Lockheed Martin Rolls Out Crowsnest Solution.

Lockheed Martin UK Integrated Systems (UKIS) has revealed details of its bid for the UK Royal Navy's (RN's) Crowsnest airborne surveillance and control (ASaC) programme, claiming that its proposed radar/mission system offers a 'future-proofed' solution exploiting the capability of IAI Elta's EL/M-2052 active electronically scanned array (AESA) multimode radar.

Lockheed Martin Rolls Out Crowsnest Solution.

Intended to replace the RN's current Sea King ASaC.7 (SKASaC) from 2018, the Crowsnest programme is based on the provision of a roll-on/roll-off mission fit for the 30 RN Merlin HM.2 anti-submarine warfare (ASW) helicopters currently being delivered under the Merlin Capability Sustainment Programme (MCSP). Current planning assumptions call for the acquisition of 10 Crowsnest kits; a Main Gate investment decision is planned for April 2016.

Lockheed Martin UK, prime contractor for the Merlin HM.2 upgrade, in 2013 received a GBP24 million (USD36.3 million) Assessment Phase 3 (AP3) contract from the Ministry of Defence (MoD) to manage a competition between Thales UK and the separate 'firewalled' Lockheed Martin UKIS mission system team for the design, development, and demonstration of the Crowsnest radar and mission system solution.

AP3 activities are intended to mature the capability requirement, system requirements, system design, and subsequent programme for demonstration and manufacture and in-service support. Thales and Lockheed Martin each received AP3 technology demonstration contracts in late 2013; the rival proposals were submitted at the end of January 2015, with a downselection to a single solution expected during the second quarter of this year.

The Lockheed Martin UKIS Crowsnest mission system team is bidding a solution that marries the HM.2 mission system introduced under the MCSP with two integrated sensor pods installed on weapon carriers port and starboard. Each pod hosts AESA radar arrays, an associated electronically scanned Identification Friend or Foe interrogator (IFFi), and an environmental control system.

The EL/M-2052 radar configuration advanced for Crowsnest incorporates dual fixed-face arrays in each sensor pod so as to confer full uninterrupted 360-degree radar coverage. According to Younus Mustafa, capture manager for Lockheed Martin UK's Crowsnest mission system bid, the EL/M-2052 was selected "for the maturity of the technology, while at the same time providing a solution that is 'future-proofed' to enable growth and upgrades for next-generation threats.

"Compared to a mechanically scanned radar, AESA technology means less track breaks [and] greater consistency and coherency in the radar picture," he added.

The sensor pod concept has been proved through a series of flight trials using a Boeing 737 testbed (using a dual array mounted in the nose), and subsequently a Merlin HM.2 helicopter (with dual arrays fitted port and starboard in pre-production standard pods). "The arrays flown on the 737 [January 2014] and Merlin [July to November 2014] were both populated with 320 TRMs [transmit/receive modules]," 

Mustafa said. "As well as proving array integration, radar performance, and air vehicle impacts we were able to demonstrate the necessary cooling performance. That is a big issue for AESA arrays."

In January this year, a fully scaled (1,024 TRM) array was subject to power aperture measurement, thermal testing, and beamforming characterisation. According to Lockheed Martin, these trials provided objective evidence to support the company's radar and thermal performance claims.

Lockheed Martin has elected to re-use the Thales France combined IFF interrogator/transponder system currently in service on the SKASaC given that it is relatively new to service. However, it will introduce a new electronically scanned IFFi antenna, to be fitted above the dual radar arrays in each pod.

Inside the rear cabin, Lockheed Martin is proposing a series of ASaC-specific mission system embodiments designed to improve picture compilation and reduce operator workload. These include an expanded tactical display, the addition of a secondary tactical display unit, new display formats, 

Automatic track management operator decision aids, and the introduction of a sensor correlation engine (based on that already in service on the US Navy's MH-60R helicopter). The ASaC software load will reside in the system alongside the standard ASW software baseline.

Physical role change time is put at no more than three hours. "Installation of the sensor pods on the weapon carriers will take about 15 to 20 minutes," said Mustafa. "Inside the cabin, sonics equipment and sonobouy stowage will be removed, two role-fit equipment racks installed on existing seat rails, and a system interface panel installed on the existing console.

"There is no more than 100 kg [additional] weight between the ASW and Crowsnest fits, so there is very little difference in on-station time."

Other companies listed within Lockheed Martin's Crowsnest team include BAE Systems (supplying its Cayman tactical datalink product) and Vector Aerospace (selected to manufacture the composite sensor pods).