Wind-driven turbine vent. 1  Wind-driven roof vents will pull more air from the attic, but only when the wind is blowing. 2  Flat roof vents have no moving parts to break or squeak, but don't vent as much air as wind-driven vents.
An airplane or aeroplane (informally plane) is a powered, fixed-wing aircraft that is propelled forward by thrust from a jet engine or propeller. Airplanes come in a variety of sizes, shapes, and wing configurations. The broad spectrum of uses for airplanes includes recreation, transportation of goods and people, military, and research. Commercial aviation is a massive industry involving the flying of tens of thousands of passengers daily on airliners.
Some of these gases are used as lifting gases in lighter-than-air aircraft, which include free balloons, moored balloons, and airships, to make the whole craft, on average, lighter than air. (Heavier-than-air aircraft include airplanes, gliders and helicopters). 1 Usage as lifting gas.