Unlike the F-22 or F-35 stealth fighters, the stealth YF-118G is undoubtedly not a household brand and will never enter production like the NGAD. But for a variety of reasons, this plane will always have a special position in aviation history.
A group of engineers from McDonnell Douglas’ Phantom Works created and tested the Bird of Prey, a special stealth fighter that was hidden in Area 51’s secrecy, throughout the 1990s. The “YF-118G” Bird of Prey, unlike most stealth programs, wasn’t intended for active service, but parts of its design and manufacture are still finding their way into Uncle Sam’s hangars today.
But this amazing and exotic airframe’s audacity and eventual success may have had the greatest long-term impact on America’s defense system. While most stealth programs are notorious for being expensive, the Bird of Prey cost less than the price of one F-35 today to get from a pad of paper to the skies over Area 51.
The Lockheed F-117 Nighthawk, the first operational stealth aircraft, was secretly introduced to service by the U.S. Air Force in October 1983. Even though the Nighthawk was given the “F” prefix, which is reserved for fighters, and even had the nickname “stealth fighter,” it was not a fighter at all. The F-117 Nighthawk was an attack aircraft masquerading as a fighter, but make no mistake: it was an attack aircraft, unlike anything the world had ever seen. It had no onboard radar, no guns, and a payload capacity limited to two 2,000-pound bombs.
The Nighthawk served as a turning point for the very direction of aviation technology and air warfare doctrine among the world’s most powerful nations after decades of focus on developing faster, higher-flying aircraft to overcome enemy air defenses.
The Nighthawk was slower and heavier than the F-15s and F-16s in Air Force hangars, but in a world where the F-117 had a radar cross-section of only a little over a tenth of an inch, America’s smallest fighter had a radar cross-section of 82 square feet (0.11 inches).
The F-117 Nighthawk was virtually undetectable to enemy radar, so to speak. The team at McDonnel Douglas’ Phantom Works had stealth goals of their own, and they had just the man they needed to pursue them. Less than ten years later, as Lockheed’s YF-22 and Northrop’s YF-23 competed for the Air Force’s Advanced Tactical Fighter contract, bringing the world’s first true stealth fighter to fruition, the team at McDonnel Douglas’ Phantom Works had stealth goals of their own.
In contrast to Lockheed and Northrop, whose high-performance stealth fighters benefited from direct tax support, McDonnell Douglas was responsible for paying the whole cost of the creation of their new stealth aircraft.
They chose Alan Wiechman to lead the effort to ensure that none of that money was wasted. Before working to create Lockheed’s Sea Shadow, which aims to equip stealth warships for the U.S. Navy, Wiechman gained experience in stealth at Lockheed’s Skunk Works, where he worked on the Have Blue program and its operational descendant, the aforementioned F-117 Nighthawk.
After the Air Force rejected McDonnell Douglas’ Advanced Tactical Fighter proposal in favor of Lockheed’s YF-22 and Northrop’s YF-23, McDonnell Douglas hired Wiechman to jump-start their low-observable efforts on track and to help in the establishment of their Phantom Works division.
Wiechman’s name doesn’t appear as frequently in the annals of aviation history as some other great engineers from the era, including Clarence “Kelly” Johnson. In fact, among the “Secret Pioneers of Stealth Aviation,” according to Aviation Week, he may be the engineer with the “lowest profile.”
However, widespread recognition isn’t always a reliable indicator of achievement. In fact, Wiechman made so many contributions to stealth aviation that the National Defense Industrial Association (NDIA) honored him with a Technical Achievement Award for his work in Low Observable aircraft design before the Bird of Prey was even declassified.
“Because of Wiechman’s work, the United States gained a 15-year lead over potential adversaries that it has not relinquished, and the effectiveness of his designs and products has been thoroughly proven in combat operations,” the award read. Due to budget constraints, Wiechman’s team at the Phantom Works used a rapid prototyping technique, which was revolutionary at the time, to create their new stealth aircraft.
The Phantom Works team employed computers to help in their design work, modeling performance to the best of the era’s computing capabilities, as opposed to designing physical prototypes, putting them to testing, making adjustments, and fielding new prototypes for further testing.
As a result, they were able to create prototype parts that were far more similar to the final product than was possible with earlier methods.
The YF-118G team, however, used other inventive methods as well to construct this revolutionary aircraft. Additionally, they made use of innovative single-piece composite structural designs that did away with many body panel seems that could jeopardize an aircraft’s stealth profile.
One of the trickier parts of building stealth aircraft is getting rid of any noticeable seams or microscopic gaps between the body panels that are linked to the aircraft. In fact, some contend that it’s still a problem for Russian stealth jet designs today.
However, Wiechman and his group didn’t want to create every component from scratch, so they used as many commercially available parts as they could to cut costs and speed up the design process.
With only 3,190 pounds of thrust, the Pratt & Whitney JT15D-5C turbofan engine would have been more at home in a Cessna business aircraft.
The rudder pedals, control stick, and throttle were taken from an A-4 Skyhawk, while the ejection seat, control stick, and throttle were taken from an AV-8B Harrier. Colonel Doug Benjamin, an Air Force test pilot, once jokingly remarked, “The clock was from Wal-Mart and the environmental control system was essentially a hairdryer.”
Four years after the program’s start, in 1996, Wiechman’s team was prepared to demonstrate the viability of their strategy with a flyable prototype.
They had built a technology demonstration with a single engine and one seat that was around 47 feet long, making it slightly longer than an F-16 Fighting Falcon. With an overall span of just 23 feet, or 10 feet less than the F-16, its angular, gull-shaped wings drastically differed from other fighter designs.
The fuselage was blended, and the tail portion was entirely absent, marking the most obvious deviation from conventional fighter design. The aircraft’s shape, the use of movable or flexible covers to disguise gaps, and the placement of the engine deep inside the fuselage—behind a curved inlet duct and in front of an infrared and acoustic defusing exhaust outlet—all contributed to the design’s holistic approach to stealth.
The Bird of Prey was given that moniker after the Klingon warship originally shown in “Star Trek III: The Search for Spock” because of the aircraft’s odd design and combative stance once it was finished.
Air Force Colonel Doug Benjamin flew the YF-118G Bird of Prey for the first time over Groom Lake, better known as Area 51, on September 11, 1996.
Boeing’s Bird of Prey, like its namesake, which would cloak to hide from hostile starships, relied on stealth rather than outstanding performance to accomplish its mission.
Col. Benjamin lifted the aircraft off the ground while leaving the landing gear extended, which revealed the first of several issues.
The platform had performed well during the wind tunnel testing, but all of the tests were done with the landing gear retracted.
Benjamin quickly understood that the gear’s drag was at least three times worse than they had anticipated.
Additionally, the aircraft had stability problems, which were gradually and painstakingly fixed during subsequent flights.
With the one Bird of Prey prototype they had built, the crew completed 37 additional successful flights over the course of the next three years. Benjamin and two Boeing test pilots, Rudy Haug and Joseph W. Felock III flew the aircraft.
By the time it made its final flight in 1999, the aircraft was thought to be aerodynamically stable without the kind of computer correction that contemporary stealth fighters depended on. This was true even though it had gull wings and a tailless design.
The stealthy aircraft’s maximum operational ceiling of 20,000 feet meant it could fly less than half as high as a World War II P-51 Mustang, and its cruising speed of only about 300 miles per hour was slower than a C-130 Hercules. However, like the F-117 Nighthawk Wiechman worked on before it, the Bird of Prey wasn’t intended to outfly the fighters of its day.
Its goals went much beyond that. The Phantom Works team had demonstrated their ability to construct a stealth aircraft for less than $67 million. That means that Wiechman’s Phantom Works successfully created, prototyped, and flew a clean-sheet stealth platform for about $111 million, or less than the price of one F-35B today, when adjusted for inflation to modern money.
“Early investments in technology demonstration projects such as Bird of Prey have positioned Boeing to help shape our industry’s transformation,” Jim Albaugh, president, and CEO of Boeing Integrated Defense Systems said in 2002.
“We changed the rules on how to design and build an aircraft.”
Boeing’s Bird of Prey made its final flight in 1999, but its journey was far from over.
The X-45A Unmanned Combat Air Vehicle, which flew for the first time just months before the Bird of Prey was officially presented to the public in 2002, included the innovations and lessons acquired during the development.
The X-45A was created by Boeing’s Phantom Works, just like the Bird of Prey, but unlike its Klingon cousin, it had an automated flight system.
Boeing claims that the X-45A’s design was largely inspired by the Bird of Prey program. The UCAV incorporated features from its predecessor’s angular design, which defeated radar, and distinctive dorsal intake.
The X-32, which ultimately lost out to Lockheed Martin for the Joint Strike Fighter contract just one year after the Bird of Prey program was shut down, was developed by Boeing using some of the design strategies used for the Bird of Prey.
Today, there are no platforms in service that can draw a direct lineage to Alan Wiechman’s unusual Bird of Prey, and that may be part of the reason it’s not a frequently discussed facet of the American stealth technology race that came at the twilight of the Cold War.
A lesson America has struggled to learn in the decades since the Bird of Prey prowled the skies over Area 51 is that it doesn’t always need a bottomless budget and twenty years’ worth of delays to develop a stealth fighter. However, for a brief period in the 1990s, the Phantom Works showed that.
Atop the museum’s F-22 Raptor in the Modern Flight Gallery of the National Museum of the United States, Air Force at Wright-Patterson Air Force Base is the only YF-118G Bird of Prey ever built.
