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AV-8B Harrier - Service Life

The project that eventually led to the AV-8B' started in the early 1970s as a cooperative effort between the United States and United Kingdom (UK), aimed at addressing the operational inadequacies of the first-generation Harrier. During the late 1970's, as the Marines made their plans for converting their light attack force to all V/STOL by phasing in AV-8B*s, a gap in Harrier service was discovered. The original AV-SA^s then in service with the Marine Corps were physically not going to last until they could all be replaced by Advanced Harriers. Unless some corrective action was taken, there would be a period during which the Marine Air Wings would not have any Harriers in service.

Following the withdrawal of the UK, McDonnell Douglas extensively redesigned the earlier AV-8A Harrier to create the AV-8B. Because the YAV-8B improvements were so successful, plans were made to extend the lives of the original AV-8As through a Conversion In Lieu Of Procurement (CILOP) program. In this program, modifications similar to those of the YAV-8B were made on the AV-SA.

The AV-8B made its maiden flight in November 1981 and entered service with the USMC in January 1985. Approximately 340 aircraft were produced in a 22-year production program that ended in 2003.

The US Marine Corps AV-8B fleet was introduced into USMC service in 1985 with night attack upgrades being implemented in 1988. The AN/APG-66 equipped AV-8B+ variant was introduced in 1996. Production continued until 2001. The AV-8B Harrier II fleet is set to remain in service until the time frame F-35B squadrons are expected to come to full strength, at which time the new F-35B would assume the Harrier II ground attack role. The AV-8B II fleet would probably out-last the F/A-18C/D Hornet air frames that had suffered maintenance issues. Most F/A-18C/D also accumulated flight hours more rapidly then expected, shortening time in service.

By 2010 the US Navy provided for maintaining the readiness of the AV-8B weapons system until its projected end of service, which was expected to extend to 2025 or until replaced by STOVL JSF. This requires the airframe and integrated systems to exceed planned service life and will require both structural and obsolescence solutions. Funds will be utilized to manage and prepare, process and incorporate ECPs and implement changes to sustain and improve AV-8B weapons system readiness including safety, mission availability, structural integrity, and component (avionics/systems) reliability, maintainability, and obsolescence conditions as they arise. Due to fleet aircraft PAA inventory shortfalls, all depot level modification installations must be planned and programmed concurrent with Integrated Maintenance Plan (IMP) scheduled depot overhaul events to minimize aircraft out-of-service periods, to the extent allowed by authorized budget.

Power Plant changes are required throughout the aircraft service life as the aircraft ages and operationally revealed deficiencies are discovered, researched and solutions engineered. The Component Improvement Program (CIP), which is RDT&E funded, provides for the developing and demonstrating of the engineered solutions to these deficiencies and through the Engineering Change Proposal (ECP) process the Power Plant changes are initiated. The power plant program procures the necessary kits, installation, non-recurring engineering, and technical data. The kits provided are for engine and propulsion related hardware to support the AV-8B F402 engine such as nozzle guide vanes (NGV), Pilot Lever Angle Units (PLAU), Fuel Control Units, Generator Turbine Starters (GTS) and accessory components, rotors and vanes for compressor sections, power turbines, combustion sections, exhaust ducts, engine monitor systems, and blade and vane coatings and foils to improve Foreign Object Damage (FOD) tolerance.

AV-8B Harrier II air frames are set to last longer due to improved maintenance conditions. The USMC received an abundance of spare parts when the UK Royal Navy and Air Force retired 71 Harrier air frames. Due to component obsolescence concerns and supply shortfalls, the Department purchased 72 GR-9 aircraft, 38 MK-1 07 engines, parts supply, and support equipment from the United Kingdom in 2011. The GR-9 buy was meant to fill a supply gap allowing the Naval Supply Systems Command immediate access to supply inventory, to develop long term sustainment strategies and give industry time to re-develop pmts production lines to support the AV-8B until transition to the F-35 is complete.

Retired eight years earlier than planned. the UK had previously spent around £1 billion to upgrade the Harrier fleet in a project begun in 2005. These air frames provide maintenance crews with common structural components to ensure USMC fleet readiness. Until at leaswt 2026 USMC Harriers would continue with their current missions profiles of close air support and air interdiction in support of the newer F-35B.

The AV-8B was originally designed as a 6,000-hour airframe with expected service life through 2012. In 2010, the Department transitioned to a Fatigue Life Expended (FLE) model that more accurately measures actual stress history on individual airframe components, enabling the airframe to 11y beyond 6,000 hours. By 2017 fleet average for all three single-seat variants of the AV-8B Harrier was 34.6 percent FLE; there was sufficient airframe life left in these aircraft to reach their eventual end of service.

By 2012 the US Marine Corps switched to a new method of tracking the fatigue life of its AV-8B Harrier II fleet as part of the effort to keep the jump jets in service until 2030. US Naval Air Systems Command (NAVAIR) said the USMC is also doing what it can to keep the Harrier's avionics up-to-date as possible. "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 said. "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."

Once the transition to the new tracking methodology was completed, the USMC expected the AV-8B to remain structurally sound 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 said. While the Harrier is structurally sound, securing spare parts had proven challenging for NAVAIR. As an out-of-production aircraft, the AV-8B program continued its focus on sustainment efforts to mitigate significant inventory shortfalls, maintain airframe integrity, achieve full Fatigue Life Expended, and address reliability and obsolescence issues of avionics and subsystems.

To address degraders to readiness, the AV-8B conducted the Harrier Independent Readiness Review (HIRR) in December 2014. The focus of this study was to address out of reporting aircraft, manpower deficiencies, and material degraders. Since the conclusion of the HIRR there had been a positively trending readiness recovery in the AV-8B f1eet due in large part to executive-level engagement with OEMs, vendors, and all DoD commands that have a supporting relationship with the AV-8B program.

By 2017 the Marine Corps inventory consisted of 126 AV-8B aircraft. This included 34 Night Attack, 76 Radar aircraft and 16 TAV-8B trainers. These aircraft supported 5 operational squadrons of 16 aircraft each (Primary Mission Aircraft Authorization of80). To date, the AV-8B !1eet was averaging 11 aircraft out-of-reporting for Planned Maintenance Interval and special re-work, with a five-year average of 18.1 percent per year. Most importantly, the Harrier had historically suffered from inadequate supply support, drawing down the number of aircraft that can train, deploy, and support the Marines.

By 2017, over 75,000 parts exceeding $71 million had been used from the GR-9 purchase. This decision had an immediate impact in reducing supply backorders. However, a reduction in demand signal from the GR-9 and other lifetimetype buys may cause additional reduction in sub vendors and supply contractors unless carefully managed. The AV-8B continued to be in high demand deploying in support of Combatant Commander (CCMD) requirements and operational contingencies.

Sub-contractors and vendors divested manufacturing lines of AV-8B material in anticipation of thc 2012 sundown and the United Kingdom Royal Air Force divestiture of the AV-8B (GR-9) airframe. Delays in F-35 procurement, coupled with F/A-18A-D out-of-reporting challenges led to changes in the Marine Corps' TACAIR transition order planning to shut down three F/A-18 squadrons early and extending the service of the AV-8B to mitigate a growing Marine Corps TACAIR inventory shortfall.

The Marine Corps’ fleet of AV-8B Harrier II attack aircraft may serve until 2028, a two-year extension of the previous plan, the Corps’ aviation chief told Congress 04 April 2019. “We will continue to be a fourth-gen/fifth-gen [tactical aircraft] fleet out until about 2030, with Harriers probably going to 2028 and F/A-18s going to 2030-2031,” said Lt. Gen. Steven R. Rudder, the Marine Corps’ deputy commandant for aviation. He testified during a hearing of the Tactical Air and Ground Forces subcommittee of the House Armed Services Committee. During FY 2019, the AV-8B Harrier program completed critical Fleet required Validation/Verifications to enhance flight safety, increase readiness and improve supply chain asset management.

BAE Systems and Vertex Aerospace signed a nine-year agreement 12 January 2021 to enhance availability of the U.S. Marine Corps’ AV-8B Harrier II fleet. The U.S. Department of the Navy awarded Vertex Aerospace LLC the $123 million Contracted Maintenance, Modification, Aircrew, and Related Services (CMMARS) task order in July 2020 to provide aircraft maintenance and Contractor Logistics Support (CLS) services for the U.S. Marine Corps’ AV-8B Harrier fleet. Vertex Aerospace selected BAE Systems as a subcontractor for the new logistics support contract, which will ensure increased efficiency of maintenance operations for the Harrier fleet using predictive maintenance techniques and smart stock optimization tools. Together, BAE Systems and Vertex Aerospace will support the crucial training and combat operations conducted from U.S. Navy’s aircraft carriers, amphibious assault ships, and forward operating bases.

This contract built on BAE Systems’ existing role in maintaining the AV-8B Harrier’s reaction control system and providing engineering and technical support. Engineers from BAE Systems will work alongside Vertex and the U.S. Marine Corps at stations in: Cherry Point, North Carolina; Yuma, Arizona; and, Madison, Mississippi. They will be supported by a specialist team in the UK with a proven pedigree of delivering maintenance and support contracts for the UK Royal Air Force.

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Page last modified: 01-07-2021 17:55:20 ZULU