Accession Number:

ADA066596

Title:

The Influence of Fleet Variability on Crack Growth Tracking Procedures for Transport/Bomber Aircraft

Descriptive Note:

Final technical rept. 1 Nov 1976-1 Jun 1978

Corporate Author:

BOEING WICHITA CO KS

Personal Author(s):

• Bryan, David F.
• Lambert, Gordon E.

Report Date:

1978-11-01

Pagination or Media Count:

208.0

Abstract:

The purpose of this program is to provide generalized crack growth tracking procedures for transportbomber aircraft. The study was composed of three major tasks, 1 an evaluation of the effects of usage parameters on crack growth, 2 the development of generalized tracking procedures and 3 an evaluation of the techniques for implementing the individual aircraft tracking program. The KC-135A tanker was selected as the baseline aircraft for this study. Approximately thirty tests were conducted to experimentally verify predictions made from analyses and to determine the crack growth rate characteristics of the specimen material. The results of the parametric and variability studies were used to develop analysis schemes for predicting the effects of usage variations on crack growth. Four tracking procedures were evaluated 1 pilot logs with the use of parametric crack growth rate data, 2 pilot logs with the use of parametric stress exceedance data, 3 the Mechanical Strain Recorder MSR and 4 the crack growth gauge. The implementation of each tracking procedure was evaluated by developing a cost model to study relative life cycle costs.

Descriptors:

• *CRACK PROPAGATION
• *AIRFRAMES
• *BOMBER AIRCRAFT
• *TRANSPORT AIRCRAFT
• STRESS STRAIN RELATIONS
• PARAMETRIC ANALYSIS
• DETECTION
• LIFE CYCLE COSTS
• RETARDATION
• TOLERANCES(MECHANICS)
• RECORDING SYSTEMS
• DATA ACQUISITION
• PREDICTIONS
• DAMAGE ASSESSMENT
• TEST METHODS

Subject Categories:

• Bombers
• Transport Aircraft
• Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE