C172 pilot and pilot rated passenger reported alternator failure inflight. Diverted and landed uneventfully.
Synopsis
C172 pilot and pilot rated passenger reported alternator failure inflight. Diverted and landed uneventfully.
Narrative
I was the PIC with a rated CFII in the right seat as a passenger VFR night cross country flight (ZZZ1-ZZZ2) in Aircraft X (C172). I first noticed the instrument panel becoming dimmer and dimmer. I immediately looked at the volt/ammeter and it was discharging a low amp/volt indication. After troubleshooting; I had to minimize the cockpit electrical load and emergency brief with my pilot rated passenger. We came to the conclusion that our alternator was no longer charging our battery and there for a complete electrical system failure was imminent. Together; in accordance with safe and proper CRM; I and my pilot rated passenger split the responsibilities. I was solely tasked with flying as PIC the airplane (aviate 1st) and had him handle the diversion airport; radio communication. The best decision was to divert to ZZZ for multiple reasons.1.) Familiar airport by the both of us and its facilities.2.) Safety was key holder here - Temp's were below freezing at the surface and the FBO is open at the time giving us safe shelter. ZZZ is staffed with controllers and ARFF (Airport Rescue and Firefighting).3.) Lighting - ZZZ is controlled; in the event of a complete electrical power loss in flight; landing at an uncontrolled with pilot-controlled lighting would have been an added risk factor if lighting could not be activated by us.Once the decision to divert was made; a call was made to ZZZ Approach on XXX.XX by my passenger and they were notified of our intentions to enter a left downwind for runway XX at ZZZ. The decision to land on XX at the time were favoring the winds from the west and we were anticipating a no flap landing due to our flaps being electrically powered.ZZZ Approach had informed us they have contacted ZZZ1 Approach on XXX.XX1 as well as ZZZ on our behalf; and we were handed off to ZZZ1 Approach on XXX.XX1; then to tower XXX.XX2. By the time we were handed off to tower; our GPS; exterior lighting; flaps; and comm 1 had all failed. My passenger pilot managed to transmit on comm 2 a broken but readable to tower that our plan was to enter a left downwind XX. Tower acknowledged 'clear to land XX' and he repeated back 'clear to land XX'. I flew a standard traffic pattern at pattern altitude with a complete electrical failure. I then got off runway quickly on to taxiway 1 and held short of taxiway 2. I used my personal cell phone to call tower to let them know where our location was because they could not see us. I used my headlamp to flash a light on/off at them. They then saw our location and gave us taxi clearance taxiway 1 to taxiway 3 then to ramp. We were met with ground crew assisting us to park. Completed the shutdown and our flight was completed safely; using CRM and remaining calm throughout with precise intentions.
Second reporter narrative
I was a pilot rated passenger on a VFR night cross country flight (ZZZ1-ZZZ2) in Aircraft X (C172) when we noticed the panel lights in the cockpit were unusually dim. We then observed a discharging amp/low volt indication on our volt/ammeter. After a thorough troubleshoot; minimization of cockpit electrical load; and subsequent emergency checklist brief; we came to the conclusion that our alternator was no longer charging our battery; and therefore a complete electrical system failure was imminent. Together; in accordance with safe and proper CRM; the pilot and I split responsibility between us; Person A was solely tasked with flying the airplane; I was solely tasked with diversion decision and radio communications. The decision was made to divert to ZZZ for three reasons:1) Familiarity - both the pilot flying and I were intimately familiar with the airport and its facilities.2) Safety - temperature was below freezing at the surface and the FBO was open at the time; and ZZZ is fully staffed with controllers and ARFF (Airport Rescue and Firefighting).3) Lighting - because ZZZ is controlled; in the event of a complete electrical power loss in flight landing at an uncontrolled airport with pilot-controlled lighting would have been an added risk factor if lighting could not be activated by us.Once the decision to divert was made; a call was made to ZZZ approach on XXX.XX; and they were notified of our intentions to enter the left-downwind for runway XX at ZZZ. The decision to land on Runway XX from the left-downwind instead of the closer straight-in for XY was made because winds at the time were favoring Runway XX and we were anticipating a no-flap approach to landing due to our flaps being eclectically powered. ZZZ aproach informed us that they had contacted ZZZ1 Approach/ZZZ on our behalf; and we were subsequently handed off to ZZZ1 approach on XXX.XX1; and then to tower XXX.XX2. By the time we were handed off to tower; our GPS; exterior lighting; flaps; and comm 1 had all failed. I managed to transmit a broken; but readable; transmission on comm 2 to tower that we were entering the left-downwind XX; which tower acknowledged by giving us our 'runway XX; cleared to land' clearance. The pilot flying flew a standard pattern; approach; and landing with a complete electrical failure. The pilot then taxied clear of the runway on taxiway 1; and held short of taxiway 2 on 1. We then contacted ZZZ1 Approach via cellphone reception and were able to get the phone number for ZZZ tower. Tower was unable to see our position on the airport surface due to our exterior lighting being inoperative; but the pilot flying was able to signal our position with a personal headlamp that Person A uses for night flights; and through these methods and phone communication tower was able to clear us to the FBO ramp via straight ahead on 1 and right on taxiway 3. A ground crewmember was able to marshal us to our parking; and ARFF was also on scene to meet with us and offer any assistance. The airplane was parked; shut down safely and secured; and we had successfully completed our mission.The actions that were taken by the pilot flying and I to identify the problem; split responsibility; and execute our plan led to a safe and effective outcome that ensured success from the beginning. Thank you.
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.