Retirement-for-Cause:

Retire a part when it’s ready, not before.

Nearly all very expensive mechanical components are retired to a schedule to avoid a very low probability of failure. That means an exceedingly large fraction (usually 99.9% – or more) still have considerable useful service life that is wasted by early retirement. RFC is a well-tested maintenance procedure to allow safe use of the full life capacity of each component.

Statistical Engineering Workshop/Short Course Explaining RFC

 

Necessary Technologies

Historically, cyclic life limited gas turbine engine components have been retired when they reached an analytically determined life where the first fatigue crack per 1,000 parts could be expected. By definition, 99.9% of these components are being retired prematurely as they have considerable useful life remaining. Retirement-for-cause is a procedure which would allow safe use of the full life capacity of each component. Since gas turbine engine rotor components are prime candidates and are among the most costly engine components, adopting an RFC maintenance philosophy could result in substantial engine systems life cycle cost savings.

Fracture Mechanics

Two major technical disciplines must be developed and integrated to realize such cost savings: Fracture Mechanics (F/M) and Quantitative NonDestructive Evaluation (QNDE).

This Workshop discusses the RFC methodology and development activity required to integrate these disciplines to provide a viable RFC system for use on vulnerable mechanical systems, and illustrates potential benefits of its application as applied to military gas turbine engines.