There are Part time bases at bases other than PSM and PDK but they are on a 9 day on 19 off where PSM and PDK are 8 on and 20 off. The difference is because 98% of the time the outstations pilots have to airline to start and end their rotation whereas PSM only airlines 5% of the time and PDK about 20%. For the outstations if you do fly a PC12 on Day 0 (the 1st day of the 9 day rotation) you will get overtime pay.