Defence

Proposals for the US Navy's Broad Area Maritime Surveillance unmanned air system will be submitted at the end of this month, and Lockheed Martin plans to "push the speed" on its Mariner derivative of the General Atomics Predator B turboprop UAV to compete with the Northrop Grumman RQ-4 Global Hawk and Boeing's offering, which is expected to be an optionally manned version of the Gulfstream G550 business jet.

The US Navy has set an "effective time on station" requirement of 80% at 3,600km (2,000nm) - over seven days as a threshold and 30 days as an objective - "using three or fewer air vehicles per system": one in orbit, one in transit and one on standby. This puts an emphasis on transit speed, as well as endurance and reliability on station. The US Navy has a requirement to maintain five orbits from main or forward operating bases worldwide.

With proposals to be submitted on 30 April, Lockheed is not providing bid details, but will "push the speed" on the turboprop UAV to compete with the faster jets, says senior manager BAMS business development Chuck Martello. An artist's impression of the vehicle shows a Predator derivative with increased wingspan and an extended inboard leading-edge that increases sweep and area.

The BAMS vehicle will carry a maritime radar with synthetic-aperture, inverse synthetic-aperture radar and weather modes, and an electro-optical/infrared sensor and electronic support measures for target identification. Martello says a key requirement is "altitude agility" - the ability to descend quickly below the marine cloud layer to identify ships optically then return to surveillance altitude.