Delta Air Lines Route Map for the US & Canada : r/MapPorn
India Air Routes network Map, Air Routes network Map
Open-source airline route maps from 1999 and 2018 created using Python and BTS data (see corresponding comment for clarifications + GitHub link) [OC] : r/dataisbeautiful
Airline Route Map Images – Browse 13,340 Stock Photos, Vectors, and Video | Adobe Stock
Route Map | PSA Airlines
The Design History of Airline Flight Maps - Bloomberg
FlightConnections - All flights worldwide on a map!