industry TOOLS AND TEST EQUIPMENT Suggestions to minimize risk A S T O R Y B Y E D L E V Y ircraft maintenance personnel and Federal Aviation Administration certificated repair stations make every effort to approve for return to service aircraft and engine components that are airworthy. However, components that are maintained or altered using tools and test equipment that are improperly calibrated, or not equivalent to those prescribed in their component maintenance manuals, may be inadvertently approved for return to service without conforming to their manufacturer-specified tolerances and specifications. This article identifies some of the reasons for this scenario and provides suggestions for minimizing the risk. In case of conflict between the contents of this article and current FAA regulations and guidance, those documents will always take precedence. As you navigate through this topic, it is important to understand the difference between a repair and an alteration. For the purposes of this discussion, a repair is restoring an article to its original or properly altered condition, while an alteration is modifying the article from its original (or properly altered) condition. A repair that requires a modification would be considered an alteration. Title 14 of the Code of Federal Regulations Section 43.13 authorizes the use of equivalent tools and test equipment during maintenance and alterations, and requires that components which are approved for return to service "... must be equal to their original or properly altered condition ..." It is important to understand clearly the meaning of the word "equivalent" in the context of this regulation and the FAA definition of "airworthy." A component is considered airworthy when it conforms to its original type design as well as all previously approved alterations and is in condition for safe operation. 56 avionics news * february 2015