Aerodynamic simulation and control analysis of an aircraft emergency tailplane system

This paper presents an improved design to address the issue of elevator jamming in aircraft. The proposed solution involves an auxiliary spare tail system, featuring a foldable spare tail unit integrated with the primary empennage, which is extended in emergency situations. Deflection of this spare tail is designed to generate an additional pitching moment, thereby providing a measure of pitch control for the aircraft. Both the primary and spare tail surfaces utilize the NACA0012 airfoil. The Spalart-Allmaras turbulence model was selected for the simulations, which were conducted at a freestream Mach number of 0.6. Computational Fluid Dynamics (CFD) simulations, employing a dynamic mesh technique, were performed to analyze the aerodynamic behavior of the tail system during an elevator jamming scenario. The results indicate that the deployment and appropriate deflection of the spare tail can generate sufficient additional pitching moment, effectively mitigating the loss-of-control problem resulting from an elevator malfunction.