Taken last week aboard a BA 772 around an hour into flight somewhere over Iguasus falls. Suggest you fast forward to about 4.45 for the start of the heavy stuff.
http://www.youtube.com/watch?v=7UO-wYpNN0s
Interesting to hear the Captain come on and apologise for how rough the ride was.
http://www.youtube.com/watch?v=7UO-wYpNN0s
Interesting to hear the Captain come on and apologise for how rough the ride was.