Air Force Plant 4, Military aircraft manufacturing facility in Fort Worth, Texas.

Air Force Plant 4 is a government-owned, Lockheed Martin-operated aircraft plant beside Naval Air Station Joint Reserve Base Fort Worth. Its long, flat-roofed building has a light facade with vertical panels and a tall dark window band; a blue canopy reading "LOCKHEED MARTIN" with a star emblem covers glass doors and stone-clad steps. Three gray aircraft models stand nose-up before the facade, beside a wireframe globe sculpture and flagpoles.

The facility began operations in 1942 during World War II to produce bombers for military use. After the war ended, it shifted focus and eventually became known for manufacturing modern fighter jets.

The plant's name comes from its status as a government-owned, contractor-operated Air Force facility, run today by Lockheed Martin Aeronautics. Its roughly 17,000 workers make it one of the largest employers in the Dallas-Fort Worth-Arlington area. The blue entrance canopy carries the Lockheed Martin name and star emblem, and three gray aircraft models stand nose-up before the facade.

The site is not open to the general public without prior authorization. Those interested in learning more can reach out to the facility's communication department for inquiries.

The F-35 production line at Plant 4 runs almost 1,600 metres, and preparing for stealth manufacturing made the plant heavily robotic, which the Polish source calls the most modern aircraft factory in the world. Before F-16 output moved to Greenville, South Carolina, 3,620 Fighting Falcons had been built in Fort Worth.