Certification by birdstrike analysis on C27J fullscale ribless composite leading edge

The objective of this paper was to design, manufacture and test a composite leading edge, without ribs, able to satisfy birdstrike requirements specified by certification authorities.The leading edge configuration was validated through an extensive campaign of experimental tests performed firstly on small sample to determine the mechanical properties [1], then through the analysis and testing of a small representative structures of the wing leading edge [2] and [3]. The explicit finite element software MSC.Dytran®[4] was chosen for the numerical investigation and a validated simulation methodology was developed to predict the birdstrike scenario.The evaluation of numerous birdstrike scenarios allowed an improved design efficiency and safety and led to a significant reduction of certification costs. The most important achievement was a ribless wing leading edge made of FML, aluminium and honeycomb able to satisfy the birdstrike resistance test specified by the Federal Aviation Regulation [5]. This configuration allowed a considerable reduction in weight and manufacturing costs.

► A ribless composite leading edge was designed, tested and validated to satisfy the certification requirements.
► The experimental tests were performed firstly on small sample to determine the material's mechanical characteristics.
► The ribless leading edge configuration was validated by an experimental test with an 8-pound bird at a speed of 250 kts.
► This solution meets the structural requirements and reduces the manufacturing process thanks to the absence of ribs.