The French Navy has officially welcomed its first Defense and Intervention Frigate (Frégate de Défense et d’Intervention – FDI), Amiral Ronarc’h (D660), to its homeport in Brest. This marks a pivotal milestone for France’s naval modernization program as the FDI class enters operational integration. Designed by Naval Group and equipped with cutting-edge combat systems from Thales and MBDA, the FDI represents a generational leap from the FREMM-class frigates.
FDI Program Overview: From Concept to Commissioning
The FDI program was launched under France’s 2019–2025 military programming law (LPM) to provide a new generation of compact yet powerful surface combatants capable of operating across high-intensity environments. The class is also known as the Belharra-class for export markets.
Naval Group was awarded the contract for five FDIs in April 2017 by the French Direction Générale de l’Armement (DGA). The lead ship Amiral Ronarc’h was laid down in 2020 and launched in November 2022 at Lorient. Following sea trials conducted throughout 2023 and early 2024—including live-fire testing of its Aster missiles—the vessel was formally delivered to the French Navy on July 4, 2024.
Amiral Ronarc’h is expected to achieve full operational capability (FOC) by late 2025 after completing crew training and integration into the Atlantic fleet based at Brest. The remaining four ships—Admiral Louzeau, Admiral Castex, Admiral Nomy, and Admiral Cabanier—are scheduled for delivery between 2025 and 2030.
Design Philosophy: Compact Yet Heavily Armed
The FDI design reflects a shift toward more compact but highly capable platforms optimized for both blue-water operations and littoral engagements. At approximately 4,500 tonnes displacement and measuring around 122 meters in length, these frigates are smaller than their FREMM predecessors but pack comparable firepower.
Key design features include:
- Stealth shaping: Reduced radar cross-section through faceted surfaces and enclosed masts
- Integrated mast: “Panoramic Sensors & Intelligence Module” (PSIM) housing radar arrays and EW sensors
- Crew complement: Around 125 personnel with accommodation for up to 150
- Modular mission bays: For RHIBs or unmanned systems
- Aviation facilities: Hangar and flight deck support NH90 or similar medium helicopters
Sensors & Combat Systems: Sea Fire AESA Radar at Core
The centerpiece of the FDI’s sensor suite is Thales’ Sea Fire radar—a fully digital Active Electronically Scanned Array (AESA) system operating in S-band. It provides simultaneous air/surface surveillance with multi-target tracking capabilities essential for modern air defense missions.
The Sea Fire enables early detection of low-RCS threats such as stealth aircraft or sea-skimming missiles. It also supports guidance updates for Aster family interceptors via datalink.
The ship integrates a comprehensive combat system architecture featuring:
- Sylver A50 VLS cells: Hosting up to 16 MBDA Aster-15/30 SAMs
- NARWHAL remote weapon stations: For close-in defense
- Mk41-compatible strike capabilities: Not currently installed on French variants but available for exports like Greece’s configuration with SCALP Naval cruise missiles
- CANTO decoy launchers: Anti-torpedo countermeasures developed by Naval Group
- EWS suite: SENTINEL electronic warfare system with RESM/CESM functions integrated into PSIM mast
A Strategic Asset for NATO Interoperability & Indo-Pacific Posture
The arrival of Amiral Ronarc’h strengthens France’s ability to project power within NATO task groups as well as independently in contested maritime zones such as the Eastern Mediterranean or Indo-Pacific sea lanes. With Link-22 compatibility alongside legacy Link-11/16 protocols, FDIs are fully interoperable with allied navies including those of the U.S., UK, Germany, Italy, and Greece.
This aligns with France’s strategic goal of maintaining a credible presence from Djibouti to New Caledonia under its “strategic autonomy” doctrine while contributing meaningfully to EU-NATO maritime security frameworks.
Brest Integration & Future Outlook
Brest Naval Base will serve as homeport not only for Amiral Ronarc’h but also likely future Atlantic-assigned FDIs. The base has undergone infrastructure upgrades including pier-side power systems compatible with next-gen warships’ energy demands.
The second FDI frigate—Admiral Louzeau—is already undergoing outfitting at Lorient with delivery expected mid-2025. Meanwhile export variants are progressing rapidly; Greece signed an agreement in March 2022 for three FDIs plus one optional unit under a €3 billion deal including SCALP cruise missile capability—underscoring growing international interest in this platform class.
A Modular Backbone for Future Upgrades
The modularity embedded into the FDI design allows future insertion of emerging technologies such as directed energy weapons or AI-enabled decision aids without major structural overhauls. The digital combat management system can be software-upgraded remotely via secure links—a key enabler of lifecycle cost control.
This positions the class well against evolving threats like hypersonic glide vehicles or drone swarms that demand rapid sensor-to-shooter loops supported by resilient C4ISR architectures.
