First, your brother should check all the terms and conditions of his probation as there mayt be a specific restriction imposed upon his depending on the nature and facts of his case. However, in general, any such request of someone on felony formal probation must get approval from his probation officer.
In order to ensure that your brother does not violate his probation, he needs ask his probation officer first. If the probation officer says ok, then you should be good.
However, depending on the nature of the request, the probation officer may say your brother needs to approval of the court in which case your brother should contact his lawyer to put the matter on calendar in order to obtain the court's approval. Also, try to get the probation officer to submit a report indicating that they are ok with your brother going out of state as the judge will most certainly want the approval of probation in making its decision.
The bottom line ...your brother should only follow what the probation department and/or court says he can do.
I hope this was helpful.
A probationer needs the approval of his probation officer to travel outside the state for any reason. If the probation officer will not approve the travel, the probationer can petition the court to order it approved. The probationer will need to contact an attorney to petition the court if this is the case.
If your brother is on formal probation (where he has to report to a probation officer) then he must advise his probation officer of the situation, including your desire to leave to Alaska, and obtain the PO's authorization. Otherwise, he will need to petition the court. Hope this helps and good luck.