David Hartzell has been named president and chief executive officer of Mack Defense, three years after joining the Mack Trucks subsidiary.

Hartzell joined Mack Trucks in 1988 as a staff engineer. He was named chief engineer for electrical and electronic engineering in 1998, before becoming director of product planning in 2003 and director of product development in 2005. In 2015 he became the director of engineering for Mack Defense and was named senior director of product development, purchasing and projects last year.

Hartzell has a bachelor’s degree in electrical engineering from Penn State University. He is headquartered in Allentown, Pennsylvania. Mack Defense, a wholly owned subsidiary of Mack Trucks, is responsible for the sale of heavy-duty trucks to federal- and ministerial-level customers globally.