Hey people!
This stuff is interesting but it seems to be a little chaotic at the moment... I have a few questions (lazy to look, but it would be handy if we would have it all together here).
First of all, how many aircraft slots are there available in the game? (Hmm, just counted, there's 35 planes in the temperate set, so it's at least that many -- good that gives us a good number to work with)
Second of all, what are all the planes that you're planning to include?
In my opinion, it would be a good idea to create a good mix of passenger and cargo planes. As for the passenger planes, they should be mostly prop and jet planes.
One supersonic is in my opinion enough, since Concorde was the only succesful supersonic passenger jet, and it seems like we won't have anything like it in quite some time. If desireable, a second one could be included as well, maybe with canards, just to differentiate them visually (ala the Sonic Cruiser).
http://www.boeing.com/news/feature/concept/flash.html
Another possible type of plane (albeit futuristic) would be something in the BWB (blended wing body) style.
http://oea.larc.nasa.gov/PAIS/BWB.html
http://www.geocities.com/witewings/bwb/competitors.html
Again, only one or two of those, and they would be introduced most likely around 2020 at the earliest.
As for the passenger jets, it would be handy to have a good choice of regional as well as mid/long distance planes. It would be nice to go for different looking airliners, I think it would be nicer. In my opinion, it isn't really necessary to have the entire Boeing and Airbus lineup, just a good choice out of them.
For example from Airbus, I think A310 (mid range), one of the A32x line (regional), A340 and the A380. Talking about the A380, it could be a good idea to remove that fifth engine from the "Super Jumbo" and turn it into the Airbus. I honestly think noone in their right mind would build a five engine plane (even the tri-jets are fairly rare these days and not very popular, I think). The main advantage that four engines have as opposed to two is getting around the ETOPS limitations.
From the Boeings a similar choice could be made - 737, 747, 777 and 7E7.
I'd guess we can also add the 727, very popular, tri-jet with all three engines at the back.
Now, let's look for some other things to add. I'd guess it's very hard to make a decent selection, since there's so many different planes. I'd guess I'll go mostly with western planes for now.
Fokker 70 or 100 - fairly current regional, two engines at the back.
Either DC-10 or MD-11 would be a good choice too (tri-jets, but two underwing engines).
I'd guess the de Havilland Comet is mandatory, since that's what started the jet age.
BAe 146 could be interesting.
For the props, hmm ATR 42 or 72, DC-3.... to be honest I'm running out of ideas now.
For the transports, somebody mentioned the Mryia (An-225), good idea! Also the Beluga (A300-600ST) and Galaxy (C-5).
It would probably be a good idea to make a comprehensive list of planes, with some info like type (Passenger/Cargo/Both), speed, capacities, year of introduction, type of powerplant.
A good source of images are
http://www.airliners.net and
http://www.jetphotos.net
Hmm, I think I've babbled for long enough, but you do get the point.

It's certainly not a comprehensive list, and I don't claim I really know what I'm talking about

However, I love planes, so I just couldn't keep my mouth shut. I hope this is useful to you guys and that I didn't make too much of an ass out of myself, heheh.
Cheers,
minime
[Edit: Hmm, I'd guess I should have looked at the other topic as well, before writing this think. Well whatever, it's my 2 cents

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