For a small company, VX Aerospace of Morgantown, N.C., thinks big as big as major aerospace manufacturers.
Thanks to advances in computer-aided design (CAD), CNC machining and composite materials, the gap in capabilities between the big boys like Boeing and Northrop Grumman and small aerospace companies such as VX Aerospace is narrowing, says Robert Skillen, CEO of VX Aerospace. â€œLittle companies can do interesting things now that you used to think could only happen at large companies, he says.
VX Aerospace’s latest development is the VX-1 KittyHawk aircraft, a blended wing aircraft that combines the fuselage and wings and resembles a manta ray. According to the company, the design which incorporates Chomorat’s C-PLY carbon multiaxial product allows for more useable space inside the aircraft, greater payload capacity, better structural efficiency and better durability.
The VX-1 KittyHawk is the first aircraft to incorporate C-PLY, which has been used in the automotive industry, most notably for fenders on the Audi RS3 Sportback. The non-crimp fabric is comprised of unidirectional layers that are mechanically sewn together. It can have plies with a tow spreading process resulting in thicknesses as low as 75 gsm (grams per square meter) and can make very shallow angles (between ± 20 and ± 30 degrees).
Photo Credit: JEC Composites For small businesses doing aerospace grade work, C-PLY is a game changer, says Skillen, especially because it allows for shallow angles without automatic tape placement. This, in turn, saves the company hundreds of thousands if not millions of dollars in investment, which is beyond the reach of a small business, he says.
VX Aerospace got in on the ground floor with the new C-PLY material by partnering with Chomorat as a test manufacturer for the past several years. VX Aerospace began developing the VX-1 KittyHawk in 2012 after the U.S. Marines retired the H-46 model helicopter, for which it had manufactured parts. Skillen began casting around for a new product.
Inspired by blended wing military aircraft and other airliners, he turned his eye to a blended wing aircraft for the light and unmanned aircraft markets. Skillen designed the VX-1 KittyHawk using CAD yet another tool he says has closed the gap The VX Aerospace VX-1 KittyHawk strives to reduce the carbon footprint with its sleek blended wing design and use of carbon fiber, between small and large aerospace companies.
Twenty years ago, if you had to do CAD modeling to a millionth of an inch or something, the only people that could do that were large companies and it cost hundreds of thousands, if not more, he says. Now I operate a $3,700 CAD program that does fantastic surface modeling. Last October, Skillen brought the aircraft idea to North Carolina State University, where it was quickly selected by Lars Soltmann, a postdoctoral student, for his thesis project on the performance prediction and evaluation of the KittyHawk.
After Soltmann’s computational fluid dynamics and wind tunnel testing showed promising results, VX Aerospace developed a 6 x 7-foot quarter-scale prototype, which was displayed at JEC Europe in March. Skillen didn’t want to invest in high-temperature tooling for the prototype, so the tools were direct-machined out of 39-pound density tooling plastic. C-PLY was then laid up in molds, vacuum infused with epoxy and cured at room temperature for 24 hours.
(Production versions will use high- temperature tooling and C-PLY fabrics with Cytec MTMA 45-1 prepregs.) As a result of its blended wing design, the VX-1 KittyHawk has only six basic airframe parts a top skin, bottom skin and four ribs. Once the initial cure is complete, the parts are assembled using the bottom skin tool as the assembly fixture and Hysol EA 9359.3 adhesive. The entire airframe is then post-cured for approximately 16 hours.
Earlier this year, VX Aerospace assembled the second subscale VX-1 KittyHawk, which will undergo flight testing at NC State this spring. Afterward, the company will make any necessary design changes and prepare to produce either subscale models for the unmanned aircraft market (possibly for collecting agricultural science data) or full-scale aircraft for the manned market.
Perhaps what excites Skillen the most is that the added space inside the aircraft opens up the door to use compressed natural gas (CNG) as aviation fuel. [CNG] is 40 percent cleaner and one-third the cost of aviation fuel, says Skillen. we are hopeful that in the future we’ll be able to develop an aircraft that elegantly incorporates compressed natural gas.
Melissa Haley O’Leary is a freelance writer based in Cleveland. Email comments to email@example.com. C M For more stories like this, visit compositesmanufacturingblog.com and click on the tab marked â€œaerospace.