Proc. World Aviation Congress (SAE Technical Paper: 2002-1-3013), Phoenix, AZ, November 2002

Aging Aircraft Usable Life and Wear-out Issues

D. Humphrey and D. Lorenson
Honeywell International, Inc.
Tucson, AZ

W. Shawlee, II
Sphere Research Corporation
Kelowna, BC Canada

P. Sandborn
CALCE Electronic Products and Systems Consortium
University of Maryland
College Park, MD 20742


How a system ages is central to the assessment of the effective utilization life of the system. Utilization life represents more than estimating the remaining life in an aged system, it is determining how to optimally plan a system's future management and future use to minimize the life cycle cost incurred. The consideration of utilization life of a system includes the physics of aging, damage accumulation techniques, mitigation of aging, qualified use of aged parts for spare replenishment, prognostics, and quantification of cost avoidance.

Any approach to evaluating utilization life depends on a making an effective evaluation of the reliability, durability and safety of the system. Traditional Mean Time Between Failure (MTBF) metrics that assume a constant failure rate are likely to be less useful in the evaluation and practical implementation of utilization life concepts than Failure Free Operating Period (FFOP). Consideration of the durability related issues of aging hardware and usable life for determining the best time to retire an avionics unit is a key factor in providing uninterrupted, reliable, and safe performance of avionics products.

Complete article is available to CALCE Consortium Members.


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