
USAF SAOC ‘Doomsday Plane’ Begins Flight Tests
Overview
The US Air Force doomsday plane SAOC has begun flight testing, marking a major step toward replacing the ageing E-4B Nightwatch fleet. Sierra Nevada Corp. (SNC) flew the first test sortie on August 7 from Dayton, Ohio, and will continue flight and ground trials until 2026 in Dayton and Wichita. Defence News The Aviationist
Why the SAOC matters
In a national crisis, the US Air Force doomsday plane SAOC will serve as a hardened, airborne command post. It will keep the President and national command authorities connected to U.S. forces, even if ground nodes fail due to nuclear attack or other catastrophe. afgsc.af.milWikipedia

First flight and test campaign
SNC’s Dayton Aviation Innovation and Technology Centre hosted the first flight of the US Air Force doomsday plane SAOC. Testing through 2026 will de-risk the design early, proving communications, power, and survivability baselines before deep modifications begin. Wichita will support elements of the campaign as systems mature. The Aviationist Defence News
From 747-8 to hardened command post
Engineers are converting Boeing 747-8 airframes into the US Air Force doomsday plane SAOC. They are adding EMP and radiation hardening, high-gain antennas, secure computers, and mission systems to ensure resilient command-and-control under extreme conditions. Four 747-8s are already at Dayton for conversion activity. The Aviationist
Programme scope, cost, and schedule
The Pentagon awarded SNC a $13 billion contract in 2024 to deliver five aircraft for the US Air Force doomsday plane SAOC programme, replacing four E-4Bs. Current plans target completion by July 2036, aligning production, integration, and test schedules across multiple sites. SN Corporation

Industrial footprint in Ohio and Kansas
To deliver the US Air Force doomsday plane SAOC, SNC is expanding in Dayton. The firm opened a second large hangar in late 2024 and broke ground on two more; the first of these new facilities is slated to open in October 2025. This growth underpins long-term integration and test capacity. SN Corporation Shook Construction
What it replaces: E-4B Nightwatch
The E-4B, the current National Airborne Operations Centre, has served for decades and nears the end of its service life. The US Air Force doomsday plane SAOC will assume that mission with modern NC3 connectivity, endurance, and protection. afgsc.af.mil
Outlook
As testing advances, the US Air Force doomsday plane SAOC will lock down its technical baseline. Consequently, the program aims to reduce downstream risk, control costs, and maintain schedules while delivering a survivable command node for the nuclear enterprise and broader crisis response. Ultimately, the US Air Force doomsday plane SAOC anchors continuity of government in the most demanding scenarios.
References
- Defence News—Flight tests begin on the US Air Force’s new ‘doomsday plane’. https://www.defensenews.com/air/2025/09/04/flight-tests-begin-on-us-air-forces-new-doomsday-plane/ Defense News
- SNC — Air Force Awards SNC $13B Contract for New ‘Doomsday’ Plane. https://www.sncorp.com/news-archive/in-the-news-air-force-awards-snc-13b-contract-for-new-doomsday-plane/ SN Corporation
- The Aviationist — U.S. Air Force E-4C SAOC Begins Flight Testing. https://theaviationist.com/2025/09/04/usaf-e-4c-saoc-begins-flight-testing/ The Aviationist
- U.S. Air Force (AFGSC) — E-4B Fact Sheet. https://www.afgsc.af.mil/About/Fact-Sheets/Article/1056977/e-4b/ afgsc.af.mil