Design Improvement by Damage Tolerance Test in Airframe Development

In aircraft development process, several essential tests including flight test should be conducted to validate the performance of aircraft. Ground structural tests for airworthiness certification should be performed in various levels of static and durability tests. This evaluation is intended for the result implementation of design improvement, which provides structural integrity verification according to Test & Evaluation Master Plan. For the life-time testing, a random flight-by-flight spectrum of loads consistent with the design mission profile was applied to the test article under tight control, while all the strain and deflection data were measured and acquired. Through inspection works including both close visual inspection and nondestructive inspection were conducted periodically. All the related discrepancies between analysis and test results, which were found in the inspection, have been evaluated for prompt assessment. The required design improvement action could be made, soon after the fractographic analysis results were available.