Universal Synaptics’ Intermittent Fault Detection (IFD) technology was recently featured in 2021 CTMA Magazine Issue #9 in an article entitled Joint Intermittence Testing (JIT) Working Group by Dana Ellis, Senior Program Manager for the National Center of Manufacturing Sciences (NCMS).
Mr. Ellis states that a DoD group called the JIT “has been instrumental in shaping the strategic and tactical activities required to identify diagnostic equipment capable of detecting intermittent faults. Through the JIT WIPT collaboration, the Military Services concluded that Intermittent Fault Detection Equipment standardization is critical to address electronics component failures.” He continues, stating “the project team identified and validated test methods for ensuring specified minimum performance requirements for detecting and isolating intermittence are met according to the MIL-HDBK-527 and [the proposed insertion into] MIL-HDBK-454 Intermittent Fault Diagnosis Guideline.
“The accomplishment that best illustrates the JIT WIPTʼs effectiveness in terms of technical competence, government and industry collaboration, and action orientation is the publication of MIL-PRF-32516 Electronic Test Equipment, Intermittent Fault Detection and Isolation for Chassis and Backplane Conductive Paths in March 2015. It formally recognized intermittence as a DOD-recognized failure mode and addressed the intermittent fault capability gap. This specification defined the minimum performance requirements for equipment to detect and isolate nanosecond, microsecond, and millisecond conductive paths and intermittent faults. These can occur in all the hundreds to thousands of Line Replaceable Unit/Weapons Replaceable Assembly (LRU/WRA) chassis and backplane circuits and their wiring harnesses in the DODʼs equipment. Prior to this publication, no specification or standard existed to remediate these intermittent fault problems.”
“DOD maintenance operations sustain and restore weapon systems and materiel to inherent performance, safety, and reliability levels. Maintenance generates and sustains materiel readiness, ensuring weapon systems, equipment, and platforms are available to support training and exercises, and ultimately, to deploy in support of warfighter requirements to respond to any humanitarian or contingency situation. Roughly $95 billion of DODʼs total FY19 expenditure was applied to maintenance activities and services with aircraft maintenance being the greatest expenditure at approximately $32 billion. Electronics maintenance, a leading driver of weapon systems non-availability, accounted for over $12 billion in FY19 maintenance costs. Intermittent electronics failures continue to be a leading contributor to DODʼs $3 billion annual No Fault Found (NFF) problem, unnecessarily consuming 25 percent of the electronics maintenance budget. Many aircraft maintenance issues are directly related to interconnectivity problems on the Electrical Wiring Interconnect System (EWIS), within electronic components, or assemblies. Intermittent faults are mechanical in nature and can include failures in solder joints, wiring, wire wraps, connectors, etc., which manifest as operational failures due to temperature, vibration, and other external environmental stimuli. Hard failures, where wiring issues are evident, are relatively routine to detect and repair. Major electrical issues and critical down-line failures may occur when an electrical fault appears only intermittently, on multiple conductive paths in short duration, under operational conditions (such as high G-force loading and extremes in temperature or stress, or vibrational states) that are difficult to replicate during ground testing and maintenance. The duration of these intermittent events can range from nanoseconds to seconds, and may oscillate repeatedly during an event or a single occurrence during a given testing session. These circuit path disruptions often cause operationally evident functional failures/faults in LRU/WRA chassis and backplanes whose root cause(s) cannot be detected and isolated using conventional Automatic Test Equipment (ATE) and troubleshooting processes. Intermediate and depot maintenance actions, such as the reseating of a degraded connection, solder joint, etc., can temporarily cause the intermittent connection to function properly for days, or even weeks after, and may only manifest as a repeat operational failure after several months.”
“This situation results in a revolving cycle for EWIS and the LRU/WRA removal, maintenance and testing resulting in NFF, and subsequent reinstall on aircraft. Additionally, considerable preventive and corrective DOD electronics maintenance costs are applied to this issue. Even while these resources are consumed, LRU/WRA and system wiring with intermittent faults become known as the Servicesʼ “bad actors” and are repeatedly
sent to DOD and commercial repair facilities, but the current intermittent test equipment void prevents accurate problem diagnosis. In many instances, this leads to unnecessary condemnation of weapon systems components. One main symptom of an Intermittent Fault Failure (IFF) mode problem is a high rate of Cannot Duplicate (CND or A-799), NFF, No Trouble Found (NTF), and Re-test OK (RETOK) reported by the maintenance activities. Diagnostic equipment having the capability to monitor all conductive paths simultaneously and continuously while simulating the specified Type/Model/Series (TMS) operating environment, while not yet widely available, has been identified as an excellent objectively proven solution. Intermittence, while persistent and pervasive, has gained traction and is emerging as an accepted failure mode within the DOD. It is characterized by decreasing reliability and time-on-wing (TOW) and has been conclusively identified as a major contributor to NFF costs and decreased materiel availability. The DOD now operates approximately 400 types of traditional diagnostic test systems valued at $50 billion. However, these test systems do not continuously and simultaneously test all conductive paths. They have very limited or no capability to detect and isolate intermittent faults or reduce NFF costs.”
This article highlights Universal Synaptics’ IFDIS, Intermittent Fault Detection & Isolation System 2.0 (IFDIS 2.0), and the Portable Intermittent Fault Detector (PIFD). IFDIS 2.0 and PIFD increase maintainers ability to accurately troubleshoot intermittent faults. IFD technology is the only objectively proven technology that meets MIL-PRF-32516, reducing maintenance costs, improving component reliability, and increasing materiel readiness in aircraft, ships, ground vehicles, etc.
Read the full article – 2021 CTMA Magazine – Issue Nine – Joint intermittence Testing (JIT) Working Group