Other Aircraft

The LI OTHACF - Other Aircraft line item in the Air Force's FY 2026 budget request is focused on the advance procurement and modification of in-service aircraft. It specifically supports the LGM-35A Sentinel Secondary Launch Platform - Airborne (SLP-A) program. This line item is part of the Aircraft Procurement, Air Force appropriation, under Budget Activity 05 for the modification of in-service aircraft. The primary objective is to ensure continued strategic nuclear deterrence by modernizing and maintaining airborne launch capabilities for the Minuteman III and future Sentinel weapon systems.

The LGM-35A Sentinel Secondary Launch Platform - Airborne (SLP-A) program aims to deliver an air-based, secondary launch system that is configurable for both the legacy Minuteman III and the new Sentinel ICBM systems. SLP-A is designed to replace the aging Airborne Launch Control System and mitigate operational risks associated with outdated hardware. The program's goals include reassessing and refining requirements, maturing system design, and mitigating cost and schedule risks, as directed by the Secretary of Defense's Nunn-McCurdy recertification and the Milestone Decision Authority's rescission of the 2020 Milestone B decision.

The SLP-A capability is being developed in incremental phases to meet operational requirements set by USSTRATCOM. The initial baseline capability will provide two-way voice, one-way data, and line-of-sight (LOS) launch for Minuteman III systems. A subsequent upgrade will enable full Sentinel capability, adding two-way voice, two-way data, Emergency Action Message relay, and beyond-line-of-sight (BLOS) launch capability for the Sentinel weapon system. This incremental approach ensures flexibility and continuity of strategic command and control as the Air Force transitions from Minuteman III to Sentinel.

The SLP-A system is built on a modular open-system architecture, which maintains commonality with the Sentinel ground system and leverages the Sentinel Common Crypto design for NSA cryptographic certification. This architecture facilitates integration aboard Navy E-6B aircraft and allows for future re-hosting to other platforms. The open-system approach is intended to streamline upgrades, reduce integration complexity, and ensure long-term adaptability to evolving mission requirements.

For FY 2026, the budget justification requests advance procurement funding for SLP-A E-6B aircraft group-B kits. These kits consist of classified, long-lead, line replaceable unit (LRU) components, including radios, transceivers, modems, high power amplifiers, computer components, and electronic circuit cards. Procuring these components in advance is necessary to support the timely incremental installation of SLP-A kits and to avoid delays in meeting operational milestones.

The program elements associated with this line item include several elements supporting broader Sentinel and airborne launch control system development. The Air Force Program Office is working closely with stakeholders to update requirements, quantities, and milestones based on ongoing reassessments, ensuring alignment with strategic objectives and risk mitigation strategies.