Sea King Mk7 ASaC

The Sea King Mk7 Airborne Surveillance and Control – known throughout the Navy as Baggers – are the ‘eyes in the sky’ of the Navy, searching for aerial threats to the Fleet – or suspicious movements on the ground in support of land forces. The nickname comes from the distinctive inflatable black sack or bag on the side of each helicopter. Inside that sack is the cutting-edge Searchwater 2000 radar capable of remarkably accurate detection of surface and air targets. Once enemy units are detected, the helicopter’s observers can direct friendly air, sea or ground forces to intercept – as they did with devastating effect during the fighting in southern Iraq in 2003. It was deployed in Afghanistan from 2009 to July 2014 flying more than 9,000 hours over 2,000 sorties to support troops on the ground.

849 Naval Air Squadron is the parent unit of the Airborne Surveillance and Control family based at RNAS Culdrose in Cornwall providing the two front line squadrons, 854NAS and 857NAS with trained pilots, observers and ground crew ready for front-line operations around the world.

854 and 857 Naval Air Squadrons deploy with carrier task groups  keeping track of aerial activity and keeping tabs on movements on the ocean.

As part of the restructuring in preparation for transition to Merlin Mk2 helicopters, in early 2015, 854 and 857 will disband and 849 NAS will be rededicated as a frontline squadron with three flights.

The Ministry of Defence has disclosed plans to run on a limited number of Sea King ASaC.7 helicopters to 2018, beyond the March 2016 out-of-service date previously set for the Sea King fleet, closing the gap between the retirement of the ASaC.7 and the introduction of the Crowsnest role-fit for the AgustaWestland AW101 Merlin HM.2.

The Ministry of Defence has specified that the Crows Nest system of radar and consoles be capable of rapid mounting on, and removal from, the Navy’s 30-strong fleet of Merlin HM.2 helicopters. The Merlin MK1s are currently being upgraded by Lockheed Martin UK. Thales UK provides the ASaC system on the soon-to-be-retired Sea Kings. Both Thales and LMUK are in the running to gain the contract. The MoD’s Crows Nest procurement team has told LMUK and Thales to expect a decision in 2015 so that the system can be in service beginning in 2018.

The Thales solution for the Crows Nest AEW requirement includes a radar housing that slides down a rack fitted to the mid-fuselage of a Merlin helicopter, to provide 360-degree coverage. The radar would be based on an upgraded version of the radar currently used on the Sea King.

In Lockheed's solution, the radar is contained in a pod and is planned to be fitted to existing hard points on the Merlin helicopter. The Vigilance pod also contains the processor and power system, an IFF interrogator, GPS/INS, ESM sensors and its own cooling system. Two of these pods, mounted on the torpedo hardpoints of the Merlin HM2, can give 360° degrees of AEW and land surveillance capability. They only need a single power source connection, and can work with the software and tactical workstations of the Merlin HM2.