When an commercial airplane encounters turbulence, how much actual verticle movement is involved? As a nervous flier, a “bumpy” flight sometimes feels like we’re jumping up and down ten or twenty feet at a time, but I wonder if normal turbulance is in reality any more severe than driving on a bumpy road.
Is it all a mental thing, or is turbulence really a whole lot of ups and downs?
Next time you fly, don’t buckle up. If you hit turbulence, rest assured you’ll probably hit the ceiling, meaning the aircraft jumped/dived at least six to ten feet. 
Seriously, aircraft are designed today to withstand stress and turbulence way beyond the human body’s stress levels. I remember some cable TV program about the flex in a 747’s wings - a magnitude around 20 feet! (Or more?)
Jumping 10 or 20 feet is not unusual for light turbulance. It can be much more for more severe turbulance. Severity, though, is more appropriately measured using acceleration. The vertical acceleration associated with light turbulance is quite comparable to a bumpy road, but the airplane does mover farther with each bump.
I’ve been on a transatlantic flight before where when we first hit turbulence, several people came out of their seats… no warning or anything. Another great factor was that it was during dinnertime, and my tray was levitating until I caught it. We experienced ups and downs and ups and… you get the idea… for about 45 minutes, and we had to have been dropping about 20-30 feet at a time, minimum. That’s “light” turbulence? I’m very scared to experience the heavy stuff. Are we talking Castaway here or what?
Just as a disclaimer, I’m 22, but I’ve been doing translatlantics since I was 3, probably about 20 or so. This was BY FAR the worst turbulence I’d ever experienced. We were on one of the new 777s, the ones that just have two massively enormous 10 foot tall engines, one on each side. I kept imagining what would happen if one of those things fell off…