Planetary gearboxes are a mechanical devices consisting of multiple gears arranged in a circular configuration around a central sun gear. This layout enables an efficient gearbox with high torque in a compact design, thus making it well-suited for a wide range of industrial and military applications such as industrial motors, rotorcraft, vehicles, wind turbines, and more. However, when it comes to aircraft applications, weight and strength are essential considerations in the design process. Genetic algorithms are used to optimize the parameters of a single-stage planetary gearbox in order to achieve the necessary balance between weight, strength, and performance in aircraft applications. The study focuses on formulating the optimization problem in an appropriate way while also developing constraints that guarantee the effective functioning of the planetary gearbox. In order to effectively address this complex and multimodal constrained optimization problem, this paper suggests utilizing an enhanced genetic algorithm (NSGA-II), which is widely recognized as the most commonly employed evolutionary optimization technique. In comparison with conventional GA algorithm, the numerical simulation results demonstrate that the suggested method exhibits enhanced optimization performance in relation to the quality of the achieved solutions.