French Navy Upgrades Navigation on Amphibious Helicopter Carriers

A French industrial consortium has started replacing the navigation systems on three amphibious helicopter carriers as the Navy moves to secure operations against jamming and electronic threats.

The Fleet Support Service (SSF) is directing the work, with CNN MCO, Thales and CS Group delivering the upgrade under an eight-year contract awarded to CNN MCO in 2022.

The program covers the Mistral, Tonnerre and Dixmude, as well as support for the supply ship Somme. It responds to the obsolescence of critical equipment. More than 40 modernization studies are included, and 50 deployments have already been completed across the three vessels. CNN MCO is leading engineering, integration and onboard installation with SSF oversight.

The first installation of the new inertial navigation system was completed on the Mistral during a technical stop in Toulon, following tests that validated system performance. The upgrade centers on Thales’ TopAxyz inertial navigation system, which uses onboard accelerometers and gyroscopes to calculate position, speed and heading without external signals. The Navy aims to maintain precise navigation even under radio-navigation jamming or spoofing.

Thales’ system draws on more than 50 million operational hours across space, aviation and ground programs. It will be paired with sensors designed to detect decoy and jamming activity, enabling ships to operate discreetly in contested areas.

CS Group will integrate the Thales system into its navigation architecture. The company brings experience in sensor integration, cyber-secure data distribution and ruggedized embedded systems. CNN MCO is carrying out retrofit work within existing ship infrastructure. The design phase has required nearly 1,500 hours of engineering in partnership with Thales and CS Group.

The rollout is aligned with SSF’s maintenance schedule through 2027. The Mistral leads the sequence, followed by the Dixmude and the Tonnerre. CNN MCO will supervise testing and maintenance to maintain operational availability at sea.