Number: EZ-SB-14-003
Date: 9 April 2014
Subject: Durability Test Programs to Validate Aircraft Structure Service Life
Capability for Repairs, Modifications, and Materials & Processes Changes
References:
1. Department of Defense Standard Practice, MIL-STD-1530C, “Aircraft Structural
Integrity Program”, 1 November 2005.
Background:
Paragraph 5.3.4 in Reference 1 indicates that the full-scale durability test program may
“identify critical areas of the aircraft structure not previously identified by analysis or
component testing” and states “major component modifications which alter the structural
load paths or which represent significant changes in structural concept shall require a
durability test of a full-scale component”. In addition, paragraph 5.3.4.2 in Reference 1
suggests it may be advantageous to continue testing beyond the minimum requirement
to “validate repairs, modifications, inspection methods, and changes”. Finally,
paragraph 5.3.7 in Reference 1 states “structural modifications or changes derived from
the results of the full-scale tests to meet the specified strength, rigidity, damage
tolerance, and durability design requirements shall be substantiated by subsequent
tests of components, assemblies, or full-scale article, as appropriate”. These
requirements should be achieved to the maximum extent practical. However, there are
some cases where it is not practical and therefore subcomponent or lower level of
complexity durability testing may be required to validate the design changes. In
addition, component or higher level of complexity durability testing to evaluate
unexpected cracking or failures in service and validate repair or modification designs
may not be practical. Furthermore, proposed materials & processes changes that
potentially impact the service life capability (e.g. metal cutting, coatings, paint removal)
should include a durability and corrosion, if applicable, test program that includes all
appropriate variables to validate the change prior to implementation.
Structures Bulletin
AFLCMC/EZ
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Phone 937-255-5312
DISTRIBUTION A. Approved for public release; distribution unlimited.
EZ-SB-14-003, Page 1 of 4
