You have to think of it in terms of a house mortgage. You, the borrower, borrow money to buy a house from DoucheBank. DoucheBank lends you the money, as long as they are put as first lien holder on the paperwork. DoucheBank can also use this same practice on high dollar items, such as aircraft. This is standard practice in the industry, nothing really suspicious.
There are certain places in airline parts warehouses where the shelves will say 'ALL ITEMS CONTAINED HEREIN PROPERTY OF DOUCHEBANK' . These are typically engine parts, as it is a regular practice to rent them to airlines.