expanded to the United States in 2001, locating its U.S. headquarters in Herndon, Virginia. It operates in 50 cities across 23 states. It was known as VT Systems (VTS; formerly known as Vision Technologies Systems) until 1 July 2019, when VTS was changed to ST Engineering North America as part of the Group’s brand harmonization exercise in 2018. As of 28 February 2022, Temasek Holdings has a 51.69% shares in ST Engineering. Core capabilities ST Engineering's businesses span across the aerospace, smart city, defence and public security sectors. Aerospace ST Engineering Aerospace provides provides nose-to-tail lifecycle solutions including aviation asset management to commercial airlines, airfreight operators and military operators. It is the world's largest airframe maintenance, repair, and operations (MRO) company, and one of the few with in-house engineering design and development capabilities. On top of MRO capabilities, ST Engineering also has expertise as an OEM specialising in engine nacelle and composite panels. It is the only company in the world offering Airbus freighter conversions using OEM data. Smart City ST Engineering's technologies and solutions in Smart City addresses the connectivity, mobility, security, infrastructure and environmental needs of cities. Its solutions span over rail and road, autonomous and electric vehicles, mobility payment systems, building access and security systems, as well as IoT solutions for lighting, water and energy management. Its Smart City business has a track record of 700 smart city products in over 130 cities worldwide. In March 2022, ST Engineering completed its acquisition of Transcore to enhance its Smart City solutions through TransCore’s market leading end-to-end tolling solutions and congestion pricing businesses. Defence & Public Security ST Engineering's defence business provides integrated defence technologies and critical systems spanning the digital, air, land and sea domains. It has over four decades of expertise in the development of military technology and solutions, from aircraft and avionics Avionics upgrades, to designing and building proven battlefield mobility platforms, soldier systems, ammunition and naval vessels. Its solutions in Public Security cover critical infrastructure, intelligence operations, homeland security applications and maritime system, which have been implemented in more than 100 cities worldwide. Controversy In 2014, ST Engineering and its subsidiaries ST Engineering Marine and ST Engineering Aerospace were hit by one of the largest corruption scandals in Singapore history following investigations by the Corrupt Practices Investigation Bureau. In December 2014, former ST Engineering Marine and ST Engineering Aerospace president, Chang Cheow Teck, was charged