French Navy Modernizes Amphibious Helicopter Carriers with Thales TopAxyz Navigation System

The French Navy has taken a decisive step in strengthening the operational readiness of its amphibious helicopter carriers through a strategic partnership between the national industrial consortium CNN MCO, Thales, and CS GROUP. This alliance, fully rooted in French industry, is designed to reinforce sovereignty and maritime performance at a time when naval forces face increasingly complex strategic environments. The initiative is part of the broader Fleet Support Service modernization program, which aims to ensure that the Navy’s largest amphibious assets remain fully capable and resilient in contested waters.

Photo: Thales

CNN MCO, a subsidiary of Equans France, has been the prime contractor for fleet maintenance since 2022 under an eight‑year contract. Its role is central to the modernization effort, coordinating with Fleet Support Service while overseeing integration, testing, and long‑term sustainment of new systems. The contract covers the three amphibious helicopter carriers Mistral, Tonnerre, and Dixmude, as well as the command and logistics vessel Somme. Together, these ships form the backbone of France’s expeditionary and humanitarian response capabilities, making their availability at sea a matter of national strategic importance.

Since the beginning of the program, more than forty modernization studies have been conducted, resulting in fifty system upgrades across the fleet in just two years. These upgrades reflect a deliberate effort to anticipate evolving threats, particularly in the domain of electronic warfare and hybrid conflict. The modernization is not limited to incremental improvements but represents a comprehensive overhaul of navigation systems, ensuring that French vessels can operate independently of vulnerable external signals.

At the heart of the modernization lies Thales’s TopAxyz inertial navigation system, a technology that allows ships to determine their position, speed, and heading without reliance on GPS or other external sources. Using advanced accelerometers and gyroscopes, the system continuously calculates navigation data with high precision, even in environments where satellite signals are degraded or denied. This independence is critical in modern naval operations, where adversaries increasingly employ spoofing and jamming techniques to disrupt conventional navigation.

TopAxyz has already accumulated more than fifty million hours of operational use across aerospace, civil aviation, military aviation, and land domains. Its proven track record underscores its reliability and resilience, qualities that are indispensable for naval forces operating in sensitive theaters. By integrating this system, the French Navy ensures that its amphibious carriers can maneuver with confidence, maintaining secrecy and precision even in contested zones. The technology represents a significant leap forward in safeguarding navigation against electronic interference.

Thales provides the TopAxyz units, while CS GROUP, a subsidiary of Sopra Steria, is responsible for integrating them into the ships’ global navigation architecture. CS GROUP’s role includes ensuring secure and resilient distribution of navigation data across the vessel, protecting against cyber threats and guaranteeing operational continuity. CNN MCO, as the lead contractor, manages the integration aboard the ships, supervises trials, and oversees maintenance, coordinating closely with Fleet Support Service to align modernization with operational schedules.

The retrofit process has already demanded nearly 1,500 hours of engineering work from CNN MCO’s internal design teams. This level of effort highlights the complexity of integrating advanced inertial navigation systems into existing ship architectures. Each installation requires meticulous planning to ensure compatibility with legacy systems while minimizing downtime for vessels that must remain ready for deployment. The consortium’s ability to deliver these upgrades reflects the depth of expertise within French industry and its commitment to naval sovereignty.

Implementation is being carried out in phases aligned with scheduled maintenance periods, ensuring that operational availability is not compromised. The Mistral was the first vessel to receive the new system during maintenance at Toulon, marking a milestone in the modernization program. The Dixmude and Tonnerre will follow, with installations scheduled through 2027. This phased approach allows the Navy to maintain a steady tempo of operations while progressively enhancing its fleet’s navigational resilience.

CNN MCO bears responsibility not only for integration but also for optimizing installation schedules to keep ships at sea when required. The company’s role extends to long‑term maintenance, ensuring that the new systems remain reliable throughout their service life. By coordinating closely with Fleet Support Service, CNN MCO ensures that modernization efforts are seamlessly aligned with operational demands, reinforcing the Navy’s ability to project power and provide humanitarian assistance worldwide.

The partnership between CNN MCO, Thales, and CS GROUP represents more than a technical upgrade; it is a statement of industrial sovereignty and strategic foresight. In an era where electronic warfare and hybrid threats are increasingly prevalent, the ability to navigate independently and securely is a decisive advantage. France’s investment in inertial navigation technology ensures that its amphibious helicopter carriers remain at the forefront of maritime capability, ready to operate in contested environments and uphold national interests at sea.

By 2027, the French Navy will field a fleet of amphibious carriers equipped with some of the most advanced navigation systems available, reinforcing their role as critical assets in both military and humanitarian operations. The modernization program underscores the importance of collaboration between industry and defense, demonstrating how national expertise can deliver solutions that enhance sovereignty and operational effectiveness. For France, the integration of TopAxyz into its amphibious fleet is not merely a technological achievement but a strategic imperative, ensuring readiness in the face of evolving global challenges.