In December 1979, Boeing delivered the first E-4B Advanced Airborne Command Post to the U.S. Air Force. The E-4B evolved from the earlier E-4A, of which three were built. By 1985, all A models had been upgraded to B models. Based on the 747-200B, the E-4B provides a highly survivable command, control and communications center in case of national emergency, with “nuclear hardening” to withstand the effects of an electromagnetic pulse from a nuclear blast. All E-4Bs are assigned to the 595th Command and Control Group at Offutt Air Force Base, Neb., with at least one on alert at all times.
Pentagon Cancels $6B GPS Ground System Contract
April 20, 2026
The Pentagon has canceled its contract with RTX to field a ground segment to manage its most capable GPS satellites, a more than 15-year effort beleaguered by software development issues and cost overages.