"The IRS uses a number of tests to determine whether or not somebody is an independent contractor. Do you negotiate with each student about the rate that they will pay, or does the flight school set the rate for instruction?
Flight School does. Does the student pay you directly, or does the flight school collect the money and pass it to you?
Passed to me. Do you get the full amount that the student is charged for instruction, or does the flight school get some of it?
The school does... Do you have your own insurance, or does the flight school provide it?
My own 
Would your boss object if you also instructed at another FBO at the same field?
Yep. Big problem if I did. (If so you are definitely not an independent contractor. Come to think of it, if you have a boss, you are not an independent contractor.) If a student shows up with his own airplane, and wants instruction for an instrument or commercial rating, does your boss want some of the money from the instruction?
No question. Do you show up at work in the morning and find a new student on your schedule that you didn't know about?
Ha. All the time. (You are probably an employee.) Did you negotiate with the FBO about your hourly rate, or all instructors of a given level paid the same?
The same..."
Sounds like I'm one of those getting screwed huh?