Flight Stability of an Airplane on Mars

We compared the flight stability of an airplane on Mars and on Earth. Two kinds of airplanes were used in our analysis: a centimeter-sized indoor airplane with a very thin and light main wing, and a meter-sized airplane flying outdoors. Our comparisons show the following. (1) A longer period is required to damp or diverge disturbances on Mars than on Earth. (2) On Mars, the added mass and added moment of inertia can be ignored for a light wing, whereas the added mass and added moment of inertia cannot be ignored on Earth. (3) The natural circular frequencies in the short period, the phugoid, and the dutch roll modes are smaller on Mars than on Earth. The reduced frequencies, based on the natural circular frequencies on Mars, are smaller than those on Earth. The smaller reduced frequencies and the smaller added mass and added moment of inertia imply that the significance of unsteady aerodynamic force due to fuselage motion is lower on Mars than that on Earth.