Analysis of Coordinated Steering Performance in Multi‑wheel Landing Gears

During aircraft ground steering， the nose landing gear （NLG） tires of large transport aircraft often experience excessive lateral loads， leading to sideslip. This compromises steering safety and accelerates tire wear. To address this issue， the rear landing gear is typically designed to steer in coordination with the nose wheels， reducing sideslip and improving maneuverability. This study examines how structural parameters and weight distribution affect the performance of coordinated steering in landing gear design for large transport aircraft. Using the C-5 transport aircraft as a case study， we develop a multi-wheel ground steering dynamics model， incorporating the main landing gear （MLG） deflection. A ground handling dynamics model is also established to evaluate the benefits of coordinated steering for rear MLG during steering. Additionally， the study analyzes the impact of structural parameters such as stiffness and damping on the steering performance of the C-5. It further investigates the effects of weight distribution， including the center-of-gravity （CG） height， the longitudinal CG position， and the mass asymmetry. Results show that when the C-5 employs coordinated steering for rear MLG， the lateral friction coefficients of the NLG tires decrease by 22%， 24%， 26%， and 27%. The steering radius is reduced by 29.7%， and the NLG steering moment decreases by 19%， significantly enhancing maneuverability. Therefore， in the design of landing gear for large transport aircraft， coordinated MLG steering， along with optimal structural and CG position parameters， should be primary design objectives. These results provide theoretical guidance for the design of multi-wheel landing gear systems in large transport aircraft.