From past experience, I can tell you the certification process will take about a year, and that is if all is in order. The DOT is very careful in giving their approval now a days after what happened to some of these fly by night operators that recently went bust. The DOT is concerned with the background of corporate managment of which they now conduct thorough checks. The FAA also is in no rush in putting together a CSET team together for certification either since their budget is quite limited too.