You bring up an interesting data point. American has 17 billion in total debt.

Delta has 9.4 billion in adjusted net debt.

American was able to put up better profit numbers while servicing a little less than twice the debt Delta has.

It is considered unwise actually to carry the amount of cash American has. (Think the beach boys my northern bros) It has a better use than sitting in a bank. If they paid down 8 billion in debt tomorrow and carried the remainder in cash they have almost identical debt and cash on hand numbers to Delta.

They have some integration costs to consider though going forward. That being said, they are able to generate incredible revenue even still.

They will be a strong number one for some time.