A two-seat production derivative of Northrop Grumman’s secretly developed Firebird medium-altitude optionally piloted vehicle (OPV) demonstrator has begun test flights for an unidentified customer.

Flown by two Northrop test pilots, the OPV made its first flight from Mojave, Calif., on Nov. 12. Powered by a single Lycoming TEO-540E piston engine, the twin-boom configured aircraft climbed to 3,880 ft. and reached a maximum speed of 100 kt. during a short, 6-min. circuit.

Some 30% larger than the Firebird demonstrator unveiled in 2011, the production-ready variant is 35.5 ft. in length and has a wingspan of 72.2 ft. The second pilot position was added at the request of the customer, adding a new dimension to the concept of a purpose-designed UAV with the option of an onboard pilot.

The original single-seater version was designed to enable the Firebird to transit through commercial airspace as a conventional aircraft. According to Northrop, the addition of the second seat now gives users the option of a co-pilot and/or sensor systems operator position, while retaining the original goal of providing a low-cost platform for persistent surveillance.

If not being operated in piloted mode, the Firebird UAV is designed to be commanded by a ground station to operate in either line-of-sight (LOS) unmanned mode or beyond-LOS mode. “If you want to go farther [beyond LOS] the canopy comes off, the Garmin [pilot’s avionics] system comes out of the flight panel and an L3 satcom antenna goes in,” says Firebird Program Manager Jerry Madigan.

With a unit cost of $10 million, including avionics and a baseline sensor, the production Firebird is “the perfect replacement for the aging, inefficient and unsustainable fleet of special mission aircraft,” Madigan says. “Some [potential users] are looking at asymmetric warfare situations where aircraft like the [Hawker Beechcraft] King Air or Cessna Caravan do not have the endurance or the versatility,” he adds.

Interest in Firebird grew after the OPV flew at the 2011 Empire Challenge, the final interoperability and intelligence-sharing exercise run before the disbanding of U.S. Joint Forces Command. “At Empire Challenge everybody saw us out there. Before that we kind of kept it quiet,” Madigan says. In all we have flown 12 different payloads, and at Empire Challenge we flew four payloads that we never tested before. These included electro-optic/infrared, radar and a communications relay.”

Although Firebird’s presence at the exercise was sponsored by the U.S. Army, other potentially more immediate customers at the event included U.S. Special Operations Command (Socom). Northrop previously said Socom was interested in Firebird, but Madigan says only that “we competed for an undisclosed customer and we won and they have certain requirements, including a two-seat, production-standard vehicle.”

The initial production contract calls for assembly of two vehicles per year for the next five years.

Images of the Firebird can be viewed at Aviation Week's Ares defense blog.