@sorbetua Hi, and thank you for the reply.
Through trial-and-error I discovered that the issue was due to another dlc being installed. If I'm honest I didn't work out which one it was, but after a clean install of the game with no dlc, the little symbol was back in the aircraft. However, after downloading a few dlc the symbol disappeared again.
Ironically, after all that, once I got the symbol to show, I did not find it all that helpful in my navigation. So its subsequent disappearance has not bothered me.
