if the drag of an airplane is equal to the thrust of the power plant in straigyt and level flight what makes t

Answer 1

Control altitude with power and speed with pitch is what my flight instructors always said. But that is over simplified, since both affect each other. The point is, if thrust does not exceed drag, the airplane cannot climb.

By the way, there is a special place just for aircraft questions in the cars and transportation section, and this isn't it.

Answer 2

Camp is on a good track for explaining this but he has a couple of terms mixed up. Drag and thrust are opposite forces acting on the plane, each pressing backwards and forwards, respectively. If thrust = 0 and drag = 0, the plane isn't moving. If thrust = 100 and drag = 10, the plane is accelerating. If thrust = 100 and drag = 100, the plane is flying at a constant speed. You question doesn't seem to be about thrust and drag though. You need to be thinking about lift and gravity too. If you have 100 thrust, but zero lift, you are on the ground, going real fast. If you have 100 thrustand lift that is greater than the weight of the plane(due to gravity), you will rise.

The end result is that you can't think about a plane without having all 4 forces acting at the same time. Thrust and Drag, Gravity and Lift. I hope this gives you a better understanding of how this works.