If the mother has temporary custody and gets a felony drug charge does the dad get custody?

Has Mom been convicted of the drug charge yet? If she has been convicted and has or is going to be sentenced to jail time, then the father should get sole custody unless he has other prior convictions for things that would imply a danger to children. In that case the court might ask DHS to place the child or children with a foster home for a while. Generally, the natural parents have the top priority for getting custody. If they are both living a normal life without accusations of criminal or abusive behavior, then the Court should determine who gets sole custody based on the best interest of the child. Once the Court determines which parent should get sole custody, the other parent is entitled to parenting time, usually based on a Standard Parenting Plan adopted by the local court.