Simplify the following text for a Grade 8 native English-speaking person.
Original: Walters was initially fined US$ 4,000 for violations under U. S. Federal Aviation Regulations , including operating an aircraft within an airport traffic area `` without establishing and maintaining two-way communications with the control tower . ''
Simplified: At first , Walters was fined US$ 4,000 for breaking U. S. Federal Aviation Regulations .