2008/08/19

av-8

AV-8 Harrier

AV-8 Harrier Variants



The AV-8B is scheduled to remain in service until the introduction of replacement aircraft in 2015. Three variants of the aircraft are in service: the Day Attack, Night Attack, and Radar/Night Attack Harrier. The Marine Corps is remanufacturing 72 day-attack aircraft into radar/night attack aircraft. The final projected inventory includes 36 day-attack, 56 night-attack, and 99 radar/night-attack aircraft.

Both Hawker-Siddley in the United Kingdom and McDonnell Douglas Aircraft in the United States who had become the American associate contractor, could see ways to improve the Harrier. In 1973, a joint advanced Harrier program was undertaken but the costs of both airplane and Rolls-Royce engine development led to abandonment of the proposed AV-16A advanced Harrier.


AV-8A Harrier I


Before it entered RAF service, the US Marine Corps evinced a major interest in the Harrier for attack missions, and procurement of Marine AV-8As was initiated. The Harrier entered service with the RAF and the U.S. Marines in the early seventies. It was followed in both services by a limited number of two-place trainer versions, designated TAV-8As for the Marines.

In 1982, after eleven years of AV-8A operational flying, including 55 peacetime aircraft losses, the Commandant of the time (Gen Robert Barrow) asked the Harrier community to address the serious problem of flight safety. The impetus for his concern was "a high mishap rate within the AV-8A community… anticipated continuing turbulence… and a pressing requirement to reduce the mishap rate in order to provide the assets needed for successful transition to the AV-8B." At the time, the community had a cumulative Class A rate of 39 per 100,000 flight hours. This caused decision-makers to question whether sufficient aircraft would be available to close the gap with the AV-8B, which was scheduled to begin introduction 2½ years later. The resulting "AV-8A Training/Safety Conference" reviewed mishap cause factors in an attempt to find trends and deficiencies which could be addressed to reduce pilot and airplane losses.

Injection of money to solve AV-8A unique hardware deficiencies was problematic given the funding emphasis for the new AV-8B at that time, so the conference focused on operational, training and other low cost solutions. Their recommendations included terminating night shipboard operations, flight demonstrations, and detachment deployments. (Only full squadrons should deploy, they said.) They also made major improvements to the Fleet Replacement Squadron (FRS) syllabus and to the pilot selection/retention policies. They recommended supplementing maintenance departments with contractor support, increasing squadron manning, and front loading the supply system -- all in an effort to improve aircraft availability and provide pilots with more flying time (15 sorties per month per pilot was the goal). Most recommendations were carried out, one major exception being the recommendation to stop detachment deployments. From implementation of the 1983 initiatives through the last flight of the AV-8A in 1987, the community improved its cumulative Class A rate to 19.5 per 100,000 flthrs – a 50% reduction.


AV-8B Harrier II


The T/AV-8B Harrier II Weapon System, from here on referred to as the AV-8B, with its superior capability for light attack and air-to-air missions, replaced the AV-8A/C and A-4M aircraft.

The AV-8B is a high performance, single-engine, single-seat, Vertical/Short Take-off and Landing (V/STOL) attack aircraft. It was introduced to the Fleet Marine Forces (FMF) in January 1985 after a successful prototype demonstration and Full Scale Development Program. Consistent with the long-standing Marine Corps vision of attaining an all V/STOL amphibious force, the AV-8B replaced both the A-4M and AV-8A/C -- the light attack portion of the Marine Tactical Aircraft (TACAIR) force.

Building on the technical accomplishments of the joint program, McDonnell evolved a revised design configuration, incorporating a composite structure wing, which promised most of the AV-16's capabilities without a new Pegasus development. McDonnell Douglas arrived at the current AV-8B wing-nozzle-flap configuration, which resulted in an increase of more than 6,000 lb of lift beyond that produced by the AV-8A arrangement. The AV-8B wing design has a thicker wing with better performance at high speeds, better fuel consumption, and provides an increase in internal fuel capacity of over 40 percent. Following full-scale wind-tunnel tests and flight and structural test confirmation with two YAV-8B prototypes, the AV-8B entered full scale production as the Harrier II. The first AV-8B squadron stood up in 1985.

The AV-8B was designed primarily to improve upon the performance and handling qualities of the AV-8A/C. It was a new design, with composite structures, a bigger wing, higher engine thrust and reliability, and state-of-the-art avionics; however, it did retain the fundamental single-engine, vectored exhaust nozzle configuration of its predecessor. Where possible, and within tight budgetary and schedule constraints, the prime contractors were also challenged to improve reliability and maintainability (R&M). At the time R&M was a much stronger design driver in the ongoing F/A-18 development program.

As hoped, the flying qualities, performance and warfighting capabilities of the AV-8B proved to be dramatic improvements over those of the AV-8A/C. Although hampered by some significant susceptibility and vulnerability deficiencies, the AV-8B, with its flexible basing, high sortie generation capability and accurate weapon system acquitted itself admirably under combat conditions in the Persian Gulf. However, by the end of 1991, the cumulative (non-combat) mishap rate was disappointingly high at more than 14 per 100,000 flight hours for its first seven operational years.

Early in the Harrier II's career, pilot error and material failures were the major factors in the mishap story; 1990 alone saw the loss of 11 airplanes and two pilots. Of the 15 contributing cause factors in those mishaps, 11 were in the pilot/material categories.

By 1998, USMC Harrier operations (including Naval Air Systems Command) had resulted in 17 fatalities, one permanent disability and 68 AV-8B aircraft lost. With a cumulative Class A mishap rate of 12.1 per 100,000 flight hours, the AV-8B has consistently outpaced all USMC aircraft types in this statistic. It has been the single predominant contributor to the overall Marine aviation mishap story.

AV-8B –408A Engine Upgrade

In FY93 a retrofit program was initiated to replace the Rolls Royce F402-RR-406 Engine in older AV-8B Aircraft with the upgraded F402-RR-408 Engine, which includes a Digital Engine Control System. These retrofits have a planned completion date in FY03. The F402-RR-408 Engine, which powers the Trainer, Night Attack, and Radar aircraft, provides an additional 2000 pounds of thrust and increases the Mean Time Between Engine HSI from 500 to 1000 hours. The F402-RR-408 Engine incorporates modular type design changes in the major engine sections to increase performance, reliability, and maintainability.

The introduction of the –408A engine represented another major safety improvement, arguably as significant as the introduction of the AV-8B itself. The –408 engine provides increased thrust as well as extended life, enhanced reliability of components and important maintainability/supportability features. The engine is designed to exploit the advantages of a modular maintenance concept, Reliability Centered Maintenance (RCM) and an Engine Monitoring System (EMS).

As of 1998 the mishap record of the –408A core engine was impressive. By 1998, approximately 50% of the Marine Corp's single-seat AV-8Bs and six two-seat TAV-8B's were configured with the –408A engine. A Department of Defense (DoD) decision to retrofit all of the TAV-8Bs with the –408A not only provides increased thrust – thereby providing a larger margin for safety - but improves maintainability within the FRS. It also provides an opportunity to establish a common engine for the entire Harrier community. However, some of the important planned maintenance and logistics support features of the new engine had yet to be realized. The EMS was initially only partially fielded, with no usable ground stations for retrieval of data available at the squadron level, and neither the RCM nor the modular maintenance programs had been adequately funded.

T/AV-8B Harrier Trainer Aircraft

The Trainer Aircraft is a fully functional Day Attack Aircraft and can be flown independently from the front seat, or assisted from the back seat. The Trainer Aircraft is used exclusively by the Training Activity.



VMAT-203, MCAS Cherry Point, is the Fleet Readiness Squadron (FRS) Model Manager for aircrew training of the AV-8B. Marine Aircraft Group (MAG)-14 designated VMAT-203 as an assistant Naval Air Training and Operating Procedures Standardization (NATOPS) Model Manager for AV-8B to assist the AV-8B NATOPS Model Manager. AV-8B courseware and TDs have been updated to include the Night Attack and Radar aircraft. AV-8B Pilot training is conducted per the Aviation Training and Readiness Manual. Pilots receive AV-8B familiarization, ground training, and approximately sixty percent of their combat training at the FRS. Pilots continue on to their permanent squadrons to complete combat and qualifications training. Refresher and modified refresher, Category 3 and 4 Pilot training is conducted depending on how long the Pilot has been without AV-8B proficiency training at VMAT-203 FRS, MCAS Cherry Point, and at MAG-13, MCAS Yuma, Arizona.


AV-8B Harrier Night Attack (NA) Aircraft



Introduction of the Night Attack Aircraft in September 1989 significantly enhanced the operating capabilities of the AV-8B by projecting Visual Flight Rules both day and night. In the early 1990s, the Marine Corps installed night capability on 66 of the day-attack version of the AV-8Bs and installed both night capability and an air-to-ground radar on an additional 28 day-attack aircraft.

The Night Attack Harrier improved upon the original AV-8B design through incorporation of a Navigation, Forward-Looking InfraRed (NAVFLIR) sensor, a moving map, night vision goggle compatibility, and a higher performance engine.


AV-8B Harrier II Plus Radar Aircraft

The Radar Aircraft, also known as the Harrier II Plus, was introduced in July 1993 as the newest production AV-8B, achieving Initial Operating Capability in August 1997.


The current Radar/Night Attack Harrier, or Harrier II+, has all the improvements of the Night Attack aircraft plus the AN/APG-65 multi-mode radar. The fusion of night and radar capabilities allows the Harrier to be responsive to the MAGTF's needs for expeditionary, night and adverse weather, offensive air support. The AN/APG-65(V)2 tactical airborne radar system is based on existing specifications for F/A-18 Aircraft; it provides the AV-8B multi-target tracking capability and the ability to perform air-to-air and air-to surface weapons delivery in conditions of marginal visibility, day or night.

In the Radar Aircraft, the AN/APG-65(V)2 Radar System is based on the existing specifications for F/A-18 Aircraft, but tailored for AV-8B missions. Current AV-8B specifications for the radar include a downsized antenna, two modified Shop Replaceable Assemblies (SRA), and commonality with existing items to the maximum extent without compromising performance or mission reliability. The radar modes originally developed in the F/A-18 AN/APG-65(V)2 Radar System were retained, and provide the Radar Aircraft, in conjunction with the Radar Aircraft’s night-attack systems, extended tracking capabilities to perform air-to-air and air-to-surface operations in marginal visibility conditions, day or night. The AN/APG-65(V)2 Radar is a tactical airborne radar system developed by Hughes, Inc.

To remain responsive to fleet needs, older Day Attack AV-8Bs are being remanufactured to the Radar/Night Attack Harrier II+ standard. Plans called for 72 Harriers to undergo remanufacture through FY 2001, reusing major assemblies and components of the Day Attack aircraft in combination with new production structure, systems, and engines. In addition, the Marine Corps was considering remanufacture of an additional 24 aircraft, to be completed by 2003.

The ongoing "remanufacture" program, in which 72 Day Attack aircraft from the existing inventory are being rebuilt to the Radar/ Night Attack standard, extends the service life of these Harrier aircraft into the new century, and greatly improves their warfighting capabilities. Existing Harriers are also being upgraded through the use of commerical off-the-shelf (COTS) technology. The Open Systems-Common Architecture program will replace the existing Harrier mission computer with a COTS system that is affordable and easily upgraded and maintained.

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