The indefinite-delivery / indefinite-quantity contract requires Boeing to provide programme management, supply chain management, field service representatives, aircraft depot maintenance, and engine maintenance and overhauls.
The work to be undertaken at Oklahoma City, and San Antonio, Texas, is expected to be completed by the end of 2016.
E-4B is a mobile command post operated by the US Air Force for the National Command Authority, which includes the president and the secretary of defence of the country.
The four National Airborne Operations Centres are operated by the 1st Airborne Command and Control Squadron of the 55th Wing at Offutt Air Force Base, near Omaha, Nebraska.
A modification to Boeing 747-200, E-4B is designed to support US command authorities to connect with strategic launch control centres and strike assets during a national emergency.
They protect the crew from electromagnetic radiation and the effects of a nuclear blast.
The aircraft are an upgrade of the previous E-4A. The first B model entered service in January 1980.
The four aircraft carry 13 external communications systems and are designed for missions lasting 72 hours.
The advanced communications infrastructure allows the inmates to communicate securely with other air- and ground-based executive command and control facilities.
The Communications Navigation Surveillance / Air Traffic Management (CNS/ATM) feature enables E-4B to operate efficiently at airports and in crowded airspace.
Image: A E-4B aircraft. Photo: courtesy of Boeing.