I have an add on helicopter in my game its an Augusta Westland LSPD and LSFD helicopter. I'm looking for help making it so that it spawns in as my Air Support and or EMS heli backup in UB.

Hey there......a fellow Canuck!  

I haven't done it for awhile now, but in your UB folder - check out the "DefaultRegions.xml", and the "SpecialUnits.xml".

In DefaultRegions, scroll down until you see the section "<LocalAir>".  In there, you should be able to change the name of the helicopter "vehicle" (by default, it is POLMAV, I think) to whatever your addon helo DLC is called, for each area of the map that you want it to respond in (LS City, County, Blaine, and North Yankton).  Should be no different than changing or adding an addon/DLC car to appear those areas, as part of your LSPD or BCSO or whatever fleet.  Either that, or take the DLC pack helo model files, rename those to POLMAV, then drag/drop those in to whichever patch day you use for your replace models.  Those files would then easily overwrite the existing vanilla POLMAV model files, in whatever earlier patchday those are in.

For the EMS helo, it looks like you would need to go in to the "SpecialUnits" xml.  Scroll down to find the section  "SpecialUnit name="Air Ambulance".  Same idea there, I think - change the "Vehicle" name listed to whatever the addon/DLC model name is for the medical helo you want to use.

If they are both the same August Welland model, just with different liveries - that can work too.  Just change the part about "livery=" to show the livery you want for that unit (matching the "sign_xx" livery texture in the .ytd file).

Hope that helps!!  (.......and works, lol)