Navion Aircraft Corp Undifferentiated or Other Model
Flight Crew Instrument; Flight Crew Private
Flight Crew Last 90 Days 42; Flight Crew Total 752; Flight Crew Type 26
Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy
Flight Crew Diverted; Flight Crew Landed in Emergency Condition
Aircraft
While in cruise flight; my airplane's propeller hub lost oil pressure resulting in a max angle blade angle (low RPM) setting; and then I made an unplanned landing at ZZZ. I was on flight following with Approach at the time of the malfunction and informed them that I had 'partial power loss and would be making a landing at ZZZ'. The controller confirmed I was the aircraft only occupant and worked me until I was sure of being able to make the landing; and then handed me off to ZZZ Tower. I was able to make a successful spiraling descent; landing; and then park on the general aviation ramp where I was met by the airport's firetruck to confirm that I was okay. I then called WX Brief to close my flight plan and inform them that I had landed at ZZZ instead of my intended destination; and I requested they confirm that Approach knew I was on the ground safely.
Pilot flying Navion A aircraft reported mechanical failure of propeller governor resulting in low RPM.