United Technologies Corp. provides products and services to the building systems and aerospace industries worldwide. The company operates through five business segments: Otis, UTC Climate, Controls & Security, Pratt & Whitney, UTC Aerospace Systems, and Sikorsky. The Otis segment designs, manufactures and markets elevators, escalators, moving walkways and service. The UTC Climate, Controls & Security segment provides heating, ventilating, air conditioning and refrigeration solutions, including controls for residential, commercial, industrial and transportation applications. This segment also provides security and fire safety products and services. The Pratt & Whitney segment provides aircraft engines for the commercial, military, business jet and general aviation markets. This segment's commercial engines provide maintenance, repair and overhaul services, including the sale of spare parts, as well as fleet management services for large commercial engines. The UTC Aerospace Systems segment provides aerospace products and aftermarket services for diversified industries worldwide. Its aerospace products include electric power generation, management and distribution systems, flight control systems, engine control systems, intelligence, surveillance and reconnaissance systems, engine components, environmental control systems, fire protection and detection systems, propeller systems, aircraft nacelles, and interior, actuation, landing and electronic systems. The Sikorsky segment manufactures military and commercial helicopters and also provides aftermarket helicopter and aircraft parts and services. This segment's aftermarket business includes spare parts sales, mission equipment, overhaul and repair services, maintenance contracts and logistics support programs for helicopters and other aircraft. United Technologies was founded in 1934 and is headquartered in Hartford, CT.