RV-10
Flight Crew Instrument; Flight Crew Private
Flight Crew Last 90 Days 12; Flight Crew Total 800; Flight Crew Type 150
Communication Breakdown
ATC Issue All Types; Aircraft Equipment Problem Less Severe
Flight Crew Diverted; Flight Crew Landed As Precaution
Human Factors; Aircraft
I was on an IFR flight plan. Along the route I began to show low voltage indicating a likely alternator problem. Knowing the engine would continue to run; I advised Center of the problem and that I would likely lose radio communication; and advised that my intentions were to continue on to [destination]. The Controller confirmed that he got my report. Shortly thereafter; I could hear him calling me several times but my radio would not transmit due to the low voltage. Shortly thereafter; I felt the engine began running rough and decided to land at the nearest airport. Immediately upon a safe landing; I called 800-WX-BRIEF to advise. At the same time; someone from the FAA called the airport. I was asked to call the Ops. Mgr at Center; which I immediately did. I explained what happened and why I decided to land; considering it an emergency since I was experiencing engine roughness. [The FAA representative] asked if there was anything that ATC could have done differently. My only suggestion would have been for them to ask me to do something to know if I could still hear them; such as squawk a different code; or turn left or right; or climb or descend. Then if I could still hear them; they could have advised the next frequency that I would have needed to tune to for further instructions.
RV10 pilot reported diverting to an alternate after experiencing loss of communication related to an alternator problem as well as a rough-running engine.