Flying wing
A flying wing may have various small protuberances such as pods, nacelles, blisters, booms, or vertical stabilizers.
The basic flying wing configuration became an object of significant study during the 1920s, often in conjunction with other tailless designs.
Military interest in the flying wing waned during the 1950s with the development of supersonic aircraft, but was renewed in the 1980s due to their potential for stealth technology.
A flying wing may have various small protuberances such as pods, nacelles, blisters, booms, or vertical stabilizers.
These compromises are difficult to reconcile, and efforts to do so can reduce or even negate the expected advantages of the flying wing design, such as reductions in weight and drag.
Further difficulties arise from the problem of fitting the pilot, engines, flight equipment, and payload all within the depth of the wing section.
Another solution is to angle or crank the wing tip sections downward with significant anhedral, increasing the area at the rear of the aircraft when viewed from the side.
This vector essentially pulls the trailing wing forward to cause "proverse yaw", creating a naturally coordinated turn.
[8] Germany's Hugo Junkers patented his own wing-only air transport concept in 1910, seeing it as a natural solution to the problem of building an airliner large enough to carry a reasonable passenger load and enough fuel to cross the Atlantic in regular service.
He believed that the flying wing's potentially large internal volume and low drag made it an obvious design for this role.
In 1919 he started work on his "Giant" JG1 design, intended to seat passengers within a thick wing, but two years later the Allied Aeronautical Commission of Control ordered the incomplete JG1 destroyed for exceeding postwar size limits on German aircraft.
The BICh-11, developed by Cheranovsky in 1932,[13] competed with the Horten brothers H1 and Adolf Galland at the Ninth Glider Competitions in 1933, but was not demonstrated in the 1936 summer Olympics in Berlin.
During the Second World War, aerodynamic issues became sufficiently understood for work on a range of production-representative prototypes to commence.
In Nazi Germany, the Horten brothers were keen proponents of the flying wing configuration, developing their own designs around it - uniquely for the time using Prandtl's birdlike "bell-shaped lift distribution".
[19] Several other late-war German military designs were based on the flying wing concept, or variations of it, as a proposed solution to extend the range of otherwise very short-range of aircraft powered by early jet engines.
[20] It combined a flying wing, or Nurflügel, design with a pair of Junkers Jumo 004 jet engines in its second, or "V2" (V for Versuch) prototype airframe; as such, it was the world's first pure flying wing to be powered by twin jet engines, being first reportedly flown in March 1944.
The unflown, nearly completed surviving "V3," or third prototype was captured by American forces and sent back for study; it has ended up in storage at the Smithsonian Institution.
[21][22] The Allies also made several relevant advances in the field using a conventional elliptical lift distribution with vertical tail surfaces.
[25] The British Armstrong Whitworth A.W.52G of 1944 was a glider test bed for a proposed large flying wing airliner capable of serving transatlantic routes.
[26][27] The A.W.52G was later followed up by the Armstrong Whitworth A.W.52, an all-metal jet-powered model capable of high speeds for the era; great attention was paid to laminar flow.
[27][28] First flown on 13 November 1947, the A.W.52 yielded disappointing results; the first prototype crashed without loss of life on 30 May 1949, the occasion being the first emergency use of an ejection seat by a British pilot.
[30] The YB-49 presented some minor lateral stability problems that were being rectified by a new autopilot system, when the bomber version was cancelled in favour of the much larger but slower B-36.
In the Soviet Union, the BICh-26, became one of the first attempts to produce a supersonic jet flying wing aircraft in 1948;[31] aviation author Bill Gunston referred to the BICh-26 as being ahead of its time.
However, modern computer-controlled fly-by-wire systems allow for many of the aerodynamic drawbacks of the flying wing to be minimized, making for an efficient and effectively stable long-range bomber.
[42] The design is claimed to offer low wave drag, high subsonic efficiency and reduced sonic boom.
Since the end of the Cold War, numerous unmanned aerial vehicles (UAVs) featuring the flying wing have been produced.
Nations have typically used such platforms for aerial reconnaissance; such UAVs include the Lockheed Martin RQ-170 Sentinel[43][44] and the Northrop Grumman Tern.
