I've had this problem several times before so I'll just post this one case.

I was editing the trifighter_chunk1 msh trying to delete all of the edges until I had just the missile left. Most of the edges I could select and delete. But there were a few edges that could not be deleted. Does anyone know what is wrong here?

Try alt+delete instead, you should delete polygons instead of edges so you won't run into these problems.

I'm guessing that you're using RepSharpshooter's Msh Importer utility, when you import the obj file produced by this utility the first thing you should do is select it and weld everything with a tolerance of .001 , then you can select entire parts with the Polygon Island selection filter in just 1 click then extract delete them into separate objects.

Sweet that worked like a charm. And I will do that next time. Thanks!