First, the good news: aircraft, alternator and broader electrical system, pilot and passengers are all in perfect condition!

1. Situation

After landing at the home base, the primary alternator (ALT 1) failed and became intermittent during taxi testing.

We needed to address the fault while mitigating the risk of the main battery (BATT 1) failing if the ALT 1 fault persisted.

The maintenance team, located approximately 35 minutes away, was unsure what to bring with them, so we decided to attempt to fly the aircraft to the maintenance base.

2. Task

The task was to develop a plan to get the aircraft to the maintenance base while mitigating the risks associated with a potential BATT 1 failure.

The goal was to avoid a PAN PAN situation or worse and to ensure that BATT 1 could preserve enough power for essential systems like flaps and lights during the approach to the maintenance base if ALT 1 failed in flight.

3. Action

We discussed with the maintenance team to explore all likely causes of the intermittent fault and possible scenarios, resulting in a solid plan.

A friendly and highly experienced instructor reviewed our plan.

We then coordinated with ATC at both the home base and maintenance base, as well as with the halfway point ATC, to ensure everyone was aware of our plan and intended actions for various eventualities.

We executed the plan, prepared to return to the home base if anything unexpected occurred.

4. Result

The departure from the home base was uneventful until the ALT 1 fault reappeared during climb out. BATT 1 voltage remained high (25V), so we continued the flight, relying on ALT 2 and BATT 2 for essential systems while managing BATT 1’s slow drain.

We turned off unnecessary electrical systems such as strobes, landing light, fan, and the 12V armrest socket.

Upon reaching the halfway point, BATT 1 voltage was still high but below 25V, so we agreed with ATC to turn off BATT 1, maintaining radio contact and planning to reconnect it within 10 minutes if contact was lost.

Turning off BATT 1 revealed that COM 1 no longer worked, which was later identified as a separate fault and repaired by maintenance.

We turned BATT 1 back on in preparation for the approach to the maintenance base to ensure flaps and landing light would be available.

We encountered no issues with ATC and switched to the maintenance base approach frequency.

After receiving priority from ATC over circuit traffic, we landed without incident, using full flaps in two careful stages and the landing light.

The call in advance to ATC proved helpful, allowing them to anticipate our needs.

On taxi to the maintenance base, BATT 1 voltage began to drop below 24V, indicating about 30-40 minutes of reserve after the ALT 1 failure, which aligned with expectations.

The aircraft was repaired with a new electrical part (a regulator overloaded by a voltage spike) rather than replacing ALT 1 itself.

The return flight home was uneventful, with all systems functioning perfectly.

How to use this case responsibly

Separate the evidence from the teaching interpretation. First list only what the cited source or scenario actually establishes. Then list the assumptions that would need checking: aircraft variant, installed equipment, weather, runway state, pilot qualification, local procedures and the exact sequence of events. This prevents a memorable story from becoming an invented checklist.

Before the next relevant flight, turn one lesson into a concrete briefing item or decision gate and verify it against the current AFM or POH, official aeronautical information and operator procedures. If the case exposes a skill gap, rehearse it with a qualified instructor under suitable conditions. After the flight, record whether the warning sign appeared, whether the gate was usable and what should change next time.

For a group debrief, ask which decision was last easily reversible, which cue was available at that moment and what pressure encouraged continuation. Compare at least two safer alternatives and identify the new risks each would introduce. The aim is not hindsight blame; it is to build options early enough that the safest action remains practical.