Every now and then, we abandon trains and talk about something different, then by the end of the episode everyone gets to see how much the episode has actually been about trains the whole time. This is one of those times. The crash in 1989 of IDN 1851 is one of the aviation disasters that most grimly highlights how successive small factors can overlay to result in unavoidable calamity. It is critical to understanding systemic, widespread effects right down to seemingly innocuous human errors and their relationship to each other and to safety outcomes. It also happened on my birthday. So it's a worthy episode (in all senses) for us to look at and consider in some detail. Enjoyed this? Please do consider supporting #Railnatter at https://patreon.com/garethdennis or throw loose change at me via https://paypal.me/garethdennis. Merch at https://garethdennis.co.uk/merch. Join in the discussion at https://garethdennis.co.uk/discord.