Northrop Grumman unveiled the Scaled Composites Model 437 on Sept. 8 as a low-cost unmanned aircraft system (UAS) derived from the company’s four-year-old, manned Model 401 demonstrator.

The Model 437, which remains a paper concept, gives Northrop a candidate design as the U.S. and allied militaries develop requirements for a new class of autonomous UAS configured to be attritable.

The term attritable—meaning affordable enough to lose on any given mission, yet intended to be reused at least dozens of times—has been linked to several emerging programs, such as the U.S. Air Force’s Skyborg family and the Royal Air Force’s Project Mosquito.

As such, the Model 437, and a proposed unmanned conversion of the Model 401, become Northrop’s answer to an increasingly popular niche, which already includes the Boeing Airpower Teaming System, Blue Force Technologies’ REDMedium, General Atomics-Aeronautical Systems’ MQ-20 Avenger ER, and the Kratos XQ-58 Valkyrie.

Unit costs generally vary with volume, but the concept unveiled by Northrop could enter the attritable market with a $5-6 million price tag, says Cory Bird, vice president of Northrop-owned Scaled Composites.

The price tag is split roughly evenly between Northrop’s airframe and a $2.4 million Williams FJ44 turbofan engine, Bird says. Any mission systems or munitions would come with additional cost. The aircraft is designed to carry two Raytheon AIM-120 Amraam missiles internally or a side-looking radar, he says.

With a 4,000-lb. fuel capacity, the Model 437 can fly missions up to 3,000 nm while cruising at Mach 0.8, Bird says.

The Air Force’s seminal Low Cost Attritable Aircraft Platform Sharing (LCAAPS) program—which helped support development of the Model 401—prized modular designs, with key features that could be rapidly reconfigured depending on the mission. Accordingly, the Model 437 concept includes the option of a longer wing, offering greater endurance at the expense of speed.