Wayne I have a few ideas about this problem. Let's start from the beginning.
If you have one of these then we have to figure out how to route the new vent tubing through it. This is the aft interior piece from Flightline interiors. It cover the entire upper part of the aft bulkhead.

Here is an approx spot where the hole will go through the aft bulkhead.

Here is where the hole will go on the interior piece.

The problem is this interior piece must be remove during annual to access the tail cone to visually inspect the area. A possible fix would be to add another AN fitting on the aft bulkhead so you could simple put a hole though the interior piece and remove the vent tubing to remove the interior piece when you do the annual. Here is an approx rendering of a side view of how the vent line would be installed with the new AN fitting.

So Wayne and others out there with this same problem what do you think?
