Northrup Grumman to Fly Surveillance

By Graham Warwick

Washington

Airships are survivors—a genus of aircraft that has been around since the dawn of aviation and is now being offered another chance at lasting success. This time the mission is persistent surveillance, but can undisputed endurance carve out a role for unmanned airships that lasts beyond today’s war?

As it embarks on a $517-million contract to develop the Long-Endurance Multi-intelligence Vehicle (LEMV) for deployment by the U.S. Army to Afghanistan in early 2012, Northrop Grumman believes the unmanned airship can find long-term roles in border security and disaster relief, as a communications and surveillance platform. “There is a lot of emphasis on today’s war, but tomorrow the airship can provide inexpensive surveillance,” says Alan Metzger, Northrop Grumman LEMV program director.

The vehicle will use 15,000-20,000 lb. of fuel to stay aloft for 3-4 weeks in the surveillance role. “That’s only $20,000-25,000,” he says. The Army calculates it would take 12 MQ-9 Reaper-class fixed-wing unmanned aircraft and their crews to sustain the same mission.

The LEMV’s role is to maintain continuous surveillance over a wide area, providing correlated video, radar and signals intelligence data to the brigade combat team on the ground. Stripped of its sensors and long-endurance fuel tanks, the same vehicle could lift 20 tons of cargo with minimal modification, says Metzger, adding: “Airships are not for everything, but there are opportunities they are suited for. It will come down to economics.”

Part of Northrop Grumman’s optimism is built on the characteristics of the hybrid airship, a heavier-than-air design that combines buoyant, aerodynamic and propulsive lift to provide extended endurance in a vehicle that is easier to operate than traditional lighter-than-air craft. The efficiency of aerodynamic lift is key to LEMV being able to provide “unblinking eye” surveillance from 20,000 ft. for at least 21 days, carrying a 3,500-lb. payload of sensors.

Northrop Grumman’s partner in the LEMV program is Hybrid Air Vehicles (HAV), custodian of the long legacy of Airship Industries and a pioneer in the development of hybrid airships. HAV is responsible for design of the LEMV air vehicle, and the 300-ft.-long, optionally manned platform, called the Condor 304, is scaled up from the HAV3 unmanned demonstrator the U.K. company has been flying for some time.

The endurance goal would be “difficult to do with a conventional airship,” says Gordon Taylor, HAV’s sales and marketing director. About 60% of the lift is aerostatic, from helium buoyancy, and the remaining 40% is aerodynamic, from the vehicle’s shape. “We take advantage of aerodynamic lift in flight for the sustained capability,” says Kelly Whalen, Northrop Grumman strategy development director. Additionally, powered lift is used during takeoff and landing by vectoring the thrust from four ducted propulsors.

The Army wanted a vehicle that could be delivered within 18 months, so Northrop Grumman looked for a low-risk design and an experienced partner, says Metzger. The companies that preceded HAV developed the Skyship 500 and 600 commercial airships and the Sentinel 1000, a half-scale demonstrator for a U.S. Navy airborne early-warning airship that never materialized. Roger Munk, who formed what became Airship Industries and began development of the hybrid airship, was HAV’s president and technical director until his death in February.

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