The Boeing 777X and its unmatched foldable wings
Toronto - An unusual scene may become commonplace at airports in a few years if Boeing succeeds in making a new system safe for commercial operation.
We're talking about the foldable wing tips of the 777X, the world's biggest twin-engine airliner. The highly innovative solution by the American manufacturer, which resembles the one adopted in the past by military aircraft boarded on aircraft carriers, will this time have a dual function. It will reduce the space occupied by the jet at airports, but also will provide fuel economy.
The idea of equipping the new 777 with this unmatched feature arose because of the unique wingspan of the aircraft. It will be 72 meters (235 feet, 5 inches), 11 meters (36 feet) more than the wingspan of the first 777 and almost 4 meters (13.1 feet) more than the 747-8. The hinged wing tips alone will measure 3.65 meters (12 feet).
The larger wingspan means higher lift force and more fuel saving, the "Holy Grail" of any new commercial aircraft. These huge wings will provide the jetliner an extra lift, like a giant glider. Like the 787, the 777X family will also make use of a wing design on which the wing tips are raked sharply to reduce drag force.
The problem is that they add an extra wingspan that makes operations on the ground complicated at some airports.
With its wing tips folded, the 777X can reduce its wingspan from 72m to 65m, practically the same as the current long-range versions, the 777-200LR, and 777-300ER. The functioning of the mechanism is not something new. The wing tips are connected to the wings via hinges, and an electric motor extends or collects them. Although the fuselage will be aluminum, the wings will consist of the carbon-fiber reinforced polymer, a strong, super bendy material that's driving the future of aviation.
But, the big question is about safety:
What would happen if one of these tips were released in flight or changed position because of a malfunction?
That is why the FAA, a sort of beacon for other civil aviation authorities in the world as well, is analyzing and requesting from Boeing some safety measures to approve the device.
Among the concerns of the agency is the clarity of information for the crew about the actual position of the wing tips as well as the emergency procedures in case of failure.
Another possibility considered "catastrophic" by the FAA is that gusts up to 75 miles per hour (120 km/h) can bend or damage them in flight, which would certainly cause a tragedy. Imagine a plane of this size with asymmetrical wings.
Boeing will have to prove to the agency that the odds of such events are improbable, however, if any of them could occur the crew will be advised in advance.
Even on the ground, the FAA warns that the signaling lights should be visible on the folded tips. Despite all the fear, it is technically possible to make them safe. The benefits of this development should make operations easier for airlines and airports. If the solution proves to be efficient, it might allow future commercial aircraft designs to be immensely large without entailing high adaptation costs.
Bigger windows, wider cabins
Like the wings, the cabin configuration of the aircraft will also be big, Boeing says.
The 777X will accommodate at least 400 passengers, 34 more than the main competitor Airbus A350-1000. The cabin of the 777X will be 16 inches (40 centimeters) wider than the A350-1000 according to Boeing, allowing economy-class seat widths to be up to 18 inches (46 centimeters). Average airline seat widths vary from 17 to 18.5 inches (43 to 47 centimeters). Airlines will have options to configure each class differently.
The 777X's windows will be 15% larger than the competitor airliners, Boeing also states. New lighting system and enhanced architecture for the cabin's interior design are among other novelties.
Thrust comes courtesy of two fuel-sipping GE9X jet engines, the largest engine ever built for a passenger plane. GE9X will consume 10% less fuel compared to the GE90-115B that currently powering most Boeing 777-300ERs. The GE9X is currently being tested on a specially configured B747.
General Electric has already produced four test engines. Two will be sent to the Renton for installation on the first prototype this year.
The range of the 777X is expected to reach beyond 14,000 kilometers (8,699 miles).
The first copy is expected to enter service in 2020.