airAX Air Services T7-AIRX Beechcraft King Air 250 T7-AIRX for the HTAI model.
These are textures only.
The HTAI Beechcraft King Air B200 model is required.
It can be found at http://htai-models.com/downloads.html
The converted P3Dv4 model can be found here:
https://www.alpha-india.net/forums/index.php?topic=26276
Flightplans available here: https://www.alpha-india.net/forums/index.php?msg=413074