Researches of Unmanned Aerial Vehicles (UAV) are very topical. A relative implementation success of UAVs resulted during execution of military tasks has expedited the migration of this technology to the civil field. A huge commercial potential of small to medium size UAVs, the monetary value involved along with the relative cheap acquisition price have set new horizons for miniature UAVs development. Recently, the UAVs are used to deliver small/light-weighted consumables, food, to participate in cinematography, to monitor car traffic or perimeters, to perform photogrammetry and rescue tasks. Improving the UAV flight safety and quality is regarded as up-to date scientific and technical discourse. Moreover, subjects such as UAV aerodynamic modeling, path planning, semi and fully autonomous flight realization and control are frequently explored. Nevertheless, the desired outcome in terms of simulations, mathematical models or autonomous real-time flight control regarding UAVs has not yet been reached. In this paper, the authors participate in this worldwide tendency to study the stability of a micro UAV. Unconventionally, and in order to obtain optimal stability criterion, the authors represent the micro-UAV as water drop resisting surface tension forces are applied on it. The developed cost function will be used as a reference to stabilize the quadrotor using linear quadratic regulators.