Can you imagine having to drive long distances in a car, train, or bus? Airplane travel changed all that, making travel much quicker, easier, and less stressful. This book addresses the four factors that make it possible for an airplane to fly: weight, lift, thrust, and drag, and details what each of these things means to maintain the safety of the passengers who fly on the over 64 million flights a year in the United States. So, buckle up and enjoy your flight in this wonderful book about airplanes! This book will allow students to ask questions, make observations, and gather information about a situation people want to change to define a simple problem that can be solved through the development of a new or improved object or tool.