E-4B Aircraft Modernization

Abstract

The four (4) aircraft E-4B National Airborne Operations Center (NAOC) fleet satisfies the military need for an airborne operations center with communications capabilities permitting military and civilian leadership to monitor and control military and civil national assets during all phases of conflict (nuclear and non-nuclear) or natural disaster. The E-4B NAOC fleet also satisfies the military requirement to provide a highly survivable node of the National Military Command System (NMCS). This program's developmental modifications include, but are not limited to, upgrades and enhancements to aircraft structures, propulsion system, fuel system, environmental control system, electrical generation and distribution systems, flight safety and navigation systems (with their associated communications equipment), and the Systems Integration Lab. Modifications may enhance the aircraft's mission capabilities necessary for the E-4B fleet to execute its mission, to include but not limited to those necessary for the Senior Leadership Command, Control and Communications System (SLC3S), National Leadership Command Capability (NLCC), and Nuclear Command, Control, and Communications (NC3). Funds may also be used to explore and develop modifications, upgrades, and future systems required to meet evolving mission requirements. This budget supports the following developmental modifications and studies/projects currently underway or planned for accomplishment: - Survivable Super High Frequency (SSHF) will upgrade and replace portions of the E-4B's Jam-Resistant Secure Communications (JRSC) system to meet existing Presidential Policy Directive (PPD)-35 and National Security Presidential Directive (NSPD)-51/Homeland Security Presidential Directive (HSPD)-20 requirements and to ensure continued connectivity and interoperability as satellite and communications infrastructure evolves. Expected modifications include, but are not limited to, component and sub-system upgrades and replaces portions of the current Super High Frequency (SHF) system that are obsolete or near end of service life. A replacement to the SHF system is required as secure, survivable communications capability transitions from the Defense Satellite Communications System (DSCS). A risk-reduction study was completed in FY19 to further define the acquisition strategy of the SSHF program. The program will be acquired in 2 increments and each increment will be split into 2 installs to expedite fielding and reduce impact to Aircraft Availability. Increment 1A will upgrade the existing Ka-band system. Increment 1B will include technical solutions such as upgrading the existing modems and systems integration lab. Increment 2A will include new modem technology and common workstation. Increment 2B will include a new Ku-band system upgrades to the X-band system. - The E-4B Systems Integration Laboratory (SIL) program will develop a test environment configured to represent the mission systems of the E-4B with connectivity to mission networks and services. E-4B SIL started as the Test Accreditation Integration Lab (TAIL) 5 for development of the E-4B SSHF program. The E-4B SIL program will expand the capabilities of TAIL 5 beyond SSHF to include the other mission communication systems within the E-4B. The E-4B SIL is necessary to minimize modernization and technical refresh schedules by reducing time on aircraft for install, test, ground connections/configurations, technical orders, redlines/rework, and training. Schedule reduction by the E-4B SIL will directly support increased Aircraft Availability (AA). The E-4B SIL will be developed in three blocks in FY24-FY27: Block 1 will focus on voice systems, Block 2 will focus on data systems, and Block 3 will integrate the remaining communication systems. The total cost of the E-4B Survivable Super High Frequency Increment 2 Rapid Prototyping Middle Tier of Acquisition effort is 174.7 million, including RDT&E and procurement of prototype units. The E-4B SSHF Inc 2 RP program is not fully funded across the Future Years Defense Program. The Department of the Air Force is assessing all options to address the funding shortfalls for MTA programs including additional funding in a future budget request, performance trades based on technical maturity, or transition to alternative pathways. This program element may include necessary civilian pay expenses required to manage, execute, and deliver weapon system capability. The use of such programs funds would be in addition to the civilian pay expenses budgeted in program element 0605827F, 0605828F, 0605829F, 0605831F, 0605832F, 0605833F, 0605898F, 0606398F. In FY23 0.0M was expended for civilian pay expenses in this program element, and in FY24 0.0M is forecasted for civilian pay expenses in this program element. This program is in Budget Activity 7, Operational System Development because this budget activity includes development efforts to upgrade systems that have been fielded or have received approval for full rate production and anticipate production funding in the current or subsequent fiscal year.

Document Details

• Document Type: Project
• Publication Date: Oct 01, 2025
• Source ID: 674777_0302015F_7_3600_PB_2025

Tags

Readers

• Civilian Systems Systems Program Capability Development and Upgrade Support Activity Expense and Pay Management.
• Tactical Satellite Communications Systems Engineering.

Technology Areas

• Space