The U.S. Air Force announced on Aug. 4 that it had ordered two commercial 747-8 aircraft for future modifications into Air Force One.
By Boeing_747-8F_render_in_flight.jpg: *Boeing_747-8_N747EX_First_Flight_2-8-2010.jpg: moonmPilved.lennukiaknast.jpg: Ave Maria Mõistlikderivative work: Altair78 (talk)derivative work: Altair78 (Boeing_747-8F_render_in_flight.jpg) [CC BY-SA 3.0], via Wikimedia Commons
The press release says the program expects to begin aircraft modifications in 2019 and reach initial operational capability in 2024.
The service added that the negotiated price paid is not releasable as the aircraft were purchased through commercial contracting procedures.