If you're following the 3-D printing space, you might know that aerospace companies are gung-ho about 3-D printing technology and are quickly embracing it. While General Electric (GE 0.68%) gets the lion's share of the press, its primary competitor, United Technologies (RTX -0.29%), and other aerospace companies are also involved, to varying degrees, with 3-D printing technology.

We're going to explore a sampling -- it's by no means complete -- of how General Electric and United Technologies, which both have divisions that produce jet engines, are using or planning to use 3-D printing in their production processes. Both companies, like many large manufacturers, have been using 3-D printing for prototyping for many years.

Why should aerospace investors care? Aerospace companies that more quickly and successfully put to use 3-D printing throughout their operations will likely sport a competitive advantage over their slower-moving or less effective peers because of the considerable cost savings and innovative possibilities that this technology can unleash.

Why the aerospace industry is all-aboard the 3-D printing train (or plane)
The aerospace industry is keen for 3-D printing for the same reasons many other industries are -- the technology can save time and costs, and it allows for increased innovation.

The cost savings are driven by a few factors, including less raw material use than in traditional manufacturing. This is because 3-D printing is additive, and builds a component up layer by layer, rather than subtractive like traditional manufacturing, which involves whittling away at a chunk of material -- a process that generates much waste. Increased innovation is made possible because 3-D printing allows for designing and producing some parts that can't be made using traditional manufacturing processes.

While raw material cost savings aren't a benefit unique to the aerospace industry, they're a bigger factor than in most other industries because aerospace-grade materials, such as titanium, are very pricey.

There is one big factor rather unique to the aerospace industry: weight. Weight is of critical concern for aerospace components, as small reductions in weight lead to huge savings in fuel costs. 3-D printing allows for some components to be constructed in a such a way as to make them considerably lighter than would be possible using traditional manufacturing techniques. Weight, of course, is a factor among automakers, too, but not to the same magnitude.

General Electric: $255 billion market cap
General Electric's big push into 3-D printing started when it bought Morris Technologies in late 2012. This acquisition gave GE a full-scale 3-D production facility near its aviation division's Ohio headquarters, as Morris was then equipped with 35 3-D printers, mainly comprised of privately held EOS's direct metal laser sintering systems, along with at least one or two of Arcam's (NASDAQOTH: AMAVF) electron beam melting, or EBM, systems.

In mid-2013, General Electric announced it planned to use 3-D printing to produce the fuel nozzles for its new Leap jet-engine, each of which will contain 19 nozzles. This is a huge undertaking, as GE needs to fabricate 85,000 nozzles for the engine orders it has in hand, and expects its annual production to eventually require 45,000 nozzles, according to a Bloomberg article.

The company's massive nozzle production goals would require it to buy at least 60 very pricey 3-D printers, which isn't cost effective. So GE plans to use current technology to ramp up its production while also working with supply chain manufacturers to develop new higher-capacity systems.

GE's reportedly been testing laser sintering systems from both 3D Systems and privately held Concept Laser. Given this fact and that Morris' facility is composed primarily of EOS's DMLS systems, it certainly appears GE plans to primarily use laser sintering technology in its 3-D printing ramp-up. It's worth noting, however, that Avio Aero, which GE acquired last year, has been a major buyer of Arcam's EBM systems for many years.

Notably, General Electric is already the world's largest user of 3-D printing technologies in metals. Additionally, GE plans to invest "tens of millions" in the technology as part of a larger $3.5 billion investment in its aviation supply chain over the next five years. Given GE's might and massive investments, its actions should significantly shape the 3-D printing space going forward.

United Technologies: $106 billion market cap
United Technologies' jet engine division, Pratt & Whitney, seems to fly under the radar (excuse the pun) when it comes to its 3-D printing efforts.

Notably, Pratt used 3-D printing to produce 25 components for its latest quiet and fuel-efficient PurePower Geared Turbofan engine, according to an interesting piece in The Hartford Courant. While Thomas Prete, Pratt's head of engineering, wouldn't reveal to the Courant's reporter which specific parts were 3-D printed, as that information is proprietary, he did note that "some of the 25 parts are simple, such as brackets, and others are more complicated components in the engine's air pathway, a high-temperature and constant-stress area of the engine."

As Prete noted, a big advantage of using 3-D printing is that "designers can now make a single part in one process that otherwise would have been a time-consuming combination of five or 10 pieces that need to be attached and heat-treated before they are ready. That improvement alone saves time and money."

Echoing the sentiments of many other companies across a wide range of industries, Prete stated that the main advantage of 3-D printing is that "engine designers can do things that would have been impossible" using traditional manufacturing techniques.

Additionally, United Technologies, which is based in Connecticut, invested more than $4.5 million when it partnered with the University of Connecticut last spring to establish an advanced 3-D printing lab, the Pratt & Whitney Additive Manufacturing Innovation Center. The company plans to invest more than $3.5 million in the facility over the next five years.

While I don't know which metals printing technology United Technologies' Pratt primarily uses, I do know it does have at least one of Arcam's EBM system at its new center, as a photo of a technician using an EBM machine accompanied the Courant article.

Foolish final thoughts
General Electric and United Technologies, as well as the other aerospace industry players, are in the very early stages of using 3-D printing in their production processes. Given the considerable costs savings and innovative possibilities this technology affords, the companies that more quickly and successfully put it to use will likely enjoy a competitive advantage over their peers. 

You can read about how fellow aerospace companies Lockheed Martin, Airbus, and Boeing are using 3-D printing technology here.