https://www.usa.gov/copyrighted-government-workshttps://www.rawpixel.com/image/441384![Four Engine USB Model in the 40x80 foot Wind Tunnel. Large-Scale Upper-Surface Blowing Model using JT15D Engines. Test #441…](https://images.rawpixel.com/image_social_square/czNmcy1wcml2YXRlL3Jhd3BpeGVsX2ltYWdlcy93ZWJzaXRlX2NvbnRlbnQvbHIvcGQzNi01LWFjNzQtMjc1Nl8xLmpwZw.jpg)
![Four Engine USB Model in the 40x80 foot Wind Tunnel. Large-Scale Upper-Surface Blowing Model using JT15D Engines. Test #441…](https://images.rawpixel.com/image_social_square/czNmcy1wcml2YXRlL3Jhd3BpeGVsX2ltYWdlcy93ZWJzaXRlX2NvbnRlbnQvbHIvcGQzNi01LWFjNzQtMjc1Nl8xLmpwZw.jpg)
Four Engine USB Model in the 40x80 foot Wind Tunnel. Large-Scale Upper-Surface Blowing Model using JT15D Engines. Test #441, June 18th, 1974. Original from NASA. Digitally enhanced by rawpixel.
Four Engine USB Model in the 40x80 foot Wind Tunnel. Large-Scale Upper-Surface Blowing Model using JT15D Engines. Test #441, June 18th, 1974. Original from NASA. Digitally enhanced by rawpixel.
Public DomainFree CCO U.S. Government image for Personal and Business use