Northrop Grumman is to offer a variant of its RQ-4 Block 20 Global Hawk for the US Navy's Broad Area Maritime Surveillance (BAMS) unmanned air vehicle programme.
Lockheed Martin has already teamed with General Atomics to propose a derivative of the latter company's Predator B, known as Mariner, but earlier this year said it could also offer a development of its Polecat demonstrator if the requirement calls for a stealthy high-altitude UAV (Flight International, 25-31 July).
A formal request for proposals (RFP) is expected in May or June next year, and could also draw bids from contractors including General Dynamics, which has previously talked of offering an optionally manned version of the Gulfstream G550 business jet.
An under-$1 billion development contract is expected to be awarded in September 2007, leading to initial operational capability in 2011 with sufficient vehicles to maintain one continuous orbit.
Rather than specify the number of UAVs per system, a draft RFP sets an "effective time on station" requirement to maintain 24h coverage at 3,700km (2,000nm) range for seven days, with 85% availability. This "persistence at range" requirement will drive the number of vehicles, and is a key aspect of the competition.
Full operational capability will provide five orbits, one for each deployed US Navy fleet, with the UAVs operating alongside the USN's manned Boeing P-8A Poseidon multi-mission maritime aircraft.
Northrop has demonstrated the Global Hawk's ability to identify ships with a maritime-adapted version of the current sensor payload, but a more advanced radar is planned for the BAMS offering. The company has also conducted analyses to ensure that the high-altitude UAV's structure can withstand repeated descents to lower altitude, under the weather, to image ships using its electro-optical/infrared sensor before climbing back to cruise altitude.
The USN, meanwhile, hopes to have initial international cooperation agreements for BAMS in place by early next year.
Negotiations are under way with several countries including Australia, which in July announced plans to join the programme to meet its endurance UAV requirements.
The USN tried a similar approach with its P-8A programme, targeting Australia, Canada and Italy, but failed to secure agreements for participation in the platform's development.