Unitary Plan Wind Tunnel, Wind tunnel research facility at NASA Ames Research Center, Mountain View, US.

The Unitary Plan Wind Tunnel is a research facility at NASA Ames Research Center in Mountain View with three separate test sections. It can reach flow speeds ranging from subsonic Mach 0.2 to supersonic Mach 3.5 conditions.

The facility opened in 1955 to advance American aviation technology following concerns about international competition during World War II. It was developed as part of a national strategy to secure technical leadership in aeronautics.

The name comes from the 1949 Unitary Plan Act, which coordinated wind tunnel construction across NACA, the Air Force, industry and universities. The complex was declared a National Historic Landmark in 1985. Visitors to the site can see the blue circular emblem on the white cylinder, arched with the words "UNITARY PLAN" and "WIND TUNNELS".

The complex sits within NASA Ames Research Center at Moffett Federal Airfield, an active federal site with restricted access; the tunnels are working research equipment, not a museum. The three test sections share one drive system, so only one section runs at a time. The 8-by 7-foot supersonic section was decommissioned in the early 1990s and is mothballed.

Four electric motors drive the wind systems and generate roughly 260,000 horsepower through independent test chambers. This tremendous power output allows the facility to achieve extremely high speeds in the test sections.