Design Evolution and Wind Tunnel Tests of a Three-Lifting Surface Regional Transport Aircraft

This paper deals with the experimental assessment of aerodynamic characteristics an innovative large turboprop aircraft. The configuration is a three-lifting surfaces airplane rear engine installation at tail tips, conceived to carry up 130 passengers and targeting minimum economic environmental impact, which competitive regional jets on short medium hauls. layout output previous research made by authors, it has been selected fully comply market design constraints. An test campaign was required validate aerodynamics, stability, control this configuration. From results first campaign, appeared that aircraft had insufficient longitudinal directional stability. Thus, authors worked improve these characteristics, updating executing second wind tunnel campaign. evolution described in part paper. In part, discuss interference effects among components, detailing how combined downwash coming from both canard wing, as well their wakes, affects empennage aerodynamics. Experimental tests have revealed significant reduction stability due additional downwash, especially low attitudes. Furthermore, found generates non-linearity derivative moderate sideslip angles because its tip vortex impinging vertical tail. Despite detrimental canard, updated proved be statically stable sufficient margin most rearward center gravity. Lessons learned may useful aerodynamicists designers facing similar issues.