In the realm of military aviation, few aircraft have made as lasting an impression as Boeing’s YF-118G Bird of Prey. Designed during the 1990s, this stealth jet prototype was indeed a groundbreaking effort to develop next-generation technology for use in a place within future stealth aircraft.
The Bird of Prey, YF-118G, is an ungainly craft, and its flying quality is nothing special; it was never intended for mass production. Rather, it was to be a proof-of-concept testbed with the most advanced stealth features conceivable: faceted surfaces, and radar-absorbing materials. Fitted with all these remarkable technologies and with a 23-foot wingspan bad for the Bird of Prey was a technological marvel.
Running from 1992 until 1999, with its first test flight in 1996 at the infamous Area 51, it showed the ambition of Boeing to try and leapfrog the competition. The main objective of the aircraft was to take the military’s demand for reliable next-generation stealth technology into the new century. It did so, as the Bird of Prey influenced future designs such as the X-32 Joint Strike Fighter and the X-45A UAV.
The Bird of Prey featured next-generation stealth concepts in development, with working faceted surfaces and radar-absorbing materials integrated into the plane’s “skin,” featuring a reduced radar cross-section to make it harder for enemy radar to identify. Powered by one Pratt & Whitney JT15D-5C Turbofan engine, developing 3,190 pounds of thrust, it had a maximum speed of 300 miles per hour and reached a ceiling of 20,000 feet.
It was not designed to be the next great flying machine but was to be a stepping stone for new stealth technology. The YF-118G wove itself so deeply in design and capability with other Boeing aircraft that the company donated the prototype to the National Museum of the Air Force. The true legacy of the Bird of Prey will be found in future aircraft like the F-35 Lightning II, which takes vital experience learned from this pioneering prototype.
Finally, the U.S. Air Force’s B-21 Raider is approaching operational status, but even now, work may be underway on its eventual replacement. That development cycle seems to never end, and indeed is a key part of the military’s plan for ensuring that it remains competitive at the global level. Technology demonstrators such as the YF-118G Bird of Prey form an integral part of this process, feeding into not only the design and development but also the full-scale production of many weapons systems.
The Bird of Prey was a highly classified demonstrator designed as a testbed for stealth technologies destined for operational employment in future fighter and bomber aircraft. At the time of its use, the world’s very first operational stealth aircraft, the F-117 Nighthawk stealth bomber, was already flying with the U.S. Air Force, while the B-2 Spirit stealth strategic bomber was coming online. Presumably, that knowledge trickled down from test flights of the Bird of Prey into aircraft such as the F-22 Raptor and F-35 Lightning II stealth fighter jets.
Although the YF-118G Bird of Prey program was rather short-lived, the technology and capability it helped to develop live on through the numerous aircraft it influenced. The Air Force likely has similar technology demonstrators now, testing the weapons systems and stealth capabilities of tomorrow.