Let’s Be Careful Up There!

October’s EW Europe conference included presentations and discussions on how NATO sees aircraft integrated self-defence systems developing in the coming years.

Aircraft survivability was a focus of this year’s EW Europe conference and exhibition. EW Europe was hosted by the Association of Old Crows in Liverpool, northwest England, between 12th and 13th October.

The conference included a panel looking at aircraft survivability across the North Atlantic Treaty Organisation (NATO). This included discussion of NATO’s forthcoming Standardisation Agreement 4781, better known as STANAG-4781.

STANAG-4781 has two distinct strands: To ensure NATO nations can protect military aircraft in complex, hostile environments. To develop an open architecture to support the integration of sensors and effectors to this end. It is a framework to help NATO get ahead of the air defence threat presented by near-peer adversaries like the People’s Republic of China and Russia.

At the heart of the framework is a standard architecture known as NDAS (NATO Defensive Aids System). NDAS is intended to ensure that a DAS can receive threat information from multiple onboard and offboard sensors. The architecture will prioritise multiple threats and coordinate multiple countermeasure responses. Specifically, NDAS covers sensing and effectors, and gateways to an aircraft’s non-DAS functions and other systems. Datalinks will also be included to send and receive data pertinent to the threat environment. NDAS will manage countermeasures techniques and payloads. Above all, it will enhance survivability.


For example, a fighter might be advised of a specific radar threat via NATO’s emerging Cooperative Electronic Support Measure Operations (CESMO) protocol. CESMO allows ground-based radar parameters to be shared in real time between aircraft flying in the vicinity of the same radar threat. Sharing threat information is important so that an aircraft’s DAS can use the most appropriate response.

Several combat aircraft may have detected an Almaz-Antey 91N6 (NATO reporting name Big Bird) S-band (2.3 gigahertz/GHz to 2.5GHz/2.7GHz to 3.7GHz) ground-based air surveillance radar nearby. Each aircraft sends details of the radar’s location relative to its position over the CESMO link. The CESMO software triangulates this information and sends out data on the radar’s location.

The NDAS architecture will ensure that the aircraft’s self defence systems select the most effective response to the threat. This could be a specific jamming or deception waveform known to be effective against the 91N6’s target detection and tracking modes. Likewise, expendable radio frequency decoys like Leonardo’s BriteCloud could be programmed thus before launch.

FCAS and Tempest

Development of STANAG-4781 was completed in 2020. Its ratification is expected by all NATO’s members in 2022. The STANAG can be updated every six months. This will help account for new technologies and techniques pertinent to the NDAS as and when they appear.

It seems likely that the NDAS architecture will be adopted for the pan-European Tempest and FCAS (Future Combat Air System) programmes. The Tempest initiative includes Italy, Sweden and the United Kingdom, and involves BAE Systems, Leonardo and Rolls-Royce. FCAS involves France, Germany and Spain. Participants include Airbus, Dassault, Indra, MBDA, MTU, Safran and Thales. Prototype Tempest and FCAS sixth-generation combat aircraft should have performed their maiden flights by early next decade.

Ultimately the NDAS approach and STANAG-4781 stresses “efficiency, cost effectiveness and interoperability.”

by Dr. Thomas Withington