Additive Manufacturing Is Reshaping Aviation

Advanced manufacturing technologies are leading to smaller jet engines.

The aviation company Pratt & Whitney is exploring whether technology known as additive manufacturing could be used to develop more compact jet engines that could make commercial airplanes lighter and more fuel efficient.+

Pratt & Whitney already uses two additive manufacturing techniques to make some engine components. Instead of casting metal in a mold, the methods involve forming solid objects by partially melting a metal powder with either a laser or an electron beam. Other aircraft makers use similar technology; GE, for example, creates fuel nozzles for jet engines using its own additive manufacturing techniques (see “Breakthrough Technologies 2013: Additive Manufacturing”).+

The methods being used by GE and Pratt & Whitney are more complex and sophisticated than desktop 3-D printing, which involves creating objects by depositing ultrathin layers of material successively (see “The Difference Between Makers and Manufacturers”).+

Additive manufacturing processes can reduce waste, speed up production, and enable designs that might not be feasible with conventional production processes. The novel shapes and unusual material properties the technology makes possible—such as propeller blades optimized for strength at one end and flexibility at the other—could change the way airplanes are designed.+

One possibility being explored by Pratt & Whitney is engines with fewer parts, which would need less assembly and be cheaper to make. Frank Preli, chief engineer for materials and process engineering at the company, anticipates the possibility of radical new aircraft designs “like many engines embedded in a wing for ultra-aerodynamic efficiency.”

Such a design could have many benefits, says Mark Drela, a professor of aeronautics and astronautics at MIT. Distributing engines along the trailing edge of wings and in the rear of the fuselage can theoretically cut fuel consumption by 20 percent and decrease an aircraft’s weight. These benefits “add up to very large fuel burn reductions,” Drela says. Savings of 50 percent “are not inconceivable.”+

To get to that point, Preli says, additive manufacturing techniques need to improve to allow for higher precision. Once researchers understand the fine, molecular-scale physics of how lasers and electron beams interact with powders, he says, “that will lead to the ability to put in finer and finer features, and faster and faster deposition rates.”+

It makes sense that the aerospace industry has been among the first to adopt additive manufacturing—even slight improvements to performance or small reductions in weight can lead to big fuel savings, justifying the high initial cost of printing a part.

You Might Not Have Broadband Anymore

New regulations on Internet service providers are changing the way they can describe their service.

If you don’t think your home Internet service is as fast as it ought to be, federal regulators are inclined to agree.+

On Wednesday the U.S. Federal Communications Commission proposed new rules for regulating the Internet (see “FCC Chief Proposes Broader Net Neutrality Rules”), which the FCC says will help it ensure that Americans have access to “more and better broadband.” But due to a separate decision the FCC made last week to change its very definition of “broadband,” many fewer people even have it to begin with.+

The new broadband standard calls for download speeds of 25 megabits per second (mbps) and upload speeds of three mbps—up from four and one, respectively. FCC chairman Tom Wheeler recently said 25 mbps is “fast becoming ‘table stakes’ in 21st century communications,” and the White House, in a recent report, called this speed the “baseline to get the full benefits of Internet access.” But as the FCC has also reported, only about 15 percent of residential connections had download speeds of at least 25 mbps at the end of 2013. Currently the average connection speed in the U.S. is 11.5 mbps, according to Akamai; more than three-fourths of residential connections are above three mbps, according to the FCC.

Even if you do buy broadband access, though, that doesn’t necessarily guarantee that you get it. A recent analysis by the independent research groupMeasurement Lab showed that between May 2013 and February 2014, many customers of big service providers including Comcast, Time Warner Cable, and Verizon often experienced download speeds of less than four mbps. This chart produced by the lab captures the dramatic plunge in bandwidth:+

Measurement Lab concluded that this degradation of service was the result of business disputes between consumer ISPs like Comcast and Time Warner and companies, like Cogent and Level 3, which connect those consumer ISPs to the greater Internet. Specifically, the disagreements were over who should be obligated to pay for upgrades at interconnections between the companies’ networks. If the FCC’s proposed rules, which face a vote on February 26, are enacted, the agency for the first time will have the authority to police interconnection-related business dealings. The agency’s officials hope this and the other changes eventually mean that paying for broadband actually guarantees you very fast service.