If The Drag Of An Airplane Is Equal To The Thrust Of The Power Plant In Straight And Level Flight, What Makes The Airplane Go Forward?

the thrust equals drag formula you are quoting is incomplete. Thrust equals drag at a specific speed. Aerodynamic drag reduces with a reduction in speed. Thus at lower speeds thrust is greater than drag and the aircraft accelerates. When thrust and drag are equal then the aircraft stabilizes at that speed. If you were to dive the plane to gain a greater speed than the trust being exerted would allow then when you lost the additional force of gravity by leveling off the plane would decelerate to that speed where the thrust and drag were equal. It is the thrust that keeps the plane moving forward in level flight. It is the drag that stops the plane from going faster and faster as you continue to input energy into the system with the engine.

comment made by AmyL 8 months ago    Report