So would the restrictions be done by nation, airport, or globally all at once? I ask because restrictions in the less economically advanced parts of the world are far less stringent than those in the western world which gives older aircraft a second chance at flying. And on that note, are there any plans to re-work the aging system in the game? Because a lot of aircraft being retired that should have at least another decade of service left. It wasn't unrealistic to find a 45 year old DC-3 or DC-4 still running in South America or Africa in the 1990s and even 2000s, the current model of maintenance costs make that impossible, not to mention the age cap. I just ran a 727-100 to the max age of 35 in DoTM, and outside of the unrealistically expensive maint costs for C and D-checks, the plane turned a profit until the very end. I think that a re-work of the maintenance costs and the max age would allow some of these older liners to see some use in the less economically advanced parts of the world once they can’t fly in the west.
I would also suggest the removal of the price floor for an aircraft once it hits a certain age, if my 727 hits 20 years old it will be near impossible to sell for 15mil, but if it is still economically viable and I can mark it low enough, maybe older aircraft will have an actual market for a change.