“…To show the effectiveness of the proposed controller, all simulations following the auto-landing commands should meet the following conditions and scenarios: (i) the time constant ( ) and the flare initiation height (h 0 ) must be pre-determined in Table I, and the values of and h 0 are 2.98 s and 18.47 ft, respectively; (ii) the UAV is trimmed at a speed of 70 knots/altitude of 200 ft and the initial distance is 4000 ft away from touchdown point; (iii) the glide-slope mode is engaged from 3816 ft (H 0 / tan( GS )) away from touchdown point depending on the initial altitude (H = 200 ft) and the desired glide-slope angle; (iv) the elevator actuator is modeled as a first-order system model with a time constant of 0.1 s with a rate limit of 60 • /s, and the throttle servo is ignored; (v) the parameters K 1 , K 2 , and K 3 are easily obtained from (49), and K 1 = 1.5, K 2 = 2.3, and K 3 = 8.0 are selected in the simulations with j ( j= p,i, ,q, f,v,a,d) = 20; (vi) although tracking flight path angle is suitable for varying descent line by using a different glide-slope angle before final approach, a single glide-slope trajectory is used in all simulations; (vii) the successful landing specifications are given in Table II. Note that these specifications are referred to [6,15,33]. Iiguni and Akiyoshi [6] offered the specifications of successful touchdown for transport aircraft, Shue and Agarwal [15] proposed some constrains of the glide-slope maneuver and the bound of the flare maneuver at the landing angle, and Pashikar et al [33] presented the Pill Box conditions for touchdown; any deviation from these constrains, the aircraft will be request to abort the landing task.…”