Millions of people fly in airplanes every year, but few know what takes place behind the scenes to ensure the flight is ready for travel. During an airplane turnaround, the plane is cleaned, cargo is unloaded and loaded, and a maintenance check is performed. A precise amount of fuel is calculated and added depending on flight times, weather conditions, and how much weight is on the plane. Pilots have specifications on how long they can fly and if they are fit for flight, and passengers are not allowed to board the airplane after the door is closed. On your next flight, take a moment to appreciate all the hard work people put in to ensure your flight happens.