November 24, 2025
Strategic Partnership Between CNN MCO, Thales, and CS Group for the Modernization of Three French Navy Amphibious Helicopter Carriers Under the Project Management of the Fleet Support Service
As part of the French Navy’s fleet maintenance program (MCO), CNN MCO, a division of Equans France, has announced a strategic partnership with Thales and CS GROUP, a subsidiary of Sopra Steria, to equip amphibious helicopter carriers (PHA) with a new, highly resilient inertial navigation system designed for electronic warfare environments. The three companies are thus forming a 100% French and sovereign industrial consortium dedicated to naval performance.
Following tests that confirmed the performance of the selected solution, an initial deployment has just been successfully completed aboard the Mistral during its technical stop at the Toulon naval base.
The Fleet Support Service (SSF) is leading this initiative to modernize navigation systems on PHA vessels and has commissioned its operational maintenance contractor—CNN MCO—to carry out the work (contract awarded in 2022 for a term of eight years).
This contract, which also includes the operational maintenance (MCO) of the command and replenishment ship (BCR) Somme, covers all onboard equipment of the three PHAs—the Mistral, the Tonnerre, and the Dixmude.
The objective is to ensure the at-sea availability and full operational capability of these platforms in an increasingly demanding strategic environment.
In response to the gradual obsolescence of certain critical equipment, more than 40 modernization studies have been incorporated into the contract. These studies, conducted on three separate vessels, have already resulted in 50 deployments carried out over two years.
CNN MCO oversees these phases, in close coordination with the SSF, from the preliminary design studies through to on-board integration.
Autonomous and Reliable Navigation in the Face of New Threats
Against a backdrop of hybrid conflicts and widespread jamming of radio navigation systems, the French Navy is enhancing the autonomy and resilience of its navigation systems. The TopAxyz inertial navigation systems, developed by Thales, rely on fully controlled internal data, independent of any external source.
Using onboard sensors (accelerometers and gyroscopes), they measure the ship’s movements to continuously calculate its position, speed, and heading, without relying on external signals such as GPS.
Built on more than 40 years of experience, they have accumulated over 50 million hours of operational use in a variety of applications: space, civil and military aviation, and land-based systems. By equipping its PHA vessels with this technology, combined with capabilities to detect decoy and jamming attempts, the Navy is enhancing its ability to navigate with precision, discretion, and reliability, even in the most sensitive areas.
A Custom Navigation System
Within the consortium, CS GROUP contributes its cutting-edge expertise in navigation systems. Thales’ inertial navigation systems will be integrated into CS Group’s overall navigation system. Since the navigation system serves as the backbone of a warship, ensuring precise positioning and safe maneuvering, this technological partnership guarantees accuracy, resilience, and service continuity in the most demanding maritime environments.
With more than 15 years of experience, CS GROUP specializes in the integration of all navigation sensors, the development of resilient and cybersecurity-protected navigation data distribution systems, and the mass production of ruggedized onboard systems for harsh environments. The integration of this new equipment, carried out by CNN MCO, is performed in compliance with safety requirements and within existing infrastructure.
To date, the retrofit studies have required nearly 1,500 engineering hours from CNN MCO’s in-house design office, in partnership with Thales and CS Group
A phased rollout, coordinated with scheduled maintenance
The deployment of these units and associated equipment follows the schedule of scheduled maintenance outages planned by the SSF through 2027. The Mistral will be the first to benefit from the new system, followed by the Dixmude and the Tonnerre. Once the Thales inertial navigation systems have been integrated into the navigation modules by CS GROUP, the systems will be deployed by CNN MCO on the three ships, with a gradual ramp-up aligned with this same timeline.
CNN MCO is responsible for the integration, test supervision, and maintenance of the equipment, working directly with the SSF teams. The goal is to optimize deployment windows to ensure the operational availability of the systems at sea.
“This program confirms CNN MCO’s ability to carry out complex modernization projects in an onboard environment. We are proud to contribute to the modernization of sensitive equipment aboard ships as part of a 100% French initiative alongside the SSF, Thales, and CS GROUP. ” - Céline Barazer, Deputy Director of CNN MCO, a division of Equans France
“Following aircraft, space launch vehicles, air defense systems, and artillery, Thales’s 40 years of expertise in inertial navigation systems are now being applied to Marine Corps operations. We are proud to contribute to the resilient navigation of ships, a prerequisite for the armed forces’ freedom of action at sea. ” Florent Chauvancy, Vice President of Flight Avionics, Thales
“By working alongside CNN MCO and Thales to develop a 100% French solution, we are reaffirming the importance of domestic expertise in support of the French Navy. As a long-standing partner of the naval forces, CS GROUP is proud to put its expertise to work for the performance and safety of the fleet’s vessels, and to ensure the seamless and resilient integration of the entire navigation chain ” - Frédéric Dussart, Director of Defense & Security Activities at CS GROUP
