Small Aircraft; High Wing; 1 Eng; Fixed Gear
Flight Crew Private
Flight Crew Last 90 Days 32; Flight Crew Total 231; Flight Crew Type 220
Human-Machine Interface; Situational Awareness
Conflict NMAC; Deviation / Discrepancy - Procedural Other / Unknown
General None Reported / Taken
Human Factors
On a flight from ZZZ to MPR; I flew a practice approach into MPR (RNAV 18) visually in VFR conditions with no view limiting device. As I was touching down on Runway 18 at MPR; I observed another aircraft taking off from the grass Runway 8. The other aircraft crossed in front of me about 400 feet ahead of me and was about 100 feet above me and climbing. I had made a number of radio calls including a 10 mile straight-in final; 5 mile final; 2 mile final and short final. I never heard the other aircraft make any calls. Upon landing; I realized that although I had plugged the MPR CTAF frequency into my radio; I never flipped that frequency to active. Therefore; I had been transmitting on and listening to the incorrect frequency (departure Tower frequency). I take full responsibility for not having the correct frequency active in my radio and will use this as a learning opportunity and a reminder to be more vigilant about confirming proper frequencies. I am surprised that the ZZZ Tower did not hear my 10 mile; 5 mile; 2 mile and short final calls and inform me that I was on the incorrect frequency.
Pilot reported landing after broadcasting on the wrong CTAF frequency for MPR airport resulting in a conflict with another aircraft taking off on a crossing runway.