I was driving home from work on Friday night and a plane was flying over me. The lights were so bright! And it started me thinking... what is the purpose of turning on the "headlights" (or whatever they are officially called) on an airplane while it's in flight?
I can easily see the use for them during takeoff and landing. And I get that they need the marker lights so that all the airplanes can see each other in the dark. But why the headlights? Exactly what are they looking at up there?