Yes, i know, but it doesn't work so in reallity, if a aircraft is certified one day, it can be delivered to airlines next day.
You're right and you're wrong.
You're right that it can
be delivered to customers the next day. Theoretically. If there were no other orders to produce.
But in reality, there's already other lines in the production queue ahead of you. The A340-600 doesn't get its own
production line, it's produced right along with all the other A330/340s. So if there's a few hundred -300s in the queue ahead, sorry, you're not getting your -600 for a while.
In real-life, the A330/340 has a production queue of about 600 aircraft. It produces the family at a rate of 8.5/month, let's round up and say 100 a year. So if you were to buy a new Airbus 330/340 today you could wait as long as 6 years
to have it arrive. This is of course barring any changes in their production schedule, efficiency increases, or new production facilities.
There's also the exception for the launch customer. The launch customer can elect, and usually does, to purchase the first few production units of a model that are used for certification or manufacturing/logistics/flight testing, etc. These units are inserted into the queue, basically they cut in line, otherwise Airbus would have to wait years to certify its own plane while it waited to get build, so delivery can be taken at roughly around the time of certification. But that's only a very finite number of planes.
Virgin Atlantic placed their orders for A340-600s in 2002 as the launch customer -- they got 4 very quickly, as soon as it was certified, the rest trickle in as they get through the production queue. Of a total order of 20 they've only received 14 in the past 7 years. It'll be at least a decade
between the time they placed their order until they received it all. And they were the launch customer, and there's only a handful of A340s left to produce (only orders for 20 more to make, that's it), but they're still taking a while due to length of the A330 queue.
The driving factory in the difference between reality and this game in this particular circumstance, is that, by the time a manufacturer is rolling out a new variant of a model, they're usually doing it because the queue of the previous model was drying up. And often times even buyers of the older variant can 'upgrade' to the new one to expedite the lowering of that queue and phase in the newer version. That doesn't happen here. A new model can come out even while the existing one has a decade-long production queue. That would be unlikely to happen in real-life. After certification of the -500/-600 variants of the A340 for example, only a relative handful of -300s were produced, because the queue was relatively small. If it did happen where there was such a long queue, you can bet that they would alter production to suit -- manufacturers like long queues, but not too
long -- it scares away customers and makes production of new variants difficult. Airbus, for example, was set to give production of 330/340 a hefty bump to help clear out the queues for A350 production, but the downturn in the economy killed that plan.