Durability and damage tolerance control plans for U.S. Air Force aircraft

The U.S. Air Force and Pratt & Whitney Aircraft are currently engaged in developing technology to minimize low-cycle fatigue maintenance requirements in future gas turbine engines. The Life Cycle Cost/Damage Tolerance Assessment (LCC/DTA) program is directed toward furthering technology development in two important areas that relate to the overall life cycle cost of advanced Air Force weapon systems: life cycle cost modeling and analysis, and damage tolerance design (DTD). A major goal of the LCC/DTA program is to establish hot-section disk design criteria specifying acceptable levels for life and maintenance actions based on minimum life cycle cost. This paper discusses the methodology developed to evaluate the weapon system LCC impact of designing to damage tolerance criteria.

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Durability and Damage Tolerance Assessment of the TF34-100 Engine

Volume 2: Aircraft Engine; Marine; Microturbines and Small Turbomachinery ◽

10.1115/86-gt-38 ◽

1986 ◽

Author(s):

Jon S. Ogg ◽

Ronald R. Reinhold

Keyword(s):

Air Force ◽

Damage Tolerance ◽

Flight Safety ◽

Weapon System ◽

General Electric ◽

Structural Assessment ◽

Structural Durability ◽

Inspection Systems ◽

Useful Life ◽

Maintenance Plan

The critical nature of the TF34-100 engine to the Air Force’s A-10 Close Air Support weapon system made it important to obtain the best possible visibility of the engine’s future structural maintenance needs and component life limits. Accordingly, an in-depth structural durability and damage tolerance assessment was performed on this engine by a joint Air Force/General Electric team. Results of the assessment team’s unprecedented analysis efforts culminated in a comprehensive Structural Maintenance Plan that identified both current and future maintenance actions necessary for insuring maximum flight safety. The plan entailed component inspection and replacement intervals, inspection systems, preferred modifications/reworks, and a life growth plan for extending the useful life of the TF34-100 upwards to 8000 A-10 mission hours. This paper details the nature and extent of effort undertaken in conducting the 18 month structural assessment.

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Laser Shock Processing: Applications and Future Trends in U.S. Air Force Service

Volume 7: Operations, Applications, and Components ◽

10.1115/pvp2005-71796 ◽

2005 ◽

Author(s):

M. J. Shepard

Keyword(s):

Air Force ◽

Damage Tolerance ◽

The United States ◽

Foreign Object ◽

Laser Shock ◽

Laser Shock Processing ◽

Current Application ◽

Foreign Object Damage ◽

Us Air Force ◽

Shock Processing

To date, the United States Air Force is the largest end-user of laser shock processing services. Laser shock processing (LSP) is in successful day-to-day service and production for several USAF engine lines for increased foreign object damage tolerance. In this application LSP has yielded substantial increases in foreign object damage tolerance along with associated increases in safety. The history and current application of laser shock processing for US Air Force applications will be reviewed. Current and future USAF applications of laser shock processing and other surface treatments will be reviewed.

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