The biggest airline in the world is United Airlines, with a fleet size of 1,372 aircraft that flies around 165 million passengers per year. In second is Delta Air Lines, with about 1,300 aircraft and 140 million passengers. But a little known fact is that Wall Street banks own more planes than the world’s top seven airline companies combined, according to current FAA records.

Many of the aircraft that the banks offer out are small, corporate jets that they lease to clients. For example, Banc of America Leasing, a leader in the corporate aircraft market, with a portfolio of more than 750 clients and $7.25 billion in aircraft loans and leases, is the number-one U.S. corporate aircraft financier, according to its website.

Aircraft financing is similar to getting a mortgage or an automobile loan. Necessary credit checks are performed and an appraisal is conducted on the aircraft’s value. Background checks are done on the aircraft’s registration number to ensure it’s clear of liens or title defects. On the other hand, commercial planes are hugely expensive. For example, the Boeing 737-700 that forms the bulk of the fleet of Southwest Airlines is priced from $58.5 to $69.5 million, so financing it involves more sophisticated, leases and debt-financing schemes. Clearly, the easiest and cheapest type of sale is in cash, yet few airlines rely on that considering orders can amount to hundreds of aircraft and billions of dollars.

The most common form of purchase for large airliners is direct lending that has the same rules as buying a car or a home: If you don’t make a payment, the bank will repossess. Usually, only established carriers with high equity and steady cash flow are eligible for this type of financing.

Less common is finance leasing, which means that the operator leases the aircraft for a set amount of time and then can choose to purchase at the end of the lease. And finally, there's operating leasing, which is good for startup airlines that can lease for a short term (normally 10 years) or for established carriers that are experiencing a shortfall or wish to expand and test new routes.

Banks, because of the nature of the aircraft they own, usually only loan aircraft they own for short leases and one-time trips on what’s called wet leases -- and with those, the lender gets the crew, too.

Banks' plane and helicopter ownership, according to, including corporate jets used for bank business: 

1. Well Fargo & Co (NYSE:WFC): 5778

2. Bank of America (NYSE:BAC): 90

3. JPMorgan (NYSE:JPM): 54

4. PNC Financial Service Group Inc (NYSE:PNC): 23

5. CitiGroup Inc (NYSE:C) (various branches): 21

6. The Bank of New York Mellon Corporation (NYSE:BK): 11

7. Capital One Financial Corp (NYSE:COF): 8

8. SunTrust Banks, Inc. (NYSE:STI): 5

9. U.S. Bancorp (NYSE:USB): 3

10. Morgan Stanley (NYSE:MS): 3