The "A" fund portion is taxed as ordinary income in the year that your receive it unless you have been declaring the contributions as income.
As long as you declare the income and pay the required tax there is no special method of returning the money to the USA. Just wire it directly to whatever account you want to place it in.
When you leave Emirates they give you a number of options for the Provident Fund money. You can take it as cash (check really) paid on the day you leave; you can have it wired to an account of your choice (which will be done 3-4 weeks after you leave); plus two other choices which I forget (they are on the form though).
Harry, the option to keep it in the Provident Fund is only available if you "retire" from Emirates.
So with $100K, probably $70K is "A" fund taxed at around 33% you'll be writing a check to the IRS for $23,000. It's just wonderful to be an American sometimes
TP