Term

squawk

Daniel MarkFounder & Editor, Aviatopia
Published Mar 1, 2026Updated Mar 1, 20261 min read

A four-digit transponder code assigned by ATC for radar identification — special codes (7500, 7600, 7700) indicate hijack, communication failure, or emergency.

aviation-glossary

Quick Facts

Type
ATC Communication Code
Definition
A four-digit transponder code assigned by ATC for radar identification
Used By
Pilots, ATC

Definition#

A squawk (or squawk code) is a four-digit octal code set on an aircraft's transponder for radar identification by ATC. The term also refers to the act of setting or transmitting this code.

Why It Matters Operationally#

Squawk codes allow ATC to identify individual aircraft on radar. Discrete codes are assigned to IFR flights. Emergency codes (7700 general emergency, 7600 lost comms, 7500 hijack) trigger immediate alerts.