So now that I've gone away and done most of what I learned in this thread, I thought Id ask another question, this time with loans.
I know that you can secure a loan on an aircraft and get more cash while doing so. I was wondering if its possible to buy outright a small low value aircraft, get a loan on that to buy outright an even larger aircraft and get another loan on that and then continue business as normal with (hopefully) a much larger loan than I would get from just the small aircraft. Is this a good strategy or have I got things completely wrong?
No, not a good strategy. First, the amount of security is approximately the amount of load you can get. So if you use 20 mil aircraft as security, you will only get 20 mil additional secured loan.
Second, and this is a mistake that even experienced players make: buy the first aircraft you can afford, meaning a small aircraft. You should buy only aircraft that you are 100% sure you are going to fly it until the end of its useful life - or aircraft you can readily sell on the used market. If you don't have a good candidate (aircraft), just save your money and wait.
If you look at the used market, and if you see a the aircraft you are considering offered by several brokers - it is probably not a good aircraft to buy. You can lease it at good terms, and it is also an indication that other players don't want to fly that aircraft...
As far as growth strategy based on loans, it is only good strategy when the game world opens, during the initieal frenzy. You can get aircraft quickly and you can secure production slots on new aircraft.
During the middle of the game, growth using borrowing just does not work well in AWS. There is a hard limit on the total loan available ~500 mil, once you hit it, that's it. The loans are only good as a rainy day fund. Loan availability saved a lot of airlines after 9/11. Those that bankrupted probably were tapped out on the loans.