| crs_120E | Asia-centred coordinate reference system | 
| crs_Atlantic | Atlantic-centred coordinate reference system | 
| crs_longlat | Lat-long coordinate reference system | 
| crs_N | Arctic-centred coordinate reference system | 
| crs_Pacific | Pacific-centred coordinate reference system | 
| crs_S | Antarctic-centred coordinate reference system | 
| find_leg | Find best non-stop route between 2 airports | 
| find_route | Find best route between 2 airports | 
| find_routes | Find best routes between airport-pair & aircraft combinations | 
| GridLat-class | A grid and lattice combination | 
| hm_clean_cache | Clean the route and SID-STAR cache. | 
| hm_get_test | Get test data | 
| hm_load_cache | Load route and SID/STAR cache | 
| hm_save_cache | Save route and SID/STAR cache to file | 
| mach_kph | Speed of sound, for Mach to km conversion | 
| make_aircraft | Make aircraft data from minimum dataset | 
| make_airports | Make or load airport data | 
| make_AP2 | Make airport-pair dataset | 
| make_route_envelope | Make range-constrained envelope between 2 airports | 
| make_route_grid | Make lat-long grid for route finding | 
| map_routes | Map a set of routes | 
| profile_routes | Profile a set of routes | 
| st_window | Version of 'st_transform' with view window to avoid dateline | 
| summarise_routes | Summarise a set of routes |