I fly part 91 and part 135. I'm based at airport A. Our customer charters our company to fly him from Airport B to Airport C. My company says that the empty flight from A to B must be operated under 135. The flight from B to C is 135, BUT the empty flight from C back to A (homebase) can be operated under Part 91. Is this legal? Is it more complicated--i.e. more information required. I've "heard" that it depends on what exactly the customer has paid for. For example if he is charged for the empty flight from C to A, it is 135, but if that flight is on my company's dime, then it can be a 91 flight.