Your best bet would be to look in the AscTec Pelican stack. This quadrotor has a functional urdf file that can be used to bring up the pelican in Gazebo. I don't believe that the urdf provided functions 100% in Gazebo yet, so here is a link to my previous resolution of this issue.
Originally posted by DimitriProsser with karma: 11163 on 2011-11-22
This answer was ACCEPTED on the original site
Post score: 3
Original comments
Comment by DimitriProsser on 2011-12-05:
I've still been unable to solve this problem. The one advantage is that with this configuration, you can create your own quadrotor mesh and load it in place of the pelican's mesh and it should still work.
Comment by DimitriProsser on 2011-11-23:
The .stl file is indeed incorrect in some way. I'm not exactly sure why/how this happened, but I reproduced your error exactly. The odd part is that it looks perfectly fine in Rviz. I'll look into this.
Comment by tfoote on 2012-03-19:
You can also check out the hector quadrotor stack recently released. http://www.ros.org/news/2012/03/announcement-of-hector-quadrotor-stack.html documentation http://www.ros.org/wiki/hector_quadrotor