Dr. Day started as an engineer with General Electric in 1960. He was responsible for the High Temperature Turbine Technology Program and managed GE’s business with EPRI and the US Department of Energy.
In 1979 Dr. Day joined United Technologies. He negotiated the contract with the People’s Republic of China that launched the FT8 gas turbine and directed the development of the FT8. He negotiated the contract with Siemens for the joint development of the V84.3A gas turbine and managed that development effort for UTC.
In 1995, Dr. Day led the founding of the Gas Turbine Association, the trade association for the gas turbine industry. He was Chairman of the Board of GTA from its founding until his retirement from United Technologies in 2002.
In 2002 Dr. Day founded Longview Energy Associates, LLC, a technical services company in the energy field with emphasis on gas turbines. Also in 2002 he joined the management team for the University Turbine Systems Program funded by the US Department of Energy, initially through Clemson University and then in 2010 with Leonardo Technologies, Inc., a site support contractor for DOE.
In 2008, Dr. Day also became Managing Director of the Gas Turbine Association.