FabrikaCr/iStock via Getty Images AerCap (NYSE:AER) is the largest aircraft leasing company in the world. It had more airplanes than Delta and Southwest combined! The company owns more commercial aircraft than the largest, and far better-known, individual carriers. In fact, some of the airplanes flown by the big US carriers are leased from AER. AER owns or controls more than 2,000 commercial airline aircraft - plus more than 150 cargo planes, helicopters, and other aircraft types -- and more than 1,000 airl ...