Southwest Airlines Co was incorporated in Texas on March 15, 1967. The Company operates Southwest Airlines (Southwest) and AirTran Airways (AirTran), passenger airlines that provide scheduled air transportation in the United States and near-international markets. At December 31, 2013, Southwest's and AirTran's combined active fleet consisted of 680 aircraft, including 614 Boeing 737s and 66 Boeing 717s. Southwest principally provides point-to-point service, rather than the hub-and-spoke service provided by U.S. airlines. The hub-and-spoke system concentrates on airline's operations at a limited number of central hub cities and serves other destinations in the system by providing one-stop or connecting service through a hub. Southwest does not provide international service; however, in April 2013, the Company began converting AirTran service to San Juan, Puerto Rico, into Southwest service, Southwest's first scheduled service outside of the continental United States. Southwest offers inflight satellite-based WiFi service and AirTran currently offers GoGo's inflight internet connectivity on every Air Tran flight. The Company is subject to various federal laws and regulations relating to the protection of the environment, including the Clean Air Act, the Resource Conservation and Recovery Act, the Clean Water Act, the Safe Drinking Water Act, and the Comprehensive Environmental Response, Compensation and Liability Act, as well as state and local laws and regulations.