Is there a financial benefit from acquiring aircraft using your line of credit?
Well, getting them more quickly means they can be earning money more quickly. That usually easily outweighs the cost of the loan, so long as you actually have work for them. Be careful of your cashflow though. If you can't meet the loan payments there will be penalties to your company image and over-stretching your cash is the easiest way to go bankrupt at the start of a game.
In general though, I ALWAYS max-out my loans for the first few years of the game as growth is exponential, so any head start you can get will benefit you later.
Try to use a secured loan if you can as the rates are lower. There is a nice little 'hack' to be had there, but I'll let you work it out for yourself.
I think it's also worth mentioning in comparison to leasing as well. I think that is useful context for whether a loan is worth it to buy as well.
Having done some rough calculations on several aircraft.
Scenario 1 - Lease vs Buy (No loan) - You will find that point between total lease payments reaching what it would have cost to buy the aircraft outright initially and rising above is broadly speaking around the 6.5 year to 7 year mark.
Scenario 2 - Lease vs Buy (Loan for 100% aircraft cost, 6 yr repayment, AAA rating. So best rating, lowest interest, longest repayment time) - I've tended to find that the cross over between total leasing costs incurred vs the total loan cost to acquire outright cross over around 8 years or so.
When I have roughly worked these out, little bit of rounding and assuming no discounts on either the leasing or purchase price. I assume, the rough cross over points won't change massively with whatever discounts you get. It also appears that these points stay broadly in line with each other regardless of aircraft price.
Now, none of these take into the fact, if you scrap or sell the aircraft, you are going to get something back. Basically, I'm assuming the aircraft is basically worthless whenever you are finished with it. But yes, you will get some equity back if you sell or scrap the aircraft and this does benefit you.
Worth saying with loan costs, your breakeven point will probably vary if you credit line is not AAA rating (so more interest and expensive) or you repay faster (less interest and less total expense). These calculations have been done with the 2.2% plus margin rates currently found in my world, which a relatively low. Higher rates will move this breakeven point later.
None of this is particular hard to work out. It's just PURCHASE PRICE/YEARLY LEASE COST = Crossover point or TOTAL LOAN COST/YEAR LEASE COST = Crossover point.
And to add to the above post, leasing over loaning/buying is definitely worth it when you have limited capital and cashflow to buy aircraft consistently for required expansion. So worth considering the "opportunity cost" between the two.
Equally, loans to flush out your cash capital to buy is perfectly good as a strategy. Especially if it meaningfully allows you to do something faster, bigger more discounted order or just have more owned assets in the long run. Equally, if a loan is available and your cash flow can support it, loans to get a decent number of aircraft loan prepayments down to allow consistent delivery slots for expansion, especially when you are small and looking to grow, can equally be worth it. When buying, I tend to loan to cover the delivery payments, more as a preference that anything. You may choose to do things differently.
Cash Flow Statement is probably the most important thing you should refer to, or at least should be used in conjunction with you profit/loss statement if you are considering loaning.