The UK Royal Navy (RN) has confirmed that its carrier-borne Crowsnest airborne surveillance and control (ASaC) role fit system has reached Full Operating Capability (FOC).
In a 25 April media release, the service said the FOC milestone was achieved at the end of March 2025, just weeks prior to the deployment of Crowsnest-configured Merlin HM2 helicopters with the CSG25 carrier strike group.
Designed to replace the capability previously provided by the Sea King ASaC Mk 7 (SKASaC), Crowsnest is a role-fit for the Merlin HM Mk 2 helicopter that swaps out the standard mission console and sonics suite for an ASaC mission system/radar package derived from that previously fitted to the SKASaC helicopter. Lockheed Martin, as prime contractor, is responsible for integrating the Thales-supplied Crowsnest radar/mission system into the Merlin HM Mk 2; Leonardo Helicopters UK has supported the modification of the HM Mk 2 helicopter fleet to receive the Crowsnest fit.
Crowsnest incorporates updated and repackaged versions of the Thales Searchwater pulse-Doppler radar and Cerberus mission system, including Link 16 functionality. It is primarily designed to provide organic over-the-horizon surveillance against air and surface threats, and airborne tactical command and control in support of the maritime task group.
Lockheed Martin UK was awarded a £269 million Crowsnest demonstration and manufacture contract by the Ministry of Defence in late November 2016. Initial Operating Capability (IOC) was originally scheduled by mid-2020, with FOC planned to follow in early 2022.
However, the Crowsnest programme has run approximately three years late as a result of slippages in software development, and an underestimation of the complexity of integration into the existing Merlin weapon system. A pre-IOC capability delivered for the CSG21 deployment was limited in terms of its functionality and operability. Since then, however, the Crowsnest capability has steadily matured as staged software uplifts have been released, with IOC declared in July 2023.
The software baseline deployed at FOC includes additional radar modes and expanded Link 16 functionality. It also allows for a ‘tactical third operator’ in the Merlin cockpit.
820 Naval Air Squadron (NAS) parents Merlin HM Mk 2 helicopters assigned to the UK Carrier Strike Group. Seven aircraft from 820 NAS – including three in Crowsnest configuration at FOC standard – are currently embarked in HMS Prince of Wales for CSG25 (Operation ‘Highmast’).
Ab initio training for new ASaC observers is being conducted by 824 NAS at Royal Naval Air Station (RNAS) Culdrose. This training pipeline is supported by a Crowsnest-configured rear-crew trainer delivered to the Merlin Training Facility at RNAS Culdrose in 2021. While the Merlin HM Mk 2 helicopter has had its out of service date extended to 2040, the Crowsnest ASaC capability is currently planned to leave RN service at the end of 2029. In early April 2025 the MoD initiated a market engagement activity intended as the precursor for the procurement of a new persistent Carrier Strike Airborne Early Warning capability to succeed Crowsnest. Carrier Strike Airborne Early Warning calls for “the provision and support of an airborne surveillance system that operates from the Queen Elizabeth class aircraft carriers and provides persistent 24 hours surveillance”. While there are no prescribed implementation options, the RN aviation community has previously indicated its preference for an uncrewed carrier-based airborne early warning solution coherent with its broader Maritime Aviation Transformation vision.
