We are a Corporate/ Part 135 company, 1 turbo-prop, 2 pilot operation (insurance requires 2 pilots) and average 25-30 hours. The duty sheet I keep for the FAA, I also note all duty time spent in the office, RONs, On-call days, and true scheduled rest days, etc. I have tried to argue for a third trained and checked pilot, but the owners don't see that as an option. We get contract pilots with advance notice with a pilot on time-off. If we don't have the back-up, we don't fly. We fly 300 hr a year, 400 would be ideal - at least as far as aircraft utilization. Over that you are on a busy schedule where you better hope you have no office obligations or aircraft cleaning chores (or Part 135 obligations). With 1 aircraft, you also need at least 90% dispatch reliability for hours approaching 500 hrs/yr (very little breaks and quick inspections)- which means an in-house maintenance facility.