The US Marine Corps is switching to a new way of tracking the fatigue life of its Boeing AV-8B Harrier II fleet as it struggles to keep the venerable jump jet in service until 2030, the US Naval Air Systems Command (NAVAIR) says. But the USMC is also doing what it can to keep the Harrier's avionics up-to-date as possible, the service says.
"The AV-8B is completing transition to a fatigue life expended model of structural fatigue tracking vice a total flight hour model that was used originally," NAVAIR says. "This model more effectively tracks the structural health of the aircraft by recording actual flight loads experienced instead of applying a worst case per flight hour service life penalty."
©US Marine Corps
Once the transition to the new tracking methodology is completed, the USMC expects the AV-8B to remain structurally healthy without major modification until after 2030. "Structural modifications are a fact of life for any aging platform, however, as the predictive models must continuously evolve to keep pace with actual aircraft employment, emergent structural modifications/repairs will most certainly persist through end of service, independent of the actual date," NAVAIR says.
While the Harrier is structurally sound, securing a supply of spare parts has proven to be challenging for NAVAIR. "The focus is on development of an effective strategy that provides improved near/mid-term availability of high and low demand repairable and consumable material requirements to maintain readiness goals while providing long-term sustainment," NAVAIR says.
The problem was partially solved by purchasing 72 surplus BAE Systems GR9 Harriers, spare parts and associated support equipment from the UK. The UK aircraft and their associated hardware were transferred to the US over a period of five months, NAVAIR says. The addition of the British hardware to the supply chain will help the USMC sustain the Harrier to 2030. Previously, the lack of spares posed a real threat to the service's continued operation of the type.
"The sale of these [aircraft] supplies critically needed AV-8B aircraft parts," NAVAIR says. "Many of these parts are obsolete with no source of manufacture. As a result, the USMC has realized an immediate improvement in readiness."
Moreover, NAVAIR says: "Future capability is enhanced by the ability to maintain aircraft operability that would be otherwise be threatened by a dearth of necessary parts."
But contrary to media reports, the USMC never had any intention of flying the British jets. Nor did the service ever consider replacing the Boeing F/A-18D fleet with the GR9. "The USMC operation of UK Harriers was not under consideration," NAVAIR says.
Other NAVAIR Harrier sustainment efforts include entering into new contracts to improve the overhaul of repairable spare parts and long-term agreements for the supply of consumables.
"It is important to note, with the introduction of the additional material from the UK GR9 acquisition, the programme office is acutely sensitive to the fragility of the supplier/industrial base as the UK leaves the Harrier community and reduces the worldwide Harrier market to three remaining nations (US, Spain, and Italy)," NAVAIR says. "As a result, the programme office is taking a 'disciplined' approach to the infusion of the material into the US supply system."
Meanwhile, the USMC is doing what it can to keep the AV-8B's avionics relevant to 2030.
"Continuing modernization of the AV-8B is a must to reach the out of service date, both from a mission systems combat relevancy perspective and a survivability perspective," says Major William Maples, Harrier requirements officer at USMC headquarters. "The aircraft is funded for improvements to the Operational Flight Program (OFP), Required Navigation Performance/Area Navigation (RNP/RNAV) capability, and digital cockpit recorder over the next four years."
The effort is designed to ensure that the Harrier is digitally interoperable with the Marine Air Ground Task Force (MAGTF), Maples says. The Harrier is a vital part of a Marine Expeditionary Unit (MEU) as its only fixed-wing combat aircraft. "The Harrier community will continue to bear a proportional load of Marine Expeditionary Unit and overseas contingency operations deployments through the end of its service life," he says.
The USMC has not ruled out future upgrades to the jet, and the AV-8B Joint Systems Support Activity at China Lake, California, continues to look for improvements that could be added to the aircraft. But "additional funding will need to be identified in future budgetary cycles to continue improvements to the avionics and survivability suites currently employed in the Harrier," Maples says.
Source: Flight International