Skyhawk 172/Cutlass 172
Flight Crew Commercial; Flight Crew Multiengine; Flight Crew Instrument; Flight Crew Flight Instructor
Flight Crew Last 90 Days 203; Flight Crew Total 875; Flight Crew Type 350
Situational Awareness; Troubleshooting
Aircraft Equipment Problem Critical; Airspace Violation All Types; Deviation / Discrepancy - Procedural FAR; Deviation / Discrepancy - Procedural Published Material / Policy
Flight Crew Landed As Precaution; Flight Crew Returned To Departure Airport; General Flight Cancelled / Delayed; General Maintenance Action
Human Factors; Aircraft; Procedure
During a training flight with a student we experienced an electrical failure/fault with our ammeter indicating a discharge. My student and I flew to another airport 50 NM away from our home airport for a night flight to satisfy PPL (Private Pilot) training requirements. We preflighted the aircraft and all systems were operational. Our runup was uneventful with normal indications and the ammeter showed an appropriate charge indication. We completed two full stop taxi-back landings at the other airport and departed back towards our home airport. About 25 minutes from our destination we heard an odd feedback in the headset and noticed the ammeter was ticking and indicating a discharge. We attempted to cycle the master switch/alternator switch but that did not remedy the situation. We heard the radio start to sound garbled as well. I elected to discontinue the training flight and head back to our home airport where the airplane could be serviced. However; due to the discharging battery; I turned off all electrical equipment in the aircraft including navigation lights and ADS-B out to conserve power so that we could put the landing light and navigation lights on during our approach and landing. This resulted in us not having ADS-B out or navigation lights on in airspace in which they are normally required. I felt it necessary to deviate from the regulations in order to safely get the aircraft back into our home airport where repairs could be made. I also avoided known busy airspace so as to deconflict from any other traffic in the area. We landed uneventfully and the plane was squawked so that it can be inspected.
Flight Instructor reported returning to home airport with NAV lights and ADS-B off after an alternator failure.