You probably know the feeling all too well. Moments after takeoff, after the landing gear finishes retracting, the plane begins to shake. You grip the armrests, you palms become sweaty, you feel the tension, you start to look around frantically, and you may even look out the window to see the wings shudder a bit. Maybe the airliner flew into a thunderstorm, maybe there are unexpected jolts in the middle of a calm flight, or maybe you feel some rocking and swaying right before landing. Whatever the case may be, you have experienced a routine, yet one of the most feared parts of the flight: turbulence.
The air above ground is usually not in a perfect and calm stream. There are winds, jet streams, storms, heat, and cold waves, and of course the effects of mountains and other geographical features. This causes the air to become unsteady and in cases such as clear air turbulence, unpredictable. When aircraft fly through this kind of air, it may experience shaking, swaying, vertical movement, and vibrations. In almost all cases, this is a routine part of a flight and not in any way dangerous to the aircraft, the crew, or any of the passengers, as long as they keep their seatbelts fastened.
Modern airliners are extremely safe and rugged. They can handle pretty much any kind of turbulence that is thrown at it without much happening to it. Even though it may seem like there is chaos at times during the worst jolts and bumps, the reality is that everything is under control. People naturally fear what they cannot see, control, or most of the time understand. Looking out the window, you might notice wings flexing and moving. This is normal, and actually by design. Large flexible objects tend to handle stresses better than rigid structures. Aircraft wings, fuselage, and other parts are designed, heavily tested, and proven to withstand large forces and fluctuations. In reality, there is nothing to fear from a technical standpoint.
To fully enjoy your journey, you must also enjoy the flight. One way to do that is to remember that turbulence is normal, not dangerous, sometimes annoying, and that all aircraft are safe and well built. The pilots and flight crew are usually not bothered, and the seatbelt sign is actually there to help prevent you and other objects from flying within the cabin. The turbulence will pass, and the aircraft will land safely at the destination. Sit back, relax, and enjoy the flight. It is a solid piece of advice that might give you some piece of mind that you will hear at the end of the flight safety videos.