E-6 Series

The E-6 Series line item in the Navy's FY 2026 Aircraft Procurement budget funds a comprehensive set of modifications to the E-6 Mercury fleet, a critical airborne command, control, and communications (C3) platform supporting national leadership and strategic forces. The objective of this program is to sustain and enhance the E-6B's operational readiness, survivability, and mission effectiveness through targeted investments in safety, technology modernization, communications, and life extension. All sixteen aircraft in the E-6 fleet are slated to receive these upgrades, unless otherwise noted.

Safety Deficiencies (OSIP 008-02) aims to correct high-risk safety hazards that threaten personnel and equipment, directly supporting mission readiness. This includes replacing Kapton wiring, upgrading the Enhanced Ground Proximity Warning System (EGPWS), improving the Auxiliary Power Unit (APU) exhaust box and tail pipe, replacing flight deck seats, and upgrading oxygen masks. The FY 2026 request notably increases to begin procurement of Kapton Abatement A kits, following a 2023 System Safety Risk Assessment that elevated the urgency of this wiring replacement due to serious risk classification.

Tech Insertion (OSIP 003-04) addresses obsolescence, supportability, and interoperability issues by integrating commercial and government off-the-shelf (COTS/GOTS) technologies. Key efforts include upgrades to GPS systems, fuel tank sealant improvements, color weather radar, and cockpit avionics. These modifications are designed to ensure continued access to controlled airspace, improve navigation reliability, and reduce aircraft weight. FY 2026 funding supports expanded training and the start of color weather radar installations.

Service Life Extension Program (SLEP) (OSIP 003-07) is focused on extending the operational life of the E-6B fleet to at least 2038. This is achieved through structural strengthening, enhanced fatigue tracking, and timely modifications to prevent aircraft grounding. FY 2026 funds support ongoing procurement and installation of structural kits and related engineering and support activities.

Communications Upgrade (OSIP 012-07) modernizes the E-6B's digital communications architecture, including High Frequency (HF) and Very Low Frequency (VLF) radio systems, to improve airborne command post operations and ensure robust over-the-horizon links with strategic forces. The program also incorporates Internet Protocol (IP) connectivity and wideband capabilities for voice, video, and data. FY 2026 funding supports procurement of installation kits and expanded training for new systems.

Multi-Role Tactical Common Data Link (MR-TCDL) (OSIP 013-10) integrates Army-developed data link hardware into the E-6B to expand communication bandwidth and ensure interoperability with U.S. Strategic Command's National Command and Control Architecture. FY 2026 funding completes installation of security updates as directed by the Senior Leader Network Program Office.

Auxiliary Power Unit (APU) (OSIP 002-12) upgrades are intended to resolve safety and reliability concerns identified during operational testing and fleet use. These modifications increase power capacity and address life-limiting deficiencies, ensuring the E-6B can meet evolving mission requirements. FY 2026 funding supports final installation activities and contractor oversight.

Family of Advanced Beyond-Line-of-Sight Terminals/Presidential and National Voice Conferencing (FAB-T/PNVC) (OSIP 014-14) replaces obsolete MILSTAR and SECN terminals with modern USAF-provided hardware, including Red Switch integration for secure conferencing. These upgrades are critical for maintaining secure, survivable communications for national leadership. FY 2026 funding supports the final phase of installations and support.

Mission Systems (OSIP 014-21) focuses on addressing mission system obsolescence and cyber vulnerabilities by modernizing hardware and software, including the Mission Computer Modernization and Mobile Support and Sustainment System. FY 2026 initiates new efforts for Mobile SASS, with procurement and installation planned for future years.

In Flight Trainer (002-22) funds the modification and airworthiness certification of a former UK E-3D aircraft to serve as an E-6B in-flight trainer, supporting crew proficiency and readiness. FY 2026 does not request new funds, as prior years covered the necessary de-militarization and modification work.

Inactive OSIPs represent prior year totals for completed or discontinued modification efforts and do not require additional funding in FY 2026.