Airborne Tumbler

Spot I used to farm this, was "How to Train Your Protodrake" world quest. Lots of players in a small area using their dragons to carry protodrakes to the quest spot. Pretty easy to park on a cliff and dive in for the dismount.

For when you need an achievement to know a feature exists.

I obtained this by doing several things:

1. PvP World Quests: find a ledge high up, keep your vigor up/full, wait for people to fly away, then dive bomb them from above like the Red Baron of olde...
2. War Chests: follow them when Malicia announces it, get as high as possible early on. try to come in on people following the long drop routes. Also, dont engage with a large group of the opposite faction, but do wait on a ledge above the chest and try to pick off the last few players coming in to grab the chest.

Have fun, one of the funner achieves.

P.S. Cat druids and pallys are no fun to drop to their deaths though :)