I am currently running LMS 3.2. When I open Chassis View for a 6509 switch and click help there is a link for CatQDM. The help page does not say how to open CatQDM from the Chassis View page.
The CatQdm feature is only available for Cat6500s running CatOS. You can launch it by right-clicking on the chassis, and selecting CatQDM from the pull-down menu.