As a major airline just leased 50 new a380s I thought I'd finally post my thoughts on one of the main reasons this game gets stale and the same few airlines always win. The ability to continually lease new planes plus the first 4 months being free are the main reason these games get dull.
First, it allows you to expand extremely rapidly by earning what in many cases is double the eventual revenue a plane will earn once the lease kicks in. This creates a growth curve that you must stay on to be competitive and makes such a huge difference that it is practically the sole factor in determining how well you will do. Falling of this growth curve for any reason, be it to add a new fleet type, buy an aircraft, or anything other than leasing a new plane will cause you to fall behind.
Second, he 4 month window gives the illusion that certain routes are profitable when they are in fact not, or barely so, which only hurts new or less experienced players at the start of games. Many players don't make the connection between the sudden downturn of their airline and the fact that all their aircraft are out of the 4 month free money stage.
Third, the ability to lease brand new aircraft needs to be limited in some way. A player can lease 20+ brand new planes for the price of purchasing 1 and be guaranteed a steady stream of planes solely for the sake of ordering them. But as long as you receive a new plane at least once every 4 months you will be swimming in money with nothing better to do than order even more planes. The only time its really worth it to purchase an aircraft is when you have spare money floating around and get bored.
Every game follows the same pattern over and over again because of the nature of leasing aircraft in the game. If players were incentivized to actually purchase aircraft, then orders would actually require some strategy to work and fleet planning would be a real part of the game. Leasing does allow for very fast growth, which is exciting and fun, but as it is now the growth is simply too fast and leads to very boring second halves of game worlds.
I propose two solutions to this issue.
1) Eliminate the ability to lease new aircraft entirely, but add in game leasing companies that will order new aircraft and lease them to players at market prices. This solution is the best in my opinion, but also the most radical. It allows for players to still lease new planes while also making the used market more worthwhile.
2) Create an administrative 'fee' that grows exponentially with each leased aircraft. This allows young airlines to grow rapidly, but will eventually become an unbearable cost if you try to build an entire airline on leased planes.
That's enough for now... comments? am I solving a problem most people don't think exists?