At the start of the game, no one's selling & no one's quitting. It can sometimes take a few game-years before the used market starts to show anything. If a player is inactive for 5 game-years, they get shut down. So it's usually at least 5 - 10 years before any large quantities of aircraft show up.
Keep in mind when a player quits the game with leased aircraft, I don't think those aircraft go to the used market necessarily.
True but at the same time not. I sell the first aircraft I get (usually a 737 or an A320) around 3 months after starting once I get the budget to buy the aircraft as I will switch to 757s due to its higher capacity meaning less slots are used (reducing the chance of filling up the whole terminal of 200 gates.
Also, I noticed that aircraft that you sell only goes on the market the next month or sometimes two months later.
I usually come into games part-way through. I have, for the first time, joined a game at the start.
When do used aircraft come on to the market please?
Do you have to wait until they are sold by an existing airliner, or are a certain number added at the start of a game please?
You might be referring to the sandbox worlds where 5 aircraft of each kind available at that time goes on the used aircraft markets. They appear every hour at around the 7th to 8th minute just for your information. The maximum number of each kind that can appear is 65-75 before the oldest batch of that aircraft gets taken out of the market.