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.
Boeing received a $2.47 billion Air Force contract Nov. 25 for 15 more KC-46s, bringing to 183 the number of Pegasus tankers on contract to all customers, foreign and domestic. The new contract—for Lot 12 of the initially planned KC-46 buy—is to be completed by 2029.

