An F-22 Raptor flies over the Pacific Ocean near the Hawaiian Islands in March 2012. That aircraft design got its start at the Skunk Works around 1990 as the YF-22 prototype, and it went through nearly 44,000 wind tunnel test hours, 13,000 material sample tests, six years of development, and "a trio of program rephasings mandated by Congress," according to Lockheed. The first flight of an F-22 model came in September 1997 -- followed by nearly 3,500 additional flights and more than 7,600 test hours in the engineering and manufacturing development phase. In 2005, the Air Force finally declared the aircraft operational as the F-22A.
June 23, 2013 8:45 AM PDT
Photo by: U.S. Air Force photo/Tech. Sgt. Michael Holzworth