Boeing has begun modifications to the first of two commercial 747-8 airliners which are to be turned into US Air Force (USAF) VC-25B aircraft.

Known by its “Air Force One” call sign when the US president flies aboard, two VC-25B are to operate as the USA’s top executive transports for the next 30 years. Modifications are being done at Boeing’s San Antonio, Texas facility, says the USAF.

Boeing VC-25B rendering

Source: Boeing

Boeing VC-25B rendering

“The first phase of aircraft modification involves cutting out large skin and structure areas in both the forward and aft lower lobes of the aircraft and then installing two newly manufactured superpanels,” says the service. “The superpanels contain structural upgrades and cutouts for the VC-25B lower lobe doors, including internal airstairs for mission requirements.”

The USAF is working to replace its current fleet of presidential aircraft, two 747-200-based VC-25A aircraft delivered in 1991, with two 747-8s originally built for Russian carrier Transaero, which filed for bankruptcy in 2015 before it could take delivery. The commercial airliners need extensive retrofits to be transformed into the VC-25B configuration.

For example, the two airstair doors, one forward of the wing and one behind the wing, did not come as part of the commercial airliner configuration, according to USAF acquisition documents released in July 2018. The retractable airstairs are to allow the aircraft to emplane passengers and crew without needing to rely on ground-based staircases.

The commercial 747-8s have been stripped of many of its typical components as well, says the USAF.

“Boeing prepared the two aircraft for modification start by removing the commercial interiors, engines, auxiliary power units, and numerous secondary system components,” says the service. “Additionally, Boeing placed a sophisticated jacking and crib mechanism under each aircraft to reduce structural stress for the initial modification phases.”

The V-25B is to be retrofitted so that the president of the USA can run the federal government, including commanding and controlling the US military, while in flight. As such, detailed information about the aircraft’s components and capabilities are classified or tightly controlled.

“The VC-25B modifications to the 747-8 aircraft will include electrical power upgrades, a mission communication system, a medical facility, executive interior, and autonomous ground operations capabilities,” says the USAF.

Additional modifications will include integration of a military GPS into the VC-25B’s flight management system and identification friend-or-foe capabilities, according to the previously released acquisition document.

The aircraft also is likely to include missile warning systems and defensive technologies, such as chaff dispensing systems and directional infrared countermeasures.

Boeing was also asked to replace the existing auxiliary power unit (APU), usually a Pratt & Whitney PW901A/C on the commercial airliner, with two APUs from unnamed sources. According to the book Air Force One by Robert Dorr, a second APU was installed on previous presidential aircraft to ensure they were “self-sufficient on the ground”.

The two VC-25B aircraft are scheduled to be delivered by December 2024.