Lockheed Have Blue

Lockheed Have Blue was the code name of the proof-of-concept stealth fighter demonstrator designed by Lockheed's Skunk Works and tested at Groom Lake, Nevada. It was the first fixed-wing aircraft whose external shape was defined by radar engineering rather than aerospace engineering: faceted surfaces deflected radar waves away from the emitter, greatly reducing its radar cross-section, and highly swept wings and inward-canted vertical stabilizers earned it the nickname the Hopeless Diamond. It grew from a 1974 inquiry by the Defense Advanced Research Projects Agency to five manufacturers about low-observability aircraft, after radar-guided missiles and guns had downed many American aircraft in Vietnam and the 1973 Yom Kippur War showed the same vulnerability. The first operational aircraft made its maiden flight on 1 December 1977, and two flyable vehicles were constructed, both lost to mechanical problems. Have Blue was judged a success and paved the way for the first operational stealth aircraft, the Lockheed F-117 Nighthawk.