phraseology and use “Say again” when necessary to ensure clear communication and safe aviation operations.