Featured Map for 7 April 2023:
Air21

Air21 was an airline based at Fresno that was founded in January 1994 and lasted until January 1997. They operated a fleet of five Fokker F28s with seating for 64 passengers.

A few days ago, Departed Flights shared a route map for Air21 generated using the Great Circle Mapper using data from their schedule for 4 March 1996. The map used geodesic paths, which for Air21's short routes are nearly straight lines, plus it creates an ugly crossing of the FAT-LAX and SFO-PSP routes. This is the sort of map for which the new Bézier paths were created.

Today's Featured Map recreates Air21's 4 March 1996 route map using Bézier paths. All but one of the paths use a Bézier configuration of 25%@-30°, which places the first control point for each segment 30 degrees to the left of the geodesic path at 25% of the path distance. The second control point is 30 degrees to the right of the reverse path. How these paths are plotted depends upon the ordering, e.g., FAT-SFO won't be drawn the same as SFO-FAT. Careful tinkering with the order allowed a single Bézier configuration for almost all of the map.

The exception was the path from Palm Springs to San Francisco, which uses a more extreme configuation (50%@-80°) in order to avoid crossing paths.

References and additional information:

• Facebook: Air 21 (A7) March 4, 1996 route map... – Departed Flights (Facebook group) (1 April 2023)
• Departed Flights
  • Air 21 March 4, 1996 System Timetable
  • Air 21 March 4, 1996 Route Map
• Air21 – Wikipedia
  
  
• Featured Map: Introducing Bézier Paths (24 March 2023)