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Amazing machines poised to fly travelers into a new era

Thom Patterson, CNNUpdated 16th November 2014
(CNN) — Let's hear it for the gravity-defying magic carpet we call the jet engine.
We use the word "amazing" a lot nowadays, but, if you think about it -- jet engines are truly amazing.
Get ready for more. Because their abilities are about to rise to a whole new level.
Now, I understand that, for many people, raving about a jet engine is about as interesting as extolling the virtues of a rolling pin.
But if you give me a minute, I'll show you why jet engines perform mechanical miracles for people every day:
• They're fast. They make it possible to travel to the other side of the planet in less than a day.
• They move the masses. Every year worldwide, they carry billions of people trillions of miles.
• They're safe. They almost never fail. Statistically, the world's most powerful jet engine -- the gigantic GE90-115B -- is expected to shut down during flight only once in every 1 million flight hours.
That, naysayers, is nothing short of remarkable.
Yet every day, countless fliers benefit from engines without a second thought.
Call us crazy, but some aficionados travel thousands of miles to pay homage to these metallic beasts.
This year, I toured Boeing's huge airliner assembly plant in Everett, Washington, with a group of aviation enthusiasts -- self-described as avgeeks. When we approached a GE90-115B hanging from the wing of a Boeing 777, something happened.
The vibe changed.
Chatter stopped.
Our eyes locked on the engine. Its mere presence literally pulled us closer, like hipsters to a tattoo parlor.
We had to touch it. Some caressed its shiny silver surface. I heard words come out of their mouths like, "cool" and "wow" and "oh my God." You could tell these avgeeks got it -- they understood the engine's significance and its supermechanical abilities.
Here's the part where the engineers weigh in.
Ask engineers to wax poetic about the wondrous properties of the jet engine and they'll forget about the romance and get all technical: "Magic, my a**. It's not about magic. It's about numbers, formulas, aerodynamics and physics!"
NASA describes how jet engines work on a very basic level: The engine's fan blades "spin at high speed and compress or squeeze the air. The compressed air is then sprayed with fuel and an electric spark lights the mixture. The burning gases expand and blast out" through a nozzle in the rear of the engine. The force of the blast pushes the plane forward.
Jet engines have been around since the 1930s, but now engineers are getting really good at making them quieter while burning less fuel and creating less pollution.
One way they're doing it is by making superprecise parts using high-powered laser beams and a process called additive manufacturing -- better known as 3-D printing.
CNN's Jackson Loo recently traveled to a General Electric facility in Ohio, where engineers showed him how they use 3-D printing to make fuel nozzles -- the "heart and soul" of a next-generation engine called the LEAP, which stands for Leading Edge Aviation Propulsion.
The laser melts fine metal powder into a precisely shaped solid metal layer so thin that it's one-third the diameter of a human hair. When it's done, the result is an extremely precise, complicated jet fuel nozzle -- no assembly required. The old way of making nozzles required welding together about 25 separate parts.
GE engineers said it represents the first time additive manufacturing has been used to create a jet engine component tasked with such an important role under high temperature conditions.
Other ways engineers are improving engines include manufacturing fan blades out of strong, lightweight carbon fiber, so they won't be so heavy and engines will burn less fuel; and designing special gear systems that allow the turbines to spin at more efficient speeds to save fuel.
Upcoming improvements like these promise to cut fuel consumption by as much as 15%, reduce noise levels by up to 75% and shrink emissions by more than half compared with current engines.
GE is partnering with a French firm, Snecma, to make LEAP engines. If all goes as planned, by 2016 these engines will be attached to the wings of new single-aisle, narrow-body airliners that will generally seat about 150 to 200 passengers, depending on the configuration.
Rival engine maker Pratt & Whitney also has a superefficient, quieter, cleaner-burning engine for single-aisle airliners, the PurePower PW1100G-JM. And Rolls-Royce reportedly is planning to make its own engine for the single-aisle market.
Why all the new engine designs for single-aisle airliners? Because airlines predict they'll need more than 22,000 of these kinds of planes in the next two decades to handle more travelers and to replace aging aircraft. That number represents 70% of all airliners expected to be built by 2033, according to Airbus.
A generation ago, it often took four engines to carry hundreds of passengers on long-haul flights across oceans. Now, those long-distance flights can be handled by planes with only two engines.
Are they reliable? What happens if you're flying across the ocean and one of the two engines fails? Well, first, it rarely happens. Second, planes are designed to fly with one engine during emergencies. Third, the chance of both engines failing is less than one in a billion flight hours, according to Boeing.
And fourth, you should see how they test these things.
To find out how tough these machines are, engineers throw everything they can into their whirling fan blades, including:
• tons of ice, to simulate hailstorms that planes may have to fly through.
• dead birds, to simulate possible collisions with birds during flight.
• water, sometimes more than 800 gallons a minute, to simulate violent rain storms.
There have been engine failures -- none more tragic than the deadly 1989 crash of United Flight 232 in Sioux City, Iowa. The National Transportation Safety Board blamed the disaster on a crack in a 17-year-old fan disk inside one of the DC-10's three engines. The disk spun apart and cut the plane's hydraulic control systems, which made it nearly impossible to steer. Despite heroic efforts by the crew, 111 of the 296 people aboard died when the plane crash-landed.
Inspection and manufacture of engine parts improved dramatically after the Flight 232 crash, and aircraft control systems these days are radically different. But engines remain loud, although not as noisy as they used to be. And critics say they need to burn even cleaner.
Electric-powered airliners would be both quieter and cleaner, but we're not likely to see those anytime soon. A concept for a battery powered airliner raised eyebrows in 2011. The VoltAir, designed by Airbus' parent company EADS, was billed as being possible by 2036.
With the invention of an airliner with battery-powered engines, the world would reach yet another engineering milestone.
And that also would qualify as truly amazing.
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