How Flying Wings Will Work

Anyone who has seen the B-2 stealth bomber knows that the flying wing isn't new to military aircraft. In fact, the flying-wing design dates back to the first half of the 20th century. Beginning in the late 1920s, Jack Northrop, founder of Northrop Aircraft Co. (known today as Northrop Grumman), led the design of several military planes based on the flying-wing design. Later, Northrop's company was one of those contracted by the U.S. Army Air Corps to build a longer-range bomber during World War II. Northrop delivered the YB-49.

Photo courtesy U.S. Air Force Northrop Aircraft Co. pioneered the flying-wing design and developed the YB-49, which first flew in 1947.

The YB-49 was the culmination of years of development, which began with the Northrop Model 1 (N-1M), a twin-engine flying model, in 1939. Northrop began improving on the N-1M and developed the XB-35 and YB-35, both of which were propeller-powered flying wings. In 1946, the XB-35 took its first test flight. Jet propulsion was then added to the YB-35 model, creating the YB-49. A year later, the YB-49 took its maiden flight in California.

Despite its early success, the YB-49 project was cancelled in 1948 following an accident that killed two test pilots and three engineers. With World War II over, the U.S. military suspended any further development of a flying-wing bomber. The flying-wing design would be resurrected in the 1980s with the development of the B-2 stealth bomber, which was also built by Northrop Grumman. Development of the B-2 began in 1981 to replace an aging fleet of B-52 bombers.

Photo courtesy U.S. Air Force The B-2 bomber is a descendent of the YB-49 bomber.

Flying Wings Go Global Although there was no collaboration between designers, development on flying wings began at about the same time in America, the Soviet Union and Germany: the 1920s. One prominent Soviet designer, Boris Ivanovich Chernanovski, worked on flying wings from 1921 to 1940. The Horten brothers of Germany also created several working wings.

Although the influence of the YB-49 is obvious in the B-2 bomber, there is one key difference -- the B-2 uses stealth technology to make it nearly invisible to radar. The B-2 made its public debut in 1988, but technical problems delayed its use in combat for more than a decade. In 1999, the B-2 bombers were initiated into combat when they dropped satellite-guided bombs on Yugoslavia.

With proof that the flying wing works in combat, the next logical step is to develop a commercial jet with a flying-wing design.

While flying-wing designs have been used by the military for years, we've yet to see a flying-wing aircraft pull up to a gate at our local airport. Researchers are working to change that. Boeing is developing a double-deck, 800-seat, flying-wing commercial jet that could be ready by 2015. However, that production date might be moved up depending on the success of Airbus' gigantic A-380 jumbo jet, which could put pressure on Boeing to deliver their flying-wing jet sooner than planned. The A-380 isn't a blended-wing body design, but it is a double-decker capable of carrying 600 or 800 passengers (depending on the configuration).

Image courtesy NASA The flying wing will be only 67 feet (20.4 meters) wider than the Boeing 747-400. It will be able to use existing runways.

	Flying Wing	747-400
Wingspan	289 feet (88.1 meters)	211 feet (64.3 meters)
Height	40.9 feet (12.5 meters)	63 feet (19.2 meters)
Length	160.8 feet (49 meters)	232 feet (70.7 meters)
Engines	three high-bypass-ratio jet engines	four turbofan engines
Passenger Capacity	800	up to 660
Range	7,000 miles (11,265 km)	7,200 miles (11,587 km)
Cruising Speed	486 knots (560 mph / 900 kph)	490 knots (563 mph / 908 kph)

Engineers at Boeing's Phantom Works research lab have teamed up with NASA and several research universities to develop the flying-wing jumbo jet. The aircraft will be unlike anything you've ever flown in. It has done away with the fuselage and tail section. The only thing left is the wing, which contains everything needed to fly. Here's a look at the architecture of Boeing's flying wing:

• Body - The flying wing will be constructed out of advanced composite materials and be divided by 10 intermediate ribs that run from the front to the back of the aircraft. These ribs divide the aircraft into 10 separate passenger bays. The body is fused together with the engine and wings, creating one lifting surface. This lightweight design allows the flying wing to use 25 percent less fuel than a 747.

Image courtesy NASA

• Passenger bays - The aircraft will carry 800 passengers in a double-deck cabin that is divided into five bays per deck. Most passengers won't have a window, so the aircraft will have video screens that display window views. Each bay will have doors at the front and back to make emergency exits easier.
• Engines - Three jet engines, called high-bypass-ratio engines, will be constructed into the rear of the aircraft's body. Air that is on and near the surface of the wing will flow through the flying wing's curved inlets and into its engines.

Researchers still face several challenges in developing a full production model of the Boeing flying wing. Cabin pressurization is not a problem on today's tube airplanes, but will pose a problem in the flying wing's much larger cabin. It will require the development of a new pressurization system. Also, at today's aircraft speeds of about 600 mph (966 kph), drag becomes increasingly problematic with a flying-wing aircraft because the wing is much thicker than that of a traditional airplane. Computer analysis and wind tunnel testing at NASA's Langley National Transonic Facility is expected to determine the stability and performance of the flying-wing design.

Once the technical challenges are overcome, perhaps Boeing's biggest obstacle will be convincing the air-travelling public that the flying wing is just as safe as conventional airplanes. There's some concern that the public will be apprehensive about getting on an aircraft with such a radical design. They may have seen the B-2, but Boeing's flying wing will be much larger than that. There may also be some fears about a plane that carries 800 passengers and what that might mean in emergency situations.

The flying wing has the potential to be more than just a commercial passenger jet. It could also be used as a cargo aircraft and a very long-range military airlifter. With the airline industry bursting at the seams, the flying-wing design may help airlines meet the needs of an increasingly mobile society in the 21st century.