A formation
The sky appears blue due to Rayleigh scattering, where shorter blue wavelengths of light are scattered more than other colors by molecules in the Earth's atmosphere. This scattering effect is present regardless of whether airplanes are flying or not. Airplane contrails can contribute to haze under certain atmospheric conditions, but they are not the primary reason for the sky's blue color.
Airplanes were built for flying and transportation purposes.
They fly.
Flying in airplanes: up to scratch idea
In 1903.
there is bob flying one and bill
The sky
safety service
1920
Flying in airplanes... He takes the train...
In the sky, you can see clouds, the sun, the moon, stars, and sometimes airplanes.