How a Heavy Aircraft Stays Up

Transcript

A passenger aircraft stays airborne because its wing meets moving air..

As the wing moves forward, its surfaces turn airflow, creating an upward reaction called lift..

Its shape can also make pressure lower above than below, helping push it upward, but that is not the whole explanation..

Four forces then interact: lift upward, weight downward, thrust forward, and drag backward..

Weight includes aircraft, fuel, passengers, and cargo, while gravity pulls it toward Earth..

Jet engines expel hot gas backwards, producing thrust that keeps air flowing over the wing..

In steady level flight, lift balances weight and thrust balances drag, so speed stays constant..

Change one force, and the aircraft accelerates or climbs: weight never vanishes, the balance keeps changing..