[Moonman62]

I was on a plane that landed so hard that some of the oxygen masks came down along with a couple of ceiling panels, but nothing like that from turbulence.

I notice on Flightaware that commercial airliners avoid moderate to heavy precipitation when they can. For this particular flight there was no precipitation along the route.

http://flightaware.com/live/flight/UAL1676/history/20140217/1815Z/KDEN/KBIL

[Lockbar]

In ‘93 was on a flight from L.V. to Chicago, hit clear air Turb that was so bad it damaged the plane. People were really screaming. Pilot couldn't deploy the flaps on desent so they had to declare and emergency and was coming in fast. You know its bad when fire trucks are at the side of the runway waiting for you. Took me a couple of years before I resumed flying.