An E-4B aircraft sits on the tarmac at Travis Air Force Base, Calif., Sep. 11, 2017. The E-4B participated in a flyover at the California Capital Airshow. (U.S. Air Force photo by Louis Briscese)

WASHINGTON — The Air Force has awarded Sierra Nevada Corporation (SNC) a $13 billion contract to deliver a replacement for the service’s E-4B “Doomsday” plane, the service announced tonight.

The contract for the new Survivable Airborne Operations Center (SAOC) is expected to run through July 2036, according to the announcement. The program will replace the Air Force’s aging fleet of four E-4B planes, known as Nightwatch or the National Airborne Operations Center, which typically transport the Defense Secretary but can also act as a mobile nuclear command and control outpost. 

SNC did not immediately respond to a request for comment. 

The win represents one of the largest undertakings in the mid-size firm’s history. SNC will be expected to not only incorporate military systems like air refueling and secure communications, but also harden the commercial aircraft against electronic and nuclear attack. The service is planning to acquire between eight to 10 aircraft for the SAOC program, according to Aviation Week, but will have to acquire used models if a Boeing 747  a likely candidate for the militarization effort is chosen.

According to an Air Force spokesperson, “to satisfy operational requirements, the weapon system will be comprised of a Commercial Derivative Aircraft that will be hardened and modified to meet military requirements.” The spokesperson added that the aircraft will be developed using a modular open systems approach, and that accompanying ground support systems will be set up “to enable the operations, sustainment, and future modifications of the SAOC weapon system across its lifecycle.”

“The development of this critical national security weapon system ensures the Department’s Nuclear Command, Control, and Communications capability is operationally relevant and secure for decades to come,” the spokesperson said.

The victory by SNC was largely expected after the surprise elimination of Boeing, the incumbent for the current E-4B fleet, manufacturer of the 747 and heavyweight contender for the contract, given the company’s work on similar large-scale programs like the Air Force One replacement effort. Reuters previously reported Boeing and the Air Force could not reach an agreement on the SAOC contract’s structure or data rights.  

Under appropriations passed by Congress for fiscal 2024, the Air Force has $744 million to invest in the SAOC program this year. In its FY25 request, the service is seeking roughly $1.7 billion. The SAOC program is one of several multibillion-dollar endeavors the Air Force is undertaking to modernize its nuclear portfolio, ranging from a new nuclear ballistic missile to a long-range stealth bomber.