“…An important part of an autopilot is the control of an aircraft's longitudinal dynamics, and the most puzzling work of longitudinal autopilot is the automatic landing task. Many control researchers have developed several methodologies to achieve auto-landing flight control design, including PID (Ebrahimi and Coleman, 2001; Ha and Kim, 2005;Iiguni and Akiyoshi, 1998), LQR (Kim, et al, 2005), intelligent control (Iiguni and Akiyoshi, 1998), neural networks (Izadi, et al, 2003;Jorgenson and Schley, 1990;Juang and Cheng, 2001;Saini and Balakrishnan, 1997), fuzzy logic (Nho and Agarwal, 2000), and H∞ synthesis (Kaminer and Khargonekar, 1990;Li, et al, 2004;Niewoehner and Kaminer, 1996;Ochi and Kanai, 1999;Shue and Agarwal, 1999). Some of the designs of auto-landing used classical control techniques; these are the stability augmentation of the inner loop and the path tracking of the outer loop (Kaminer and Khargonekar, 1990;Jorgenson and Schley, 1990;Iiguni and Akiyoshi, 1998).…”