After 6887 hours in a flight simulator toying with VATSIM in an old A2A Boeing 377 plus the regular trips to the cockpit of real life Airbus 320’s and also piloted airplanes myself, I believe I gained some knowledge about turbulence and flying Airplanes. Yes, I am abusing Cialdini’s authority principle on purpose.
You should always wear your seatbelt during flights. This story is pretty self-explanatory when you consider the link in the bottom of this post.
Turbulence, or “air holes” can force an airplane to drop several 100 feet (aproximately 33 meters), VERYVERY quickly, when the airplane looses lift due to low pressure zones, gravity takes over and accelerates the plane brutally downwards at 9,82m/s/s – remaining lift as we are not in a vacuum. This can be very brutal, if you are not wearing a seatbelt, the airplane will plummet away under YOU unless you are wearing a seatbelt to keep you in your seat.. That means you will take off from your seat (fly in the air), bump your head on the ceiling and injure your neck and spine. When Lift is restored, (higher air pressure) the forces will switch dramatically. The airplane will stop dropping, but now it is your turn to drop back down into your seat. (Brutally)
Always remain seated with seatbelt on! Even if it is uncomfortable. It is not cool to refuse to wear it even though you might think it is.