The Firebrand is one of the first combat aircraft designed as a flying wing (with a vertical aileron but no tail assembly). Instead, the aircraft maneuvers using flaps on the leading and trailing wing edges. With such a large wing area, the Firebrand can attain altitudes of up to 35,000 feet, and carries a formidable weapon payload. The trade-off for these capabilities is a reduction in agility, speed and acceleration. Still, the Firebrand can reach 250 m.p.h. in level flight, propelled by twin Wright Tornado G500 engines and pusher propellers.

Designed as a two-man craft, the cockpit affords an excellent all-round view and is equipped with dual controls (allowing either crew member to pilot the aircraft). This feature is particularly valuable on long flights, as it allows the pilot and co-pilot/bombardier to share their responsibilities. The Firebrand has an operational range of 800 miles, provided its speed does not exceed 180 m.p.h.

The Firebrand carries four cannons (two .50- and two .70-caliber), usually backed by rockets and bombs. Armor-piercing rockets are the most common under-wing payload, but many crews choose to carry non-lethal rockets (such as sonic or flare munitions); any additional means of distracting an enemy aircraft is vital to the ungainly Firebrand, considerably enhancing its chances of defeating enemy craft and escaping.