Answers Beginner's Guide to Aerodynamics Cruising Aircraft and Balanced Forces Answers Answers will vary. Suggested answers shown below. Force is a push or pull in a specific direction. The four forces acting on an airplane are lift, weight, drag, and thrust. Lift pushes or pulls the airplane up.
Weight pulls the airplane down towards earth.
Drag pulls the airplane back to keep it from moving forward. And thrust pushes the airplane forward. Define balanced and unbalanced. Balanced means everything is equal. Unbalanced means not everything is equal.