E-8A Original platform configuration.[30] TE-8A Single aircraft with mission equipment removed, used for flight crew training.[30] YE-8B Single aircraft, was to be a U.S. Navy E-6 but transferred to the U.S. Air Force as a development aircraft before it was decided to convert second-hand Boeing 707s (1 from a Boeing CC-137) for the JSTARS role. E-8C Production Joint Stars platform configuration[30] converted from second-hand Boeing 707s (1 from a CC-137).