Two lines: depreciation & amortization, and aircraft rent.

If I'm wrong in my assumption here and it sounds like mansplaining, i apologize.

So in financial statements, you can't use the entire purchase price of fixed assets (stuff you don't sell, this is stuff you use to generate profit, like planes, buildings, large machines, etc.) at once in your financial statements. There are rules for how you can put these on your financial statements (because those purchases take down how much you need to pay in taxes), and the process of how you expense them on that statement is called depreciation (physical assets) and amortization (non-physical assets like trademarks and copyrights, apps, etc.) This is generally done over time, with number of years and amount per year being determined by what you are depreciating or Amortizing

Planes aren't a cost. If you spend $100 million in cash for a $100 million plane, your total assets are still at $100 million. However, planes depreciate over time, which is a cost. When that $100 million plane depreciates so it's only worth $90 million, that $10 million drop in value from depreciation is a cost.

For any rented planes, they'd be accounted for in the 'aircraft rent' category.

They go on the balance sheet, and you depreciate them over time