Create a new model for your Tricopter and use the standard airplane template. I believe it defaults to the last model or mode used.
What firmware are you using? Have you updated it since buying the 9xr?
Have I updated it since buying the 9xr? No, I have tried creating a new model but it will not let me change out of the Heli mode. Any one want to buy a Tricopter and radio before I run it through my shredder?????????....
The 9xr has the advantage of a built-in programming port. I suggest that you upgrade the firmware to ER9x or OpenTX. These are much better firmware and there are a lot of tutorials and help available. I didn't have the original firmware on my 9x to become too familiar with it, or become frustrated with it.
But don't worry about changing the mode first. Create the model, and in the settings for the model choose airplane or acro.
There are 9xr forums out there. Try forum.turnigy9xr.com. They may be able to help you with the original firmware.
But I just downloaded the manual and it is not much different than the update.
After creating the model, advance to menu 11, Templates, and choose number 1, Simple 6 channel.