The purpose of this paper is to analyze the flight stability of an Unmanned Aerial Vehicles (UAV) formation by using a 3 degrees of freedom (3 DOF) models. The problem of flight formation will be approached in a simple manner, by using a 3 DOF nonlinear models, as well as using a linear. This theoretical development allows us to build stability matrix, command matrix and control matrix and finally to analyze the stability of automation flight of the UAV formation. The work will present and analyze the calculus results for developed solution. The novelty of the paper consists in algorithms that allow evaluating the stability for the UAV formation. The results will focus on fly stability of a UAV formation and his answer to regular perturbations.