Was there not a case, >30 years ago, over the Pacific, perhaps SE Asia, where a BA crew (?) who had astro nav knowledge helped a lost light a/c? It was lost and searching for land, and via a Q&A session about sun angles & relative direction the hi-level crew managed to calculate a circle of probability and suggested a steer to nearest airport and thus within range of a beacon ir sight of land? Memories fading fast, but there is always someone who remembers these things.