A US Air Force fifth-generation airborne identification friend or foe system has shown zero interference with European air traffic control in an overseas ground and flight testing onboard a Nato airborne warning and control system (AWACS).

The prototype waveform, mode 5-capable UPX 40 ground tested by Eurocontrol, was designed to interfere less with the US and international civil air traffic control functions.

The zero-interference capability is significant as the US and Europe civil air traffic control agencies won’t allow mode-5 use if it interferes with maintenance of aircraft safe separation standards.

Used on the AWACS, the interrogator radiates a waveform to determine information such as aircraft identification and altitude, and determines if aircraft are friendly or otherwise.

The mode-5 waveform identifies both military and civilian aircraft with range, bearing and elevation information, and also provides platform-specific information.

The system enables the USAF to pin-point targets in densely packed environments and also interoperates with other forces.

The US Defense Department and Nato forces are transitioning into mode-5 capability.

In July 2009, the mode 5 joint operational test approach will demonstrate the system’s capability to interoperate among differing platforms, military services and manufacturers.

The US Air Force is further developing mode-5 capability in preparation for a production decision in 2011.