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Ensuring the reliability of complex software intensive systems is becoming a critical requirement for all military and commercial aerospace applications, and becomes especially more challenging when implemented for autonomous and evolving deployments required of such applications. To ensure reliability, this research asserts that knowledge, data, and models(More)
In this paper, we present the current state of a failure mode taxonomy, and discuss its potential to explore the failure mode space of aerospace applications. More fundamentally, we discuss what constitutes a good description of a failure that can be detected at the conceptual design stage. Elemental (physics-based) descriptions of failure modes are derived(More)
Statistical analyses of transmission vibration patterns from an AH-1 Cobra helicopter were previously reported. Fourteen steady-state maneuvers were analyzed using multi-factor analysis of covariance. Based on triaxial recordings, it was found that only two maneuvers displayed reliably stationary time-series: low and high power forward climb. Principal(More)
Detection of faults is a continuing need in all manufacturing processes. This need is more pronounced in new manufacturing processes where continual product improvement is desired. In this paper, a systematic approach is developed for addressing this need. Contemporary experimental and surface analysis techniques provide a basis for incrementally diagnosing(More)
Research on the nature of the vibration data collected from helicopter transmissions during flight experiments has led to several crucial observations believed to be responsible for the high rates of false alarms and missed detections in aircraft vibration monitoring systems. This work focuses on one such finding, namely, the need to consider additional(More)
Communicating failure mode information during design and manufacturing is a crucial task for failure prevention. Most processes use Failure Modes and Effects types of analyses, as well as prior knowledge and experience, to determine the potential modes of failures a product might encounter during its lifetime. When new products are being considered and(More)
During the past several years, an AH-1 Cobra aircraft at the NASA Ames Research Center has been instrumented with tri-axial accelerometers and a data acquisition system to support the experimental study of in-flight transmission vibration patterns. This paper describes the on-board HealthWatch system and presents important statistical analyses of the(More)
During the past several years, an AH-1 Cobra aircraft at the NASA Ames Research Center has been instru-mented with tri-axial accelerometers and a data acquisition system to support the experimental study of in-flight transmission vibration patterns. This paper describes the on-board HealthWatch system and presents some important initial statistical analyses(More)
Complex aerospace systems are often designed in collaborative engineering environments where requirements and design decisions are rapidly made and withdrawn by various subsystems as the process evolves. As a result, the system-level management should continuously re-allocate resources (e.g. capital and labor) among various subsystems such that the main(More)
As part of a collaborative research program betweentory, a series of experiments is being performed in GRC's 500 HP OH-58 Transmission Test Rig facility and ARC's AH-1 Cobra and OH-58c helicopters. The findings reported in this paper were drawn from Phase-1 of a two-phase test-rig experiment, and are focused on the vibration response of an undamaged pinion(More)