Eight F-5E fighters and four F-5F two-seat trainers ordered from the manufacturer in 1985 in two separate contracts and delivered between December 1985 and January 1987. These aircraft were of the late production standard with flattened ‘shark’ nose, and a dorsal ILS antenna but not the extended fin fillet. Used initially for fighter interceptor duties by the 6th Fighter Squadron, but after the F-16s arrived they were used mainly for the air-to-ground role.
The Flying Wing aircraft configuration has been around since the early days of aviation. The flying wing is a fixed wing airframe capable of sustaining a controllable flight profile without the need of lifting systems such as canards or tail mechanism. Experimentation with flying wing designs began early in the 1920s. The configuration was championed by those who thought that it was the logical evolution of an airframe. As technology caught up with design, the flying wing concept would become the standard aircraft fuselage design, they thought. Many individuals experimented with flying wing configurations, most notable, the Horten Brothers in Germany and, who was to be called the father of the flying wing in the United States: Jack Northrop. Both the Horten brothers and Jack Northrop eventually managed by build an actual flying wing platform. The Horten’s effort was to be curtail by the cloud of war in Europe. The same cloud that gave birth to the first true expression of the flying wing concept: the YB-49.
An aircraft based on a flying wing airframe has always been believed to posses an increase in operational range, better speed to power ration, and more weight-lift capability compare to a conventional airframe design. These advantages were the reason the military was behind every major attempt to field a flying wing aircraft in modern times. There were many attempts to field a serviceable flying wing aircraft, and also many failures. That was until the YB-49 first took to the air. The YB-49 was the first truly serviceable winged aircraft. It posses the entire trait marks that engineers were looking for. Range, speed, power ratio and an enormous payload capacity. But what the YB-49 lacked, and would lead to the eventual cancellation of the project; was stability. The YB-49 lacked the ability to make sharp turns. It was also deficient in projecting a stable operational line for bombing runs. Deficiencies that with today’s computer power could be easy overcome. But in the 1950s, these facts made the aircraft impractical for military operations, thus the Air Force was forced to terminate the project. After the Air Force’s initial order for termination of the program, Jack Northrop and his top engineers tried to sell the YB-49, with its massive payload capabilities, to the civilian aviation community. He envisioned a fleet of commercial flying wing carriers traveling the country. He even made an Ad commercial relating the advantages of the commercial flying wing. It was to no avail. If the wing was not stable enough for experience Air Force pilots, it certainly could not perform at a civilian standard. This realization, for all practical matters, ended the brief life of the YB-49. It would be more than thirty years before another flying wing configuration would take to the air. But when it did, it was a spectacular sight, such as was the first time the YB-49 flew. The B-2 Stealth Bomber is the realization of years of experimentation, couple with unprecedented advances in technology, airframe design and avionics. These advances lead to the production of the finest expression of a flying wing configuration design. Could there be a commercial-type version of the B-2?
In the mid 1970s a quiet research program was commenced by the Boeing Corporation with the objective of adapting a flying wing configuration design and develop it into a passenger-carry airframe. After an extensive period research and design experimentation; Boeing engineers came out with two main flying wing concepts for a passenger airliner. They unveiled them in January 1998. The first concept was the C-wing configuration. The C-wing concept is centered around a fuselage structure of tubular shape fitted with small horizontal winglets to be placed at the end of the vertical ones. The wings on the C-concept were designed to be swept at an angle of 35 degree, the same goes for the horizontal winglets. This fuselage configuration was adopted by the design team for its ability to reduce drag on the wings. The C-wing was design from its conception to disperse payload evenly throughout the airframe in order to reduce high amounts of lift. The airframe in a C-wing concept would be equip with a canard system to be utilized as a control mechanism in cruise flight conditions. The aircraft was conceived to be propelled by two forward and two aft turbojet engines. But, as it was the case with the first generation of flying wing platforms, the fuel consumption-to-performance ratio was in the negative. This fact alone will probably lead to the shut-down of the whole program. Sensing this problem, Boeing engineers also studied a modification to the original C-wing platform. In this alternative, the aircraft will be powered to the air by only three engines. Early design experimentation with this concept had indicated that the design would achieve a better aerodynamic profile than the one mounted with four engines. Still, this concept is not as promising as the newest Boeing pre-design mock-up.
Besides the C-wing concept, in 1998, Boeing unveiled the most far reaching flying wing platform concept in the history of civilian aviation: the Blended Wing Body Platform. The blended wing concept is the pinnacle of civilian aviation design and engineering prowess. The blended wing airframe is very similar in shape and control systems orientation to the amazing B-2 bomber. The concept is simple enough. The wing fuselage will also serve as an engine mounting platform, and again, like the B-2, the engine’s inlets will be absorbed by the wing’s frame. There considerations for a two engine configuration of the blended wing. Research has also demonstrated that a four engine version can perform equally successful. Control mechanisms for directional stability, such as flaps, will be house on small winglets at the end of each wing tip. The complete aircraft will be fly-by-wire, thus enhancing its flying stability and optimizing its avionics package. The operational profile for this amazing aircraft is ambitious. It is design to carry a load of eight hundred passengers and crew members to a distance of over 7,100 nautical miles. It will be fitted with all the comforts of the modern era. The aircraft will have state of the art galleries, lavatories, and a sound and video system. An improved row sitting system that will enable the passenger to roam around the “wing” on flight is on the design board. But maybe the most unique cabin feature of this concept, is the proposed forward view windows mounted along the curve of the wing. A concept first developed by Jack Northrop in the late 1950s. This feature will give the passenger the ability to see through the window at the “world below”. A view normally only experienced by the aircraft’s crew.
Could Boeing or any other company find operating a flying wing concept aircraft profitable? Research and development data has shown that the time of the commercial flying wing has arrive. Technology, unlike before, is now on our side. The question is not so much as “if” and more as “when”. We don’t know when the time will come. But we certainly know that is far approaching. Approaching the visions of so many giants of aviation, approaching history. We are close, very close.