DA 40 flight Instructor and student pilot reported experiencing alternator issues while executing a missed approach resulting in the flight crew returning to the airport where they landed safely.
Synopsis
DA 40 flight Instructor and student pilot reported experiencing alternator issues while executing a missed approach resulting in the flight crew returning to the airport where they landed safely.
Narrative
Flying alternate missed instructions up to 4000 on runway heading out of ZZZ after a practice approach. The low-volt annunciation came on; and we pulled out the QRH shortly after the coolant temperature was high. I took control and turned us back toward ZZZ and advised ATC that we were headed back for landing due to alternator failure. I had guessed that the belt powering both the alternator and water pump had broken (although the alternator fail annunciation never came on); so we reduced power and maintained altitude in preparation for an engine failure. When we called the tower and told them we were coming back in for immediate landing on XX they said it wasn't the active runway; so at that point I requested priority handling. Meanwhile; every annunciation indicating an overheating engine was going off; and we had a dual ECU (Engine Control Unit) fail (the engine stayed on). I realized I was very high and began a forward slip with full flaps. This wasn't enough; so I did a left 360 and; after leveling off; decided to join the left downwind for XY; remaining high. I pulled power after turning final and was able to glide down to the runway and taxi to the ramp without further assistance. After the engine shut down; the marshal told us a belt was hanging from the bottom of the plane.
Second reporter narrative
Shot the RNAV XX into ZZZ; and were planning to do a touch and go; then depart southbound. We completed the touch and go; got back on with approach; who instructed us to climb to 4000 and cleared us direct ZZZ1 (the next airport we were planning to go to). Somewhere around 2800 feet I noticed a low volts indication. I handed controls over to my instructor who started a turn back towards the airport while I looked in the QRH. Whilst turning back towards ZZZ; low coolant and high oil temp annunciations came on amongst other things. At this point we contacted tower and told them we needed to land runway XY (which was opposite traffic at the time). They responded saying that runway XX was in use; which is when we requested priority handling. We were too high to make XY; and after a left 360; we determined the best action would be to join a left pattern for XX; which we did and landed safely. My CFI flew this portion of the flight and did a great job. After landing we exited the plane and noticed the alternator belt hanging out behind the nose wheel.
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.