I am embarrased sharing this but maybe it will help someone. I have an Inspire 1 D model with about 4.7 hours on it. I guess I have not been doing my preflight inspections very well or this just happened on the last flight (which I doubt). At least it was found before a failure. I brought it inside and felt a little movement on the left arm and looked at the mounting screws. Much to my surprise there were only 2 out of the 8 screws still attached. This could have been a catastrophic failure. I will certainly pay more attention in the future.