T-45 Series

T-45 Series is the Navy's aircraft-modification budget line for the T-45 Training System (T45TS), covering both aircraft and Ground-Based Training Systems (GBTS). It falls under Aircraft Procurement, Navy, Budget Activity 05 and Budget Sub Activity 1, both designated Modification of Aircraft. The 193-aircraft fleet consists of tandem-seat, carrier-capable T-45 Goshawks derived from the British Aerospace Hawk and powered by a single Rolls-Royce Adour engine. The FY 2027 request continues changes to correct deficiencies found after delivery, sustain pilot training, and address critical avionics obsolescence and Diminishing Manufacturing Sources and Material Shortages (DMSMS).

T-45TS Corrections of Deficiencies (OSIP 008-95) addresses safety, reliability, maintainability, and mission shortfalls identified during testing or operational use. Its Engineering Change Proposals (ECPs) cover structural areas such as the wing centerline joint and canopy Frame 8 longeron; airframe systems including landing gear and control surfaces; and engine, starter, electrical, and related support equipment. FY 2027 supports 16 installations of the ECP-5069BAE fatigue-life-deficiency modification and continued airframe structural work. A second installation site and organic capacity at Fleet Readiness Center Southeast (FRCSE) are intended to increase throughput, while contractor labor-rate increases and a 36-month kit lead time have delayed installations.

Engine Surge (OSIP 003-03) targets a critical safety-of-flight problem in a single-engine trainer: more than 900 surge events have been documented, including more than 70 requiring engine shutdown and restart. The effort combines dry- and wet-inlet modifications with work on the F405-RR-401 engine and fuel-control system; inlet installations are underway as engine and fuel-system engineering and kit procurement continue. FY 2027 supports further inlet and ignition-coil installations, replacement of installation equipment worn by two inlet configurations, and engineering and logistics assistance for aircraft-condition issues. Limited overseas sources impose long kit lead times, while contractor costs and the FRCSE capacity expansion affect installation costs.

Avionics Obsolescence (OSIP 017-04) keeps cockpit, navigation, communications, and training equipment supportable as components age or suppliers disappear. Work includes the Mission Data Processor, Pilot Display Unit and Head-Up Display (HUD), ARC-182 radio, Tactical Air Navigation (TACAN), radar altimeter, and software and subsystem ECPs. Digital Data Set Data Acquisition Unit circuit-card upgrades preserve terrain-warning and crash-survivable recording capabilities for continued operations through 2035. FY 2027 also advances YDC and radar-altimeter modifications and associated CWSEU simulator updates; support covers major TACAN/radio, HUD, and Mission Computer Alternative installations.

Service Life Extension Program (SLEP, OSIP 022-14) responds to risks identified by the Service Life Assessment Program, which reduced the assessed service life from the original 14,400 flight hours to 13,000. Redesigned critical-load-path components are intended to extend safe life to 19,800 hours at 137 percent Fatigue Life Expended, allowing Chief of Naval Air Training requirements to be met through 2035. FY 2027 procures fuselage-repair kits and supports structural engineering, 18 different modifications, and 16 modification lines. Original-equipment-manufacturer and onsite engineering support must resolve varying aircraft configurations and condition findings during retrofit so installations do not stop; limited overseas kit sources add a 36-month lead time.

Required Avionics Sustainment Program (RASP, OSIP 006-16) protects T-45 access to the Federal Aviation Administration's (FAA) modernized National Airspace System and avoids disruption to strike-pilot and naval flight-officer training. Phase I provides Automatic Dependent Surveillance Broadcast Out (ADS-B Out) through transponder, antenna, air-data-computer, pilot-interface, Mission Display Processor software, and simulator changes. Phase II addresses display and Global Positioning System Inertial Navigation Assembly obsolescence and develops Midair Collision Avoidance Capability, with ADS-B In an assumed enabler. FY 2027 supports Caution Warning System Electronics Unit (CWSEU) aircraft and simulator changes and work on collision avoidance and Synthetic Strike Fighter Mission Systems; ADS-B installation was delayed by test-kit and production-kit lead times.

Physiological Episode Mitigation (OSIP 012-19) addresses potential causes of aircrew physiological episodes across oxygen generation, environmental control, engine bleed-air delivery, piping, and failure alerts. Although episodes are trending downward, FY 2027 continues Automatic Backup Oxygen System and GGU-25 oxygen-concentrator installations and procures flex-duct/pipe kits for an oxygen-system bleed-air connection change. It also supports integrating GGU-25 monitoring data into the Crash Survivable Memory Unit/Digital Data Set to aid episode determination. Prototype-installation challenges require more than 30 significant documentation updates, and vendor engineering setbacks have delayed concentrator installations.

Inactive OSIPs records prior-year activity, including an FY 2020 enacted rescission, but has no FY 2027 request. It is separate from the six active modification efforts that make up the requested-year T-45 Series work.