CSG25 sails with the benefit of fully operational Crowsnest ASaC capability
Peter Felstead
The UK Royal Navy’s Carrier Strike Group 25 (CSG25), which departed for its eight-month Operation ‘Highmast’ deployment on 22 April 2025, is benefitting from the Crowsnest Airborne Surveillance and Control (ASaC) programme reaching full operating capability at the end of March 2025.
Of the nine Royal Navy Merlin HM2 helicopters deployed to be the eyes and ears of the UK Carrier Strike Group, three are fitted for the ASaC mission.
Just prior to the carrier strike group’s departure, the nine Merlin HM2s, from 820 Naval Air Squadron, arrived on the aircraft carrier HMS Prince of Wales from their home base at Royal Naval Air Station (RNAS) Culdrose.
The overall Merlin Helicopter Force operating with the carrier strike group, numbering 200 personnel, will provide what the UK Ministry of Defence described as “cutting edge” anti-submarine warfare and airborne surveillance and control capabilities for the task group. Wherever CSG25 operates, the Merlins will hunt threats beneath the waves, scan the horizon for air and surface threats and can be used to co-ordinate defence and strike operations.
“The principal reason for having the ASaC capability and the Crowsnest programme to do that is for protection of the strike group against air threats and, although it doesn’t fire anything to engage missiles, it’s there to provide early warning to ships and particularly for the threats that ships would struggle to see themselves,” explained Captain Colin McGannity, Carrier Air Wing and Strike Warfare Commander for CSG25. “By getting a really capable radar up high and looking down, we’re taking advantage of all the lessons that we’ve learned in the past, particularly back in the Falklands War to make sure that we’ve got that capability to help protect the strike group.
“Now the capability is right where we need it to be,” Capt McGannity added.
Lockheed Martin was awarded a GBP 269 million (EUR 315 million) contract to deliver the Royal Navy’s Crowsnest ASaC programme in 2017.
As well as integrating an updated version of the Thales Searchwater radar and the Cerberus mission system, the programme involved installing a new datalink to share live tactical information with the ships below. The programme also included working out the logistics of maintaining a fleet of ASaC helicopters at sea and installing a new simulator at RNAS Culdrose to prepare a cadre of experienced aircrew of observers and pilots to run the system.
During its eight-month deployment CSG25 will conduct a series of exercises and operations with air, sea and land forces of a dozen allies in the Mediterranean, Middle East, South-east Asia, Japan and Australia.
