The Defence and Intervention frigates or Fregate de Defense et d’Intervention (FDI) are advanced, high-performance surface vessels designed for the Hellenic Navy (HN).
The frigates have advanced capabilities across all warfare domains including anti-ship, anti-air, anti-submarine and special forces projection. They also feature unique capabilities for countering asymmetric threats.
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The FDI HN programme initially consisted of three frigates, namely the Hellenic ship (HS) Kimon, HS Nearchos, and HS Formion. In November 2024, an order was placed for a fourth frigate under the programme.
The first vessel under the programme, the HS Kimon, was delivered to the HN in December 2025.
The remaining two FDI HN frigates are scheduled for delivery in 2026, while the fourth is scheduled to be delivered in 2028/2029.
FDI HN frigates development details
France-based naval defence company Naval Group and missiles developer MBDA signed a memorandum of understanding in September 2021 to begin negotiations for providing the HN with three FDI frigates and their equipment, along with an option for an additional frigate.
In March 2022, Naval Group signed contracts with Greece to build three FDI HN frigates, with an option for a fourth, including in-service support. The contracts also include the supply of MU90 torpedoes and CANTO countermeasures.
In the same month, MBDA signed a contract to supply air defence missiles and anti-ship missiles for three FDI HN frigates, with an option for a fourth frigate.
FDI HN frigates design and features
The FDI HN frigates have an approximate length of 122m (400ft), a width of 18m and a displacement of 4,500t. The frigate has a maximum speed of 27 knots.
They feature aviation facilities that can accommodate a 10t-class helicopter and a vertical take-off and landing uncrewed aerial vehicle.
Created and built with advanced digital design and production technologies, these frigates are the first in their class to feature an integrated onboard digital architecture. This framework is intended to support continual evolution with technological and operational changes, helping the ships remain effective against rapidly shifting threat profiles.
Furthermore, the underlying architecture and digital infrastructure are designed with long-term expandability in mind, allowing capabilities to be refreshed through phased, incremental enhancements over the ship’s service life, rather than relying on an expensive mid-life modernisation programme.
The vessels are designed with native cybersecurity protection, including two data centres that host nearly all the ship’s software.
The frigates are also engineered and constructed in accordance with Nato requirements, supporting seamless interoperability and secure connectivity with partner navies.
HS Kimon frigate construction details
In October 2022, the first block of the first FDI HN frigate, HS Kimon, was laid down in a dry dock at Naval Group’s shipyard in Lorient. HS Kimon was launched in October 2023, with her panoramic sensor and intelligence module (PSIM) installed in November 2023.
By the end of March 2024, the continuous machinery survey was operational on board, featuring the latest version with several capabilities specific to the HN. The first two Aster 30 vertical launching systems (A50 – Sylver) were installed in early April 2024.
In May 2025, the FDI HS Kimon began sea trials from Naval Group’s site in Lorient, Brittany. The initial phase at sea focused on testing the ship’s platform systems, including propulsion and navigation. A subsequent phase concentrated on combat system trials and assessing endurance at sea.
HS Nearchos frigate construction details
The first pre-outfitted block of the second frigate, HS Nearchos, was moved to the dry dock for keel laying in October 2023.
In April 2024, HS Nearchos’ PSIM was moved to its shore-testing area for a five-month test period, during which many of its systems were activated.
The vessel was launched in September 2024, while her first sea trials commencing in February 2026 at Lorient, France.
HS Formion frigate construction details
The steel cutting for the third frigate, HS Formion, took place in July 2023, while the keel of the frigate’s first block was laid in April 2024. A ceremonial launch was held for HS Formion in June 2025.
The vessel commenced her first sea trials in June 2026 in Lorient, France.
Sensors of FDI HN frigates
The air and surface defences of the frigates are supported by state-of-the-art sensors, including the Thales Sea Fire, the first fully digital multifunction radar with an active antenna and fixed panels.
The FDI HN frigates are equipped with a unique integrated mast that houses all airborne sensors, providing continuous 360-degree surveillance.
Weapons onboard FDI HN frigates
The FDI HN frigates are armed with 32 Aster 30 B1 air defence missiles and eight MM40 Exocet Block 3C anti-ship missiles, both developed by MBDA. The frigates are also equipped with Rolling Airframe Missiles.
Furthermore, the FDI HN frigates are designed with four torpedo tubes to deploy MU90 torpedoes developed by the Naval Group. They also feature a 76mm gun, two decoy launchers and CANTO countermeasures, all developed by Naval Group.
Contractors involved
In December 2025, METLEN, an industrial and energy group, delivered integrated mechanical, hydraulic, electrical and electronic equipment for the second FDI frigate.
