E-4

The E-4 Air Force program is dedicated to enhancing the capabilities of the E-4B fleet, which functions as the National Airborne Operations Center (NAOC). This initiative focuses on maintaining the airworthiness of these aircraft, which are modified Boeing 747-200 models, ensuring they meet Federal Aviation Agency (FAA) standards. The modifications aim to improve flight control, navigation, communication systems, and primary mission equipment to effectively support the NAOC mission. As these aircraft near their design service life limits by the early 2030s, addressing maintenance issues due to aging is essential for maintaining operational availability.

A primary objective is to tackle Diminishing Manufacturing Sources and Material Shortages (DMSMS) affecting both primary mission equipment and airframe components. This challenge is intensified by the decreasing number of Boeing 747-200 aircraft in commercial service. The program also supports emerging modification requirements, government travel, advisory services contracts, and research and development efforts. Key initiatives include upgrading communication systems to comply with Presidential Policy Directives and ensuring interoperability with evolving satellite networks.

The Advanced Extremely High Frequency/Presidential National Voice Conferencing (AEHF/PNVC) system is a significant focus for FY25. It involves installing a Family of Advanced Beyond Line-Of-Sight Terminals (FAB-T) to replace outdated systems like MILSTAR/SECN. This upgrade ensures compliance with directives such as PPD-35 and NSPD-51/HSPD-20 while maintaining secure communications through protected wideband satellite networks. Additionally, the Low Frequency Transmit System (LFTS) program aims to replace unsustainable VLF/LF transmit systems with new technology to maintain constant connectivity between national leadership and military forces.

The Survivable Super High Frequency (SSHF) modification seeks to enhance jam-resistant secure communications by upgrading obsolete components of the current SHF system. This effort aligns with transitioning secure communications capabilities from older satellite systems like DSCS. The SSHF program will be implemented in two increments: Increment 1 focuses on technical solutions such as modem upgrades and system integration labs, followed by Increment 2 which includes new modem technology and Ku-band system enhancements. These efforts are crucial for ensuring continued connectivity as communication infrastructures evolve.