What are the chances of being able to branching Aviation from Accelerated OCS?

SPC (Join to see) .. You'll have check with the OCS Cadre/State Personnel G1 on that one. When I graduated from OCS, we could choose any Branch we wanted- all the units/branches came by to give their pitch. If there are 2LT slots, then they'll probably accept you.

I attended federal OCS in 2009/2010. Then, the only way you branched AV, EN, or MS guaranteed was if you had some type of experience (Enlisted MOS) in either CMF and submitted a request on a 4187, and then it had to be approved, or not. Then again, when I was picked up in 2009, I was Active Duty and was DA Assigned EN Branch.

If you’re staying National Guard, it is entirely up to the state. Get ahold of whoever manages that in your state. I know in my flight school class we had more National Guard officers than Regular Amry officers. If going active duty, you might want to call Aviation Branch and talk to them. Aviation is highly competitive and as I understand the process now you rank the branch assignments you want, but then the branch gets a say as to whether or not they want you.