Atlas carried the weight of the world; Atlas Air Worldwide Holdings (AAWW) carries the freight of the world. The company leases cargo planes to customers, mainly airlines, under long-term ACMI (aircraft, crew, maintenance, and insurance) contracts. The segment accounts for about 45% of AAWW's revenue. All told, the company maintains a fleet of more than 35 Boeing 747 freighters. AAWW also offers dry leasing (aircraft and engines only) via its Titan division. Affiliates Atlas Air and 51% owned Polar Air Cargo provide charter services to charter brokers, freight forwarders, airlines, and the US military (referred to as AMC) which accounts for 22% of sales.