Chinese commercial jet opts for PEEK-based tubing

China's efforts to develop a domestic passenger jet are finally close to fruition. And despite those that claim the technology deployed in the Commercial Aircraft Corporation of China (COMAC) C919 is already five years behind that of Western aeroplanes due to numerous delays and that the C919 borrows extensively from the Airbus A320 that is also assembled in China, it does employ some cutting edge technologies, carbon fiber composites in the wingbox, for example. Another exotic material the C919 has opted for its polyetheretherketone (PEEK) resin for the high-voltage cable conduits that are normally made of metal.

The new thermoplastic solution can deliver weight savings of up to 45% when compared with titanium equivalent tubing and is being supplied through the partnership of Beijing FeiHang Jida Aviation Technology and PAEK supplier Victrex (West Conshohocken, PA). This weight reduction can lead to both improved fuel efficiency and a reduction in CO₂ emissions. Victrex Pipes are typically used in the replacement of aluminum, titanium, and stainless steel tubing systems.

The Victrex PEEK-based tubing surpassed airworthiness testing in China, which included maintaining operational performance under impact, loads, temperature variations, and other environmental conditions. With the technical expertise and support of Victrex, the companies were able to design a lightweight, cost-effective high-voltage cable protection system within a much shorter development cycle.

The durable tubing system also serves as a shock absorber in the protection of the cables. "Victrex is extremely focused on delivering innovative, high performance, cost-effective solutions that can help airframers and tier suppliers achieve their goals," stated Xue Wei, Aerospace Key Account Manager at Victrex. "It is very rewarding to partner with industry-leading companies like Beijing Feihang to achieve the best results, not only in component performance, which will contribute to COMAC's ability to deliver their lightweight, next-generation aircraft, but also in delivering improvements in manufacturing efficiencies."

Victrex collaborated with the engineering teams to design a system that is able to take advantage of a much quicker manufacturing process, one that does not require machining or anti-corrosion treatments as metals would. Victrex Pipes are also able to be bent, formed, and flared using heat and conventional tube bending equipment to meet strict interior design requirements and space limitations. Victrex also works with several customers on jointing technologies that allow the design of continuous systems.

PEEK tubing also delivers excellent fire/smoke/toxicity (FST) performance, is very ductile and corrosion-resistant, and provides high dielectric strength, which is essential in high-voltage environments. These solutions are also being used in the energy and industrial industries due to their ability to maintain durability in high-temperature, high-pressure, and corrosive operating conditions. In addition, the smooth inner bore of Victrex Pipes allows for an ease of flow - a key benefit in the case of fluid transportation.

Providing further assurance in the quality of its products, Victrex has recently obtained the AS9100C/ISO9001:2008 aerospace certification, which requires that a quality management system is in place to consistently provide products that meet customer and applicable legal and regulatory requirements.