Sailplanes are planes without engines that fly by using air currents and thermals.
Sailplanes are often used for sport and recreation, and they are very graceful and quiet in the air.
Examples:
The sailplane glided silently through the sky.
She enjoys flying sailplanes on the weekends.
The pilot landed the sailplane smoothly on the grass.
The sailplane looked like a bird as it soared through the clouds.
The sailplane stayed in the air for hours without using any fuel.
I saw a beautiful white sailplane flying over the mountains.