a) Beacon inop Strobes good. Fly or not? b) Strobes inop Beacon good. Fly or not? c) Beacon inop No strobes. Fly or not? Looking for a better reasoning/understanding in these scenarios. My personal understanding is that if any installed anti-collision lighting (beacon/strobe) is inop then the plane is grounded. So, situation (c) is grounded for sure. But (a) or (b)?