UK Introduces Squawk Code 7400 for Drones Losing Communication

The United Kingdom Civil Aviation Authority has activated squawk code 7400 exclusively for unmanned aircraft systems operating beyond visual line of sight. Effective May 7, 2025, the special transponder signal indicates a drone has lost communication with its remote pilot and is executing autonomous return procedures. This allows air traffic controllers to distinguish these units from manned aircraft experiencing radio failure or general emergencies.

Broader Regulatory Framework

The introduction distinguishes 7400 from existing codes such as 7600 for crewed radio loss and 7700 for life-threatening situations. Concurrently, broader drone regulations effective Jan. 1, 2026, require Remote ID for aircraft over 100 grams with cameras. Industry leaders including DJI support the transition to new UK class markings by the end of 2027 to align with these safety enhancements.

Analysts describe the code as a critical step for managing mixed manned and unmanned airspace. While not yet globally recognized by the International Civil Aviation Organization, the move follows precedents set by the U.S. Federal Aviation Administration in 2016. The regulations aim to resolve ambiguities regarding unidentified drones near controlled flight paths.