If you want a better plane, start with a better material. Then combine that with innovative processing and design. That’s the thinking behind production of the world’s first completely vacuum infused CFRP single-engine, light-sport aircraft, according to Naresh Sharma, CEO of NASHERO. Based in San Giovanni in Croce, Italy, the small startup company was launched in 2010 and offers business and engineering consulting as well as high-precision composite and metal prototype fabrication. The aircraft – its first product – is not your run-of-the-mill recreational plane.
“The first aircraft design is a high-performance, two-seat full carbon light aircraft that is designed for the pilot-owner as a means for traveling safely from A to B with comfort and ease,” Sharma says. “To us, high performance implies extremely low fuel consumption for the distance travelled and extremely low environmental impact. Our aircraft, on a per seat mile basis, has significantly lower emissions compared to low-emission hybrid automobiles.”
The plane also features high-end safety features. These include a safety cell design, allowing the aircraft to take a frontal crash with minimal transfer of impact energy to the pilot or passenger. A second safety element is an integrated aircraft ballistic parachute recovery system – essentially a parachute for the entire plane – embedded in the fuselage.
The choice of materials and fabrication technique was critical to achieve the desired performance. Aluminum alloys are typically used to construct small aircraft, but composites offer several advantages. These include lower weight, corrosion resistance, high fatigue strength, high stiffness for increased flutter resistance, superior crash-absorption capabilities, the ability to produce sculpted shapes and the potential for better aero-elastic tailoring of flying surfaces. NASHERO opted for CFRP because it enables creation of the stiffest and strongest structure, while remaining lightweight. A lighter overall structure accommodates a lighter engine and a larger payload.
Nearly all of the airplane’s structural parts are composed of CFRP. One exception is the engine mount, which by regulation must hold its strength to temperatures above 1000 C. In addition, areas where a load must be transferred from one part of the structure to another use metal, such as aluminum and titanium embedded as hard points between layers of reinforcement fibers.
NASHERO selected a range of CFRP materials for the light-sport aircraft, including regular woven hybrid aramid-carbon twill, unidirectional tape, multi-axial spread tow stitched fabric and spread tow carbon fiber fabric up to 24K filaments. By its nature, the fiber itself is free of internal defects, says Sharma. In addition, crack propagation from one fiber to another is difficult. That combination makes the fatigue life of CFRP almost infinite, Sharma says.