Crowsnest – the strike carrier’s eye in the sky

Crowsnest is the name for the project to provide a new airborne early warning system for the RN. Sea King Mk 7 helicopters operated by 849 Naval Air Squadron currently operate in this role and provide what is now called Airborne Surveillance and Control (ASaC). They are the last Sea Kings remaining active in UK service but are due to go in 2018, by which time this type will have served for nearly 50 years.

The common sense solution

Crowsnest will not involve the purchase of any new aircraft. Instead, the RN will receive 10 equipment kits for fitting to some of its 30 Merlin HM2s. The £269M contract for these kits was finally placed in January (including £9M worth of spares). Development of the system has been underway for some time and flying trials have started using a Merlin HM1 test aircraft. The project will provide work for more than 200 people in the UK; Lockheed Martin (Havant), Thales (Crawley) and Leonardo Helicopters (Yeovil).

The Crowsnest system is an evolution of the well proven Cerberus tactical sensor suite and the Searchwater 2000 radar that currently equips the Sea King Mk7s. The radar is mounted in an inflatable bag on the port side of the helicopter and can be raised by rotating through 90º for landing. The Crowsnest system will employ a slightly adapted mounting but will work in a similar way. The Cerberus system has been successfully evolved over many years and is able to monitor up to 600 contacts simultaneously. The Searchwater radar is able to ‘look down’ and track small, fast-moving targets over land and water or ‘look up’ and track multiple aircraft. The “baggers” as the ASaC helicopters are affectionately called, proved their worth in Afghanistan, clocking up 3,000 flying hours and over 800 missions providing over-watch for NATO forces on the ground. At sea they have successfully provided reassurance for the RN and its allies in multiple operations since 1982.

The exact details of the range and capabilities of the new system are obviously not in the public domain but it will feature an improved human interface, better target identification and hardening against electronic jamming. The MoD has selected a very low-risk and affordable solution, building upon existing technology and fitting it on an aircraft that is already in service that will not need a new logistics or training pipeline.

In the current fiscal climate, Merlin/Cerberus was the only realistic option. Lockheed Martin had proposed a more sophisticated Merlin-based option using a podded AESA radar, derived from the F-35 but it was obviously more expensive. Many would have liked to have seen a V-22 Osprey based ASaC solution (tilt-rotor aircraft). This potentially offers better range and surveillance coverage than a helicopter. Unfortunately, this only exists on paper as a concept and would have added more time and cost to develop, as well as adding an aircraft to the inventory the UK does not (yet) possess.

The correct choice has probably been made but before the order was placed, the MoD had spent more than 17 years and around £40 Million on the Crowsnest project in an excessively drawn out “assessment phase”. In stark contrast to this lumbering process, the original helicopter-borne AEW concept was developed on a shoestring in a just 11 weeks and rushed into service in the wake of Falklands War.

In service, in time, mind the gap

The first Crowsnest kit is due to be delivered in October 2018 and fitted to an operational aircraft by June 2019. Initial Operating capability for the ASaC Merlins will be in 2020, although this is likely to consist of just 2 or 3 aircraft. Effectively there will be an approximately 18-month ‘capability gap’ where the RN has no operational AEW capability between 2018 and 2020.

824 Naval Air Squadron provides training for ASW Merlin aircrew and will also take on responsibility for ASaC training. Some 849 NAS personnel have already begun to convert from the Sea King to the Merlin, ready to take over the new Crowsnest aircraft when they begin deliveries next year. Full Operating Capability for Crowsnest (Ideally at least 6 aircraft and trained aircrew) should be achieved in early 2022, slightly ahead of the FOC for HMS Queen Elizabeth in the Carrier Strike role in 2023.

Kits not aircraft

With just 30 Merlin HM2 airframes available to the RN, it is unfortunate that the Crowsnest aircraft will have to be drawn from this fleet. To add to the pressures and delays, each HM2 will have to be withdrawn from service while Leonardo spends around 15 weeks adding wiring and mountings for the Crowsnest kit. Fitting out all 30 aircraft will have to be spread over several years.

Theoretically, the Crowsnest kit can then be installed in any Merlin in a process that should take around 24 hours, either ashore at RNAS Culdrose or in the spacious hangar of the QE class aircraft carriers. A Merlin changing from the anti-submarine role to ASaC will have its dipping sonar, sonobuoy carousel and ASW consoles removed before the ASaC equipment is added. It is expected that between 6 and 8 Merlins will have the ASaC kit fitted at any one time, with spares available at sea should an ASaC Merlin become unserviceable or lost. This appears to offer some useful flexibility as the carriers will need continuous ASaC capability most of the time. Unfortunately switching precious ASaC platforms to ASW (or vice versa) is far from ideal. The Merlin may have lower maintenance requirements than the Sea King, but 13 aircraft are being replaced by 6-8 kits fitted to aircraft in the existing fleet, a further significant and unwelcome fall in the total number of available airframes.

Crowsnest will be a small upgrade in capability but having proved very useful in non-maritime environments, RAF ISTAR assets are stretched and we need to properly protect our aircraft carriers, there is a very strong case for expanding the number of aircraft, not of reducing them. The obvious solution is to utilise the 10 ‘spare’ Merlin HM1 airframes that have been mothballed for some time, even if not upgraded to HM2 standard. Even the modest funds to refurbish these aircraft do not seem to be available and the RN is again put in a position where it must rob Peter to pay Paul.