 During their development, these aircraft were tested at NASA Ames Research Center's full-scale aerodynamic complex in Mountain View, California, the largest wind tunnel in the world. The newly renovated facility actually houses two test sections that can accommodate just about any full-scale airplane. The first, which measures 40 by 80 feet, is used to test most of the nation's important aircraft since 1944. It even played a major role in testing the aerodynamic qualities of the spectrum. The second wind tunnel test section measures 80 by 120 feet. In every way, this test section is large. The air intake side of the building is larger than a football field. There are tremendous turning veins in the shaft of the wind tunnel designed to straighten air flow. They are 12 stories high and 160 feet wide. Both wind tunnels are powered by the same bank of six electric 22,500 horsepower motors that were upgraded to provide a maximum airspeed of 345 miles per hour in the 40 by 80 foot test section and 115 miles per hour in the larger tunnel. These giant drive fans are so huge that it takes four persons to rotate one set of blades during an inspection. Before any aircraft can be tested in the 80 by 120 foot tunnel, a special calibration boom must be installed. The delicate instrumented 90 foot probe determines the quality of the air flow and helps engineers compensate for effects caused by the wind tunnel itself. One of the facility's greatest success stories was during this plane, the XV-15 Tilt Road. The XV-15 is a unique one of helicopter and airplane. NASA's twin prop rotors can effortlessly move the plane in virtually any direction. But in undergone extensive wind tunnel and flight testing, the plane has proven its capabilities as a test bay and is now being adapted for practical applications. NASA's national full-scale aerodynamics complex, the largest wind tunnel in the world, is providing accurate full-scale testing for industry and government.