United Technologies Corp., through its operating segments,manufactures, installs & services elevators and escalators;manufactures commercial & residential heating, ventilating & airconditioning systems; produces commercial, general aviation & military aircraft engines, and military & commercial helicopters; & supplies transport helicopters. Otis manufactures, sells & installs elevators, escalators, automated people movers & service. Carrier manufactures heating, ventilating & air conditioning systems & equipment, & commercial and transport refrigeration equipment. Pratt & Whitney produces aircraft engines, parts, industrial gas turbines & space propulsion. Flight Systems manufactures helicopters,& sells aircraft power generation and management systems, engine & flight controls, auxiliary power units,environmental control systems & propeller systems, air compressors, metering devices, fluid handling equipment & enclosed gear drives.