United Technologies Corporation is engaged in providing high technology products and services to the building systems and aerospace industries around the world. The Company operates through four segments: Otis; UTC Climate, Controls & Security; Pratt & Whitney, and UTC Aerospace Systems. Otis operates as an elevator and escalator manufacturing, installation and service company. UTC Climate, Controls & Security segment is engaged in providing heating, ventilating, air conditioning (HVAC) and refrigeration solutions. The Pratt & Whitney segment supplies aircraft engines for the commercial, military, business jet and general aviation markets. Pratt & Whitney segment provides fleet management services and aftermarket maintenance, repair and overhaul services. The UTC Aerospace Systems segment provides aerospace products and aftermarket service solutions for aircraft manufacturers, airlines, regional, business and general aviation markets, military, space and undersea operations.