Many airlines, especially those outside the U.S., lease their aircraft from Leasing companies like Flightlease, ILFC, Boullioun, CIT, GE Capital (GECA), GATX, and others. I think GECA and ILFC are the biggest.
Swissair, for instance does not own a single plane. They are all leased from Flightlease (which happens to be an subsidiary (unconsolidated, I think).
These companies must own thousands upon thousands of aircraft - the value of their balance sheets must be tremendous (1000 planes, average $100 million a piece= $100 billion, ballpark), but you almost never hear of them.
Does anone know where we can get some financial detail on these leasing companies? They don't even have web sites, that I could find.