PC-12
Flight Crew Instrument; Flight Crew Private
Flight Crew Last 90 Days 7; Flight Crew Total 2900; Flight Crew Type 1600
Situational Awareness; Communication Breakdown; Time Pressure
Conflict Ground Conflict; Critical; Ground Incursion Runway
Flight Crew Took Evasive Action
Environment - Non Weather Related; Human Factors
The CTAF frequency was quiet; and I announced that I was taking runway 24 for takeoff. Just before entering the runway; I looked; but did not see any aircraft approaching for either runway. During the takeoff roll; the airport manager noticed another aircraft landing on the opposite runway 6; and alerted me on the CTAF frequency. It was only then that I noticed the aircraft.Fortunately; that aircraft was on the ground and stopping; and I was ready to rotate; which I did; missing the other aircraft on the ground. In speaking to the airport manager later; he informed me that he had spoken to the other pilot; who had said that I wasn't on the frequency. After the airport manager informed him that I was on the frequency; and that it was he that wasn't on the frequency; they checked his radio and discovered that he was indeed on a different frequency by mistake.The lesson learned for me is just to reinforce that seeing approaching aircraft can be quite difficult; especially when they are on final with a cluttered background. Therefore; especially at uncontrolled airports; it is vital to use extra caution to ensure there are no aircraft approaching before entering the runway; and then to focus more than normal attention to such on the takeoff roll as well.
Pilot reported a critical ground conflict with opposite landing aircraft; determined later to be using the wrong CTAF frequency.