The last time I was on a airplane was when I was traveling to Florida for vacation. I wondered how almost 200 people and the mass of the plane didn't weigh the plane down. The forces on the airplane is at equilibrium when the airplane reaches at a certain altitude. Additional when the airplane reaches at a constant velocity therefore the forces on it all must be balanced. This means that the lift force (L) generated by the airplane wings must equal the airplane weight (W), and the thrust force (T) generated by the airplane engines must equal the drag force (D) caused by air resistance. The airplanes wings and the fins in the back of the air plane, cuts down on drag force and increases the lift of force when the plane is increases its altitude. The wings and fins makes the airplane aerodynamic letting the airplane go faster when its flying in the air.