On 10 May 2016, the Air Force posted online an amendment to its Air Force One contract authorizing Boeing to begin preliminary design activities. The latest version of the contract synopsis confirmed that the government will buy two modified 747-8 aircraft. Boeing was awarded a contract in January 2016 to identify cost reduction opportunities in areas including maintenance, aerial refueling and communications. On 15 July 2016, Boeing received another contract for pre-engineering and manufacturing development (EMD) risk-reduction to address "system specification, the environmental control system, the aircraft interior, the electrical and power system and sustainment and maintenance approaches" to reduce development risks and life-cycle costs.