I've been checking out the different parts for all the Fars and I am a little confused about the commercial parts. I understand that part 119 regards the certification of air carriers and commercial operators...But parts 121, 125, and 135 I don't quite understand. What is confusing me is that I work for a small airline that flys Dash 8's and we can carry up to 37 passengers not including crew, yet the company says we operate under part 121, and the regs says that part 125 is for aircraft that have a seating capacity of 20 or more... So why isn't my company a 125 operation, or for that matter a 135. If anyone is familliar with these parts and has experience with them I sure would appreciate you bringing me up to speed.