AerCap is the second-largest aircraft lessor after General Electric 's GE Capital Aviation Services, which begets substantial economies of scale. It's the only independent aircraft lessor with investment-grade credit ratings from all three major credit rating agencies, which enables it to finance its fleet less expensively than competing lessors and operators. (The company recently issued a eight-year bond with a 3.5% coupon, evidence of its financial strength and low leverage profile.)