Infrared Search and Track (IRST)

The Infrared Search and Track (IRST) program, as outlined in Budget Line Item (LI) 0515, is a Navy initiative focused on the modernization and capability enhancement of the F/A-18E/F aircraft fleet. Established in FY2021 for increased transparency, this line item funds modifications that integrate the IRST system into the F/A-18E/F, providing a critical passive sensor capability. The primary objective is to equip these aircraft with a long-wave infrared sensor, enabling detection, tracking, and engagement of airborne targets at extended ranges. This is particularly important in environments where electronic attack or radar denial is prevalent.

The IRST system, specifically the AN/ASG-34A(V)1, serves as an alternate fire control system that operates passively and out-of-band. This is essential for maintaining operational effectiveness against advanced threats in contested airspaces. The program's goals include enhancing the lethality and survivability of the F/A-18E/F by allowing it to detect and target adversary aircraft without emitting signals in the radio frequency spectrum, thereby reducing the risk of detection. This capability supports the Navy's objectives under the National Defense Strategy, enabling organic passive air-to-air kill chains and supporting the guidance of advanced missiles.

Within LI 0515, the IRST Block II Capability Improvements line item is the central focus for FY2026. The Block II upgrade represents an evolutionary step from Block I, incorporating both retrofit and forward-fit modifications, as well as integrated logistics support activities. These include special tooling, support equipment, production test equipment, and the establishment of intermediate and depot-level maintenance capabilities.

The Block II Engineering Change Proposal (ECP) achieved Milestone C in December 2018, and its development has followed an incremental approach to mitigate concurrency risks while accelerating fielding based on proven technology and design stability. Procurement objectives for FY2026 include the acquisition of IRST Block II B-Kits, which are essential for full-rate production and fleet integration. Additional procurement funds are allocated for critical software modernization, which addresses system security, correction of deficiencies, and ensures the IRST's fire control solution remains effective against evolving adversary countermeasures.

Support funding encompasses data management, training equipment, support equipment for maintenance stand-up, integrated logistics support, and other support activities necessary for operational readiness. A significant aspect of the program is the investment in organic maintenance capability, both at the intermediate and depot levels. This reduces reliance on the Original Equipment Manufacturer (OEM) for repairs, thereby lowering costs, improving repair turnaround times, and ensuring the ability to maintain and repair IRST components aboard aircraft carriers. Failure to fund these support activities would result in increased spares requirements and diminished operational readiness, particularly during periods of high operational tempo or conflict.

The IRST program also aligns with broader government efficiency initiatives, as evidenced by reductions in advisory and assistance services and civilian personnel funding for FY2026, in compliance with Executive Orders 14222 and 14210. These adjustments are intended to promote cost efficiency and workforce optimization within the Department of Defense. The program's refined contracting strategy and updated acquisition baseline further support these goals, ensuring that the Navy can field advanced IRST capabilities in a timely and cost-effective manner.