General Electric is the world's largest maker of jet engines, so if you've ever been to an airport, you've doubtless heard the whine of GE jet engines. Keeping all those engines functioning is the task of GE Engine Services. The company provides engine maintenance, repair, overhaul services, and technology upgrades, as well as engine exchange. It supplies customers with new and used engine parts; leases engines and provides financing for engine customers; and inspects, analyzes, and diagnoses engines. Not only does it work on its own engines, but it also works on its competitors' engines, including those made by Rolls-Royce and Pratt & Whitney.