A study on the extraction of KT-1 takeoff/landing performance was conducted through the development of the simulation program, which was validated by flight test. Longitudinal 3 DOF equations of motion were solved in conjunction with the modeling of aerodynamics, thrust, landing gear dynamics, control scheme, etc. to simulate the Kr-i trajectories and attitudes during takeoff/landing flight tests. In flight tests, the takeoff/landing trajectories were measured using grid and kinetheodolite tracking method and the grid method was shown to be very useful to measure the trajectories even though very simple. The simulated takeoff/landing distances at test conditions showed little discrepancy as compared to those of flight tests and the simulated control surface displacements, angle of attack, pitch attitude, acceleration also showed good agreements with test data.