Which is a reasonable explanation for why airplanes cannot fly in the mesosphere? the water vapor and dust particles in mesosphere could foul an airplane’s engines. to fly, airplanes need lift provided by air currents, and there is not enough air in the mesosphere to provide this lift. to fly safely, airplanes need to avoid extremes of weather like those encountered in the mesosphere. the mesosphere is too close to the earth, and airplanes flying there would run the risk of crashing into objects like mountains.