YF-118G Bird of Prey, A Short History: The National Museum of the United States Air Force outside of Dayton, Ohio is home to more than 360 aircraft and missiles. Its collection includes such truly notable airplanes as the B-29 “Bockscar” that dropped the “Fat Man” atomic bomb on Nagasaki, the B-17 “Memphis Belle” and the Boeing VC-137C SAM 26000 that had the callsign Air Force One when it was used by Presidents John F. Kennedy, Lyndon Johnson and Richard Nixon.
In the Cold War gallery of the museum, near a Lockheed Martin F-22A Raptor is a truly special aircraft – the one-of-a-kind Boeing YF-118G, a black project aircraft that was developed to demonstrate stealth technology.
Developed by McDonnell Douglas and Boeing in the 1990s it was soon dubbed “The Bird of Prey,” named for its resemblance to the Klingon spacecraft from the science fiction series Star Trek, as well as the movie Star Trek III: The Search for Spock.
The secret project ran from 1992 to 1999 and the single-seat aircraft was a demonstrator used to test “low observable” stealth techniques as well as new methods of aircraft design and construction. The aircraft, which was tested at the top-secret “Area 51,” first flew in 1996 and made a total of 38 flights, where it was used to determine ways to make aircraft less observable not only to radar but also to the eye.
The program also validated new ways to design and build aircraft using large single-piece composite structures, as well as “virtual reality” computerized design and assembly and disposable tooling. It was powered by a single Pratt & Whitney JT15D-5C turbofan that provided 3,190 pounds of thrust and had a maximum speed of 300 miles per hour, and a ceiling of 20,000 feet.
The aircraft made its final flight in 1999 and it was declassified three years later when its design techniques had become standard practice. Boeing has used those techniques in the development of X-32 Joint Strike Fighter demonstrators and later in its X-45A Unmanned Combat Air Vehicle prototype.
The lasting legacy of the Bird of Prey was its ability to demonstrate advances in stealth concepts, notably the “gapless” control surfaces that were developed to blend smoothly into the wings to reduce radar visibility, while the engine intake was completely shielded from the front. Yet, despite its advancements, the National Museum of the United States Air Force noted that it still utilized some “off the shelf” technology to reduce costs while also speeding the production. This included a control system that is all-manual with no computer assists, while its landing gear was adapted from Beech King Air and Queen Air aircraft.
Boeing donated the sole YF-118G Bird of Prey to the museum in 2002 and it has been on display since 2003 – where despite its stealthy technology is ready to be seen and photographed by visitors.
Peter Suciu is a Michigan-based writer who has contributed to more than four dozen magazines, newspapers and websites. He is the author of several books on military headgear including A Gallery of Military Headdress, which is available on Amazon.com.