Aerodynamic Characterization of a Non-Conventional High-Efficiency Tiltrotor Concept

The growing demand for high-performance vertical take-off and landing aircraft is driving the development of configurations capable of surpassing the speed and range limitations of conventional helicopters. Among these, tiltrotor architectures represent a promising solution for achieving high cruise efficiency. Building on decades of experience gained through major tiltrotor programs -- including Leonardo AW609 tiltrotor, and Next Generation Civil Tiltrotor -- Leonardo has recently investigated an innovative configuration known as the Advanced Tiltrotor Aircraft (ATA). This paper presents a preliminary aerodynamic assessment of a variant of the ATA concept aimed at improving overall aerodynamic efficiency. Early-stage Computational Fluid Dynamics (CFD) analyses were conducted to evaluate the configuration's aerodynamic behavior and estimate potential efficiency gains. To validate the numerical predictions, two dedicated wind-tunnel campaigns were performed on scaled models: a low-speed test at Politecnico di Milano and a high-speed campaign at Centro Italiano Ricerche Aerospaziali, covering Mach numbers up to 0.6. Experimental datasets were processed through a validated in-house toolchain including wind-tunnel corrections and Reynolds/Mach scaling to full-scale conditions. Experimental results show strong agreement with the CFD predictions and indicate a significant improvement in aerodynamic efficiency, supporting further development of the ATA concept and demonstrating the effectiveness of the combined CFD-experimental methodology for innovative tiltrotor design.