Squawk 7600

Squawk 7600 is the transponder code associated with a two-way radio communication failure. It tells air traffic control that the aircraft may be unable to receive or transmit normal radio communications. The code supports ATC awareness, but it does not replace the procedures that apply to the route, airspace, and phase of flight.

What it governs

A pilot experiencing a communication failure follows the aircraft checklist and applicable regulations and procedures. The pilot checks the radio, audio panel, headset, circuit breakers as permitted, alternate frequencies, and other communication methods without creating unnecessary workload. If the transponder is operating, selecting 7600 provides an important signal to ATC.

The correct route, altitude, and landing procedure depend on the flight rules and circumstances. A pilot should not rely on a short glossary description to determine the complete response. The FAA Aeronautical Information Manual contains the governing discussion.

Example

An aircraft loses two-way communication after receiving an IFR clearance. The pilot troubleshoots as directed by the aircraft procedures, sets 7600 if able, and continues using the applicable communication failure rules and published information. The details depend on the clearance, route, weather, and available navigation.

Why it matters

ATC can often infer an aircraft's status from the code, route, altitude, and observed behavior. The code alone does not establish that the aircraft has an emergency, nor does it tell ATC whether the aircraft can receive transmissions. Pilots should use every reliable method available to restore communication.

7600 is different from 7700, which indicates an emergency, and 7500, which indicates unlawful interference. Use the current official procedure for the actual event.

Related terms and tools

• Squawk 7700
• Squawk 7500
• FAA Aeronautical Information Manual