With an increase in demand for high performance UAV (Unmanned Aerial Vehicles) for various demanding applications such as defense, search and rescue and weather monitoring, the design and production of the UAVs is of prime importance and with the UAVs comprising of many complex systems, the reliability of each system decides the reliability of the overall aircraft. One of the UAV’s critical components is its landing gear. High stiffness and lightweight are the main design criteria for the landing gear. Apart from the fatigue cycles, the propagation of crack in the landing gear structure due to the fatigue loading is also another important criterion for the design of the landing gear structure. This study is conducted using the Structural analysis available in ANSYS R15.0 using Mechanical APDL solver. In this paper, the authors have studied the effect of contours and crack length on variation of stress intensity factor for different modes and fatigue crack propagation rate. Static analysis is performed to locate the position of critical region. The variation of J Integral is studied for different contours along the crack front. The crack propagation rate was found to increase with the increase in crack length. The critical stress intensity factor is evaluated using modified Paris Law referred to as Forman Law.