United Technologies Corporation provides technology products and services to the building systems and aerospace industries worldwide. Its Otis segment designs and manufactures escalators, moving walkways, and passenger and freight elevators. The company's Carrier segment offers residential, commercial, and industrial HVAC and refrigeration systems and equipment; food service equipment; building automation and controls; and HVAC and refrigeration components, as well as provides retrofit and aftermarket services. Its UTC Fire & Security segment provides fire and special hazard detection and suppression systems, fire fighting equipment, electronic security, monitoring, and rapid response systems and service, as well as offers security personnel services. The company's Pratt & Whitney segment supplies aircraft engines for the commercial, military, business jet, and general aviation markets; industrial gas turbines; space propulsion systems; and spare parts, as well as provides fleet management services, and maintenance, repair, and overhaul services. United Technologies' Hamilton Sundstrand segment offers aerospace products, including power generation, management and distribution systems, flight systems, engine control systems, environmental control systems, fire protection and detection systems, auxiliary power units, propeller systems, and industrial products, such as air compressors, metering pumps, and fluid handling equipment. This segment also provides aftermarket services, such as spare parts, overhaul and repair, engineering and technical support, and fleet maintenance programs. Its Sikorsky segment manufactures military and commercial helicopters, as well as provides aftermarket helicopter and aircraft parts and services. In addition, the company develops geothermal power systems and fuel cell power plants for stationary, transportation, space, and defense applications. United Technologies Corporation was founded in 1934 and is based in Hartford, Connecticut.