Without knowing more it sounds like CAT. I remember a long while ago climbing out of AMS in a KLM 767 en route to BEY and just as the crew were released we literally fell into a hole in the sky. The skipper was quick to seat the crew but save for the initial drop, which I can only describe as having the floor fall away under your feet, we just flew on into perfectly still air. Scary stuff and all our crew were lucky that day. I later chatted with the skipper (pre 9/11, sigh) and he told me it was clear air turbulence, unforcasted and undetectable by the wx radar.
Last edited by reverserunlocked; 8th Sep 2012 at 19:18.