The US Army has successfully tested a ground-based sense and avoid system with a General Atomics Sky Warrior at an unmanned aircraft test site in El Mirage, California. The army says this is a hurdle that will help to restore its night unmanned air vehicle operations after a five-year hiatus.

The effort is part of a broader multi-service project to demonstrate both ground and airborne sense and avoid systems for UAVs in a bid to accelerate work to integrate the aircraft into the US national airspace system (NAS), which is controlled by the Federal Aviation Administration. The US Air Force plans to test an airborne system later this year.

Sky Warrior 1 
 General Atomics Sky Warrior

Key for the army, which is the lead for the ground-based sense and avoid system, is to provide active and reserve units with the ability to more easily run training missions for aircraft systems and payload operations, which today have to be carried out in restricted military airspace or with certificates of authorisation granted by the FAA.

"We've got aircraft in the thousands flying in the theatre," says Col Gregory Gonzalez, programme manager for army unmanned aircraft systems. "When units come back, they have to train with those systems in very limited airspace across the country."

Further crimping readiness, the FAA in 2005 began requiring the military to use chase aircraft for night operations due to safety concerns related to an increasing number of UAV operations.

During tests in the third week of January, Gonzalez says the army "demonstrated to some degree" to the FAA that by using two linked ground-based radar systems, observers could "get our [Sky Warrior] to the ground quickly, land it and get it out of the way" if a manned "intruder aircraft" entered the flight-test area.

"Now we have to finalise the safety case for the FAA in order to get some authorisation for night flight without a chase aircraft," he says. "This is the first time I can say I'm confident that this year we will have some inroads into the NAS in terms of training."

Source: Flight International