Depot Maintenance (NON-IF)

The F/A-18 and EA-18G Service Life Assessment Program (SLAP) is assessing the structural and subsystem conditions of the F/A-18 and EA-18G fleet in order to determine what modifications are necessary to extend the aircraft designed life limits to allow it to achieve Chief of Naval Operations (CNO) inventory requirements. The goal of the F/A-18 and EA-18G SLAP program is to identify critical structures and components that can achieve the extended service life limit goals. SLAP consists of structural investigations of the main landing gear, arresting hook and catapult back-up structures, vertical tails, wings and fuselage. A second effort is to evaluate the subsystem components (hydraulics, wiring, actuators, etc.) to identify over and above inspections, overhaul intervals or replacement schedules to fly past design life limits. The current life limits for the F/A-18 E/F are 6,000 Flight Hours (FH), 2,250 catapults/arrestments (Cat/Traps) and 15,750 total landings; EA-18G are 7,500 FH, 2,550 CAT/Traps and 17,850 total landings. The F/A-18 SLAP program of record states the SLAP goals as 10,000 FH, 2,917 Cat/Traps and 18,750 total landings. The EA-18G SLAP program of record states the SLAP goals as 12,000 FH, 3,500 Cat/Traps and 22,500 total landings. The primary objective of F/A-18 and EA-18G SLAP is to determine if the stated SLAP goals are feasible and to determine what modifications are required, if applicable, to extend the airframe. An increase in total landings and flight hours would allow the F/A-18 and EA-18G aircraft to operate for a prolonged period of time in order to meet CNO inventory requirements. The requirements are integrated with the Joint Strike Fighter planned introduction to ensure mission readiness. This effort is required to be conducted for these airframes and subsystems to ascertain what actions and modifications must be taken to safely operate each system beyond its designed life until the targeted end of service life.

MH-60 SLAP is assessing the primary aircraft structure and subsystem condition of the MH-60 fleet in order to evaluate the airframe's ability to meet its designed service life of 10,000 hours. SLAP will determine the efforts necessary to extend the aircraft design life limits to meet Chief of Naval Operations (CNO) operational inventory requirements through FY 2050. The highest flight time MH-60S helicopters are expected to exceed the design life limit in 2027, at which time as many as 30 aircraft per year could be removed from flight status without a SLAP and follow-on Service Life Extension Program (SLEP). The highest flight time MH-60R helicopters are expected to exceed the design life in 2034. MH-60 SLAP is comprised of two distinct assessments: investigative inspections and analysis of fleet assets, which will identify current trends that either prohibit the MH-60 from reaching its design life or the required life based on operational inventory requirements; and forward-looking analysis, which will identify future risks not yet realized on fleet assets. These assessments will consider the fatigue life of airframe structure as well as the health of aircraft subsystems. The airframe structural assessment consists of investigations of the cockpit beams, main gearbox beams/frames, upper deck, engine mount, lower tub, main landing gear, tail landing gear, cargo hook, transition splice and tie-down fittings/structure, tailcone, tail gearbox, intermediate gearbox, stabilator, manufactured joints/splices, and flight controls support structure. The aircraft subsystems assessment will evaluate wiring, engines, rotor brake, hydraulic, flight controls, avionics components and infrastructure, etc., to identify over-and-above inspections, overhaul intervals or replacement schedules to fly beyond the current design limit assumption. Assessment findings will be used to determine the technical requirements for a future SLEP. FY 2027 budget requests funds to continue the SLAP analysis and engineering development that needs to occur to extend the useful life of the MH-60S and ramp the SLAP effort on the MH-60R, to include high-time fleet aircraft detailed inspections/assessments until transition to Future Vertical Lift-Maritime Strike (FVL-MS).

The T-45 Service Life Assessment Program (SLAP) is assessing the structural and subsystem conditions of the T-45 fleet in order to determine what modifications are necessary to extend the aircraft designed life limits to allow it to achieve Chief of Naval Operations (CNO) inventory requirements. The goal of the T-45 SLAP program is to identify critical structures and components that can extend the aircraft designed service life to support IPP and Naval Flight Officer Training Requirements (NTR) until 2035. This initial subsystem assessment, based on the updated fleet aircraft usage spectrum and future predicted training missions of the T-45 aircraft, found 79 dispositions requiring further analysis, teardowns, age explorations, recertification and/or testing. The assessment of the subsystems that make up these 79 dispositions will address all critical subsystems required and their ability to maintain IPP/NTR until 2035, analysis and studies will be conducted to outline improvements, assess manufacturing capabilities, prototype redesign and test of subsystems for trainer aircraft. The current life limits for the T-45 is 13,000 Flight Hours (FH). The T-45 SLAP program of record states the SLAP goals is 19,800 FH. This effort is required to be conducted for these subsystems to ascertain what actions and modifications must be taken to safely operate each system beyond its designed life until the targeted end of service life.