What is the force of gravity acting downward on an aircraft known as?

The force of gravity acting downward on an aircraft is known as weight. This force is a critical factor in the overall performance and behavior of the aircraft during flight. Weight is the result of the gravitational attraction between the aircraft and the Earth and is directly proportional to the mass of the aircraft. It affects various aspects of flight, including the ability to take off, climb, cruise, and land.

Understanding weight is essential for pilots and aircrew as it helps them calculate loading, balance, and fuel requirements, which are vital for safe flight operations. Other forces like thrust, lift, and drag interact with weight during flight, but they represent different physical phenomena. Thrust is the forward force produced by engines, lift is the upward force that counteracts weight, and drag is the resistance encountered by the aircraft as it moves through the air. Together, these forces dictate the aircraft's ability to fly efficiently.