Date: 202202
Local time of day: 1201-1800
Location: ZZZ.Airport, US
Flight conditions: VMC
Weather elements / visibility: 10
Light: Daylight
Aircraft: Bonanza 33
Operator: Personal
Operating under: Part 91
Flight plan: IFR
Mission: Personal
Flight phase: Cruise
Airspace: Class D ZZZ; Class E ZZZ
ATC / advisory: TRACON ZZZ
Aircraft component: Electrical Power
Component problem: Malfunctioning
Reporter organization: Personal
Reporter function: Pilot Flying; Single Pilot
Reporter qualification: Flight Crew Private; Flight Crew Instrument
Human factors: Distraction; Situational Awareness; Time Pressure; Troubleshooting; Workload
Anomaly: Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural Published Material / Policy; Flight Deck / Cabin / Aircraft Event Smoke / Fire / Fumes / Odor
Detector: Person Flight Crew
When detected: In-flight
Result: Air Traffic Control Provided Assistance; Flight Crew Requested ATC Assistance / Clarification; Flight Crew Returned To Departure Airport; Flight Crew Landed in Emergency Condition
Contributing factors: Aircraft
Primary problem: Aircraft

Narrative: This was the first flight after significant maintenance work on the field at ZZZ; with my autopilot and my turn coordinator both acting up. The shop replaced an autopilot servo and the turn coordinator and returned the plane to service on Date.I did an especially thorough pre-flight and run up but everything checked out. I added a pint of engine oil supplement after a recent oil change during pre-flight. The new turn coordinator worked in taxi and the autopilot worked on the ground. I filed IFR to ZZZ1 and back for a shakeout cruise and proceeded as planned.Approach asked if I was planning approaches at ZZZ1 and I told them I was just doing the shakeout flight; so flying around would be fine. Approach gave me vectors west as I ran through flows; making sure things looked good in the autopilot.About 5 minutes into the flight as I leveled out at 4;000 ft; I heard an alarm or alert and the standby alternator light was activated. I smelled hot electrical smell or smoke and started troubleshooting the primary alternator. There wasn't that much load to shed; but I turned off running lights and strobes and I cycled the alternator on and off. When I turned it off; the alarm or feedback through my headset went away; it came back on when I flipped the primary back on. I cycled it a few times; and the sound eventually faded.I asked to return to ZZZ and soon after [requested priority handling] with Approach. The electrical smell was still there; but wasn't getting worse. Approach asked me about my gear and I was able to deploy it; but I should have waited until closer to the field. Still; once they were down and I had three green lights indicated; the gear was staying down.Approach passed me back to Tower; which cleared me for landing on [Runway] XX Right. I asked for and got [Runway] XX Left; because it was closer to parking but also the nearest runway to me. Tower confirmed gear down and I landed uneventfully. About 50 yards down from my tie-down; a pilot was watching me come in and said he smelled the plane but neither of us smelled smoke after I shut down; so probably something electrical.I'll put the plane back in for maintenance to look at next week; with particular focus on the voltage regulator; alternator and battery.Reviewing the flight and areas of improvement; I should have [requested priority handling] more forcefully. I made the right decision to return to ZZZ to land; it was as close as other options and has services on the field. I also dropped the gear too far out; worried that I wouldn't have power to get them down otherwise -- I should have maintained the slicker plane and dropped the gear closer to landing; as usual.




Synopsis: BE-33 pilot reported electrical smoke in the cockpit during cruise flight. The aircraft had recently been in maintenance servicing the autopilot and turn coordinator. The pilot reported returning to the origin airport.