Northrop Grumman has proposed meeting the US Navy's effective time on station (ETOS) requirement for a new broad area maritime surveillance (BAMS) fleet with two to three RQ-4N Global Hawks at each of the service's five planned bases.
As one of three bidders for the proposed $2 billion deal, Northrop believes this capability is a competitive advantage because it can meet the navy's performance demand with the smallest number of aircraft.
In the original 2004 competition for BAMS, the USN specified a requirement for five aircraft to be based at each of five locations. But the programme was put on hold until this year, and in the interim the service changed the requirement.
The number of aircraft needed per location is now to be decided by the contractor, as long as the threshold requirement is met to maintain a 3,700km (2,000nm) orbit for seven days with 80% reliability.
Later, the USN hopes to improve that capability to an objective standard for a 30-day surveillance period at 95% reliability.
Bob Wood, Northrop's business development manager for BAMS, claims the company's bid is based on providing two RQ-4Ns to meet the threshold requirement and three to meet the objective.
The aircraft, which is based on the US Air Force's RQ-4B Block 20 Global Hawk, features a 310kt (570km/h) cruise speed and can fly at altitudes above 60,000ft (18,300m).
Northrop is competing for the BAMS award against the Lockheed Martin/General Atomics Mariner medium-altitude unmanned aircraft and the Boeing/Gulfstream G550 business jet.
"An unmanned aircraft that is slower or operating at medium to low altitude and in the effects of wind is not going to be able to get on station," Wood says.
The Global Hawk can fly faster than the Mariner and has a longer endurance than the G550, but is criticised for the BAMS mission for having less agility to change altitudes rapidly.
Wood dismisses such criticism as unfair: "The airplane does not have an endurance hit by descending down low." However, he notes the aircraft will have sensors on board to allow it to perform surveillance and reconnaissance from high altitude.
Wood also reveals that Northrop will offer a new multifunction active sensor radar based on fourth-generation arrays. The RQ-4N would also feature the Sierra Nevada Merlin-MC electronic support measures system.
Northrop also plans to adopt the 900-2 electro-optical/infrared sensor being installed for the USN's Boeing P-8A Poseidon multi-mission maritime aircraft.
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Source: FlightGlobal.com
