Complex sentence: Federal funding for a new tower fell through in both 1993 and 1997, but in 1999 the FAA announced they were restarting the Roanoke project, paving the way for its construction.
Split into simpler sentences: Federal funding for a new tower fell through in 1993 and again in 1997. In 1999 however, the FAA announced that they were restarting the Roanoke project, paving the way for its construction.