Developed in two subvariants, Redhead and Roadrunner, it was used by the United States Army in the 1960s and 1970s.

Given the company designation NA-273, the Redhead/Roadrunner drone program produced a small aircraft of largely conventional design, with small delta wings and a downswept tailplane; the vertical stabilizer doubled as a pylon for the aircraft's ramjet engine.

[1] Two minor variants of the drone were produced; 'Redhead' was optimized for high-altitude flight, at heights of up to 60,000 feet (18,000 m), while 'Roadrunner' was a variant for low-altitude operation as low as 300 feet (91 m) above the ground, and both could reach speeds of between Mach 0.9 and Mach 2.

At the end of a flight, if the target drone had not been shot down, recovery could be either on command from the ground station, or automatic in case of fuel exhaustion or loss of control; a retrorocket would decelerate the drone to allow for deployment of a recovery parachute.

The MQM-42 was used primarily to provide training in tracking and engaging targets for the MIM-23 Hawk surface-to-air missile;[3] it remained in service with the United States Army through the mid-1970s.