The primary aerodynamic testing facility is the F. K. Kirsten Wind Tunnel. Opened for testing in 1939, the Kirsten Wind Tunnel is of concrete construction, with seismic-reinforced brick facade. It is a double-return, closed circuit wind tunnel. The test section has a rectangular cross-section eight feet high, twelve feet wide and ten feet long, with fillets in the corners. The test section is vented to the atmosphere at its downwind end and can be viewed from all sides. Two 500-hp dc motors drive two 14 feet 9 inches diameter, seven-blade fans to provide the test section with airspeed range of about 5 to 200 mph. This provides a dynamic pressure setting range of nearly 0q to 100q for studies on typically sized wind tunnel airplane models. The tunnel is capable of airspeeds of 200 MPH with a clean test section. See Figure 1 .