After viewing @DeerCrusher’s post on possible range notifications, I figured that it would also be necessary to add a critical aspect of range - ETOPS. ETOPS, short for Extended Operations, is a classification and certification given to aircraft that wish to fly over water far from land, and once certified, allows aircraft to fly a certain distance away from an airport in a given number of minutes on one engine. No aircraft is allowed to take a route that is farther from a suitable diversion airport than it is certified to land at, and thus would be where this feature would apply.
A ring or circle around all suitable diversion airports would be applied based on an aircraft’s certification (ie. an 777 with EIS of ETOPS-120 would have a different sized circle around its diversion-capable fields than an A350 with ETOPS-370 capability).
Additionally, this could also be extended to work with DeerCrusher’s range idea, where based on weather data (ie. winds, jet stream, etc.) the size of applicable circles would change based on the range of the aircraft and be a physical reminder of the range that an aircraft had available. Circles could be dynamic and change based on the amount of fuel/payload onboard, and thus could give an estimate of where the aircraft was able to fly.
This idea can be altered, and if necessary, be modified to include things like airline/aircraft-specific certifications (ie. a Delta 777-200ER would have a different circle size than a British Airways 777-200ER because it was certified to ETOPS-180 vs the BA’s ETOPS-120). Additionally, this could also be altered to only show circles based on the start and end airports one picked (ie. transatlantic flights could only show circles going over North/South Atlantic tracks rather than showing all circles available). This is a very dynamic idea, and could be an additional overlay like the terrain overlay that can be turned on/off. As Global approaches, it seems as if proper flight planning based on things like ETOPS would be interesting to add as to enhance the realism of IF.
An example of this possibility is shown below, with circles around airports. This is obviously not to size, yet still a good visual aid in this example. As seen below, it is clear that one could not fly outside of the range circles and must (or at least should) file a flight plan within the circle.