Switzerland, new IRIS-T air defense systems

Switzerland plans to purchase at least four medium-range ground-based air defense systems IRIS-T SLM, produced by the German company Diehl Defence. This was announced by Armasuisse, the Federal Office for Defense Procurement, confirming that negotiations with the manufacturer are currently in an advanced stage.

The contract signing is expected in the third quarter of 2025, as part of the European program European Sky Shield Initiative (ESSI), which Switzerland joined last October as the fifteenth member country, with an initial focus on medium-range air defense.

In 2023, the Swiss Parliament approved a credit guarantee of 660 million Swiss francs (approximately 809 million dollars) to support the acquisition as part of the 2024 armament program. The decision is part of the growing European commitment to strengthening defensive capabilities, in response to ongoing missile and drone attacks by Russia against civilian and military targets in Ukraine.

“The future ground-based air defense will significantly contribute to maintaining airspace sovereignty and protection from long-range weapon attacks,” stated Armasuisse. The new system will be integrated into the national air defense network, as part of the integrated air defense (IAD).

Operational tests in mountainous environments: TRML-4D radar under examination

A crucial step in the acquisition process was taken between March 31 and April 11, 2025, with a series of tests on the TRML-4D radar provided by Hensoldt, conducted in collaboration with Diehl Defence and the Swiss Armed Forces.

The tests were conducted in two strategic locations: the federal site of Homberg and the Emmen airfield, to verify the system's performance in Switzerland's complex mountainous topography — where over 70% of the territory is covered by elevations, and a quarter is above 2,000 meters altitude.

The radar demonstrated detection and classification capabilities on various types of aircraft, including PC-12, PC-7, F/A-18, and helicopters, operating in the usual training spaces. Additionally, checks were conducted on electromagnetic compatibility with civilian systems, such as weather radars.

No firing tests were conducted, but the use of a radar target simulator allowed testing of the sensor's capability in the presence of targets with different speeds and radar cross-sections.

Exposure to non-ionizing radiation (NIR) remained within the limits set by Swiss regulations: Armasuisse operated with a regular transmission authorization issued by the Federal Office of Communications (OFCOM).

Filling the gaps: the role of the IRIS-T SLM system

The “GBAD MR” (Ground-Based Air Defence Medium Range) project aims to replace the currently used anti-aircraft systems — now nearing the end of their operational life — and to fill a significant gap in the ability to counter stand-off weapons, i.e., weapon systems launched from a long distance.

The new system will allow expanding airspace coverage at medium range, complementing the long-range Patriot system already in use. Existing systems, such as Stinger and medium anti-aircraft artillery, are no longer adequate to counter modern threats, such as missiles and aircraft capable of striking from high altitude and long distance.

International spread and future development

Besides Switzerland, the IRIS-T SLM system is already in use in Germany and Ukraine. Latvia formalized an order in November 2023, while Slovenia and Bulgaria joined the program during 2024. Each system is composed of a TRML-4D radar, a command center for fire control, and multiple mobile launchers.

In parallel, Diehl signed a cooperation agreement with the Danish company MDSI to extend the integration of the short-range IRIS-T missile on a wider range of combat aircraft. Currently, the missile is already integrated on Eurofighter, Gripen, F-16, Tornado, EF-18, KF-21, and F-5E.

“Thanks to the partnership with MDSI, we are expanding the deployment possibilities of our missile system even on platforms previously considered of limited compatibility,” stated Martin Walzer, senior manager for Diehl's integration programs.

Sources:

• https://www.ar.admin.ch/en/nsb?id=105630
• https://www.admin.ch/gov/en/start/documentation/media-releases.msg-id-102847.html
• https://www.diehl.com/defence/en/press-and-media/news/diehl-defence-enhances-integration-capabilities-of-iris-t-missile-into-fighter-aircraft-platforms/