A single-blade propeller may be used on aircraft to generate thrust. Normally propellers are multi-blades but the simplicity of a single-blade propeller fits well on motorized gliders, because it permits the design of a smaller aperture of the glider fuselage for retraction of the power plant. The counterbalanced teetering mono-blade propeller generates fewer vibrations than conventional multi-blade configurations.^{[citation needed]} Often, single blade propeller configurations are touted as having a much greater efficiency than multi-blade propellers, but this is a falsehood outside the inertial losses in spinning a heavier propeller, and the minimal additional drag from added blades.^{[citation needed]} Single bladed propellers are principally used to fulfill engineering requirements that fall outside the scope of efficiency.