Ok, I was able to enable the DLC and the game started as it should three times. I suspect whatever the issue was has now cleared itself. Thanks for the help.

I was able to insert a helo and but a few of the options (such as changing seats in the helo) prompted me to have to buy the DLC. Plus the "LSHIFT+P" promo is in the corner of the screen.

Not using the DLC is OK for the moment. I already purchased the DLC but I have not enabled it in my steam properties for fear that I will have the same issue (purchasing it is what caused the issues in the first place).

Was there an issue with the DLC that has since been fixed by a patch -- since the first release on Nov. 4? Has this issue happened to other players?

So, I deleted my entire steam install and re-installed without the Heli DLC and it seems to be working now. I am uneasy about enabling the Heli DLC now but I guess I can live without it. At least it seems to be working again now. I have uploaded the RPT from yesterday evening. I hope that helps. Thanks.