Chinese regional jet developer COMAC (Commercial Aircraft Corporation of China) has opted for a combined material/service solution from polyaryletherketone (PAEK) supplier Victrex for the aircraft floor brackets in its ARJ21 aircraft. Besides the PAEK polymer, Victrex’s services included simulation analysis, tools for design optimization, and on-site processing support. As a result, greater design freedom, easier manufacturing and less weight compared to traditionally used aluminum led to the replacement of the metal.
PAEK resin-based aircraft seat bracket meets flame retardance standards and can bear loads of over 600 kg.
COMAC´s ARJ21 (Advanced Regional Jet for the 21st Century), a type of turbofan jet, is a short- to medium range regional jet. Within the ARJ21, internal loads are supported by various systems including structural beams. Floor brackets are positioned on these beams to provide support within a gap between the loaded beams and the aircraft flooring above. Typically, these brackets would be manufactured in aluminium, the new solution promotes increased production efficiency via rapid injection molding of the part and is contributing to higher efficiency of the regional jet through weight savings and design improvements that simplify the installation process.
“Today, weight reduction resulting in increased fuel efficiency, is an absolutely essential and critical success factor,” noted Dr. Bai Jie, Brackets Team Leader at COMAC. “This is common knowledge within the aerospace industry, but the full potential and processing efficiency of high-performing polymers are not. As a consequence, we have received support from Victrex as the PEEK experts with material and manufacturing knowledge. During the design process for example, their technical team delivered extensive and valuable support.”
Specifically Victrex provided, as part of its extended services, the simulation analysis, the tools for design optimization, and on-site solutions whenever processing challenges arose. In engineering terms, each of the resulting brackets:
- has a loading capacity of up to 6,000N
- has a working temperature range of -55°C to 135°C (-67°F to 275°F)
- meets FAR 25.853 requirements for flame, smoke, and toxicity
- is lightweight (30% lighter compared to a corresponding aluminum bracket)
- is a viable replacement for the same part manufactured in metal
The distortion tolerance of less than 0.2 mm (0.008 in) is considered optimal for installation in the case of the ARJ21 aircraft. Moreover, the floor brackets are extremely durable and offer an economical 30-year life-cycle, in an industry where safety and reliability are absolute prerequisites.
VICTREX PEEK, employed in the manufacture of both loaded and unloaded aircraft brackets, can be used for components that need a good balance between strength and ductility, resistance to corrosion, and a low rating for flame/smoke/toxicity, while remaining non-conductive.