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Gears are significant component in a multiplicity of industrial applications such as machine tool and gearboxes. An unforeseen failure of gear may result in significant economic losses. Therefore this research propose fault detection improvement throught series of vibration signal processing techuiques. These techniques have been tested experimentally using vibration data collected from the transmission system of a CS-29 ‘Category A’ helicopter gearbox under different bearing damage severity of the second planetary stage. Results showed successful improvement of bearing fault detection. [ABSTRACT FROM AUTHOR]

INTRODUCTION: Attention plays a central role in cognitive processing; ineffective attention may induce accidents in flight operations. The objective of the current research was to examine military pilots'attention distributions between chasing a moving target and a stationary target. METHOD: In the current research, 37 mission-ready F-16 pilots participated. Subjects'eye movements were collected by a portable head-mounted eye-tracker during tactical training in a flight simulator. The scenarios of chasing a moving target (air-to-air) and a stationary target (air-to-surface) consist of three operational phases: searching, aiming, and lock-on to the targets. RESULTS: The findings demonstrated significant differences in pilots'percentage of fixation during the searching phase between air-to-air (M = 37.57, SD = 5.72) and air-to-surface (M = 33.54, SD = 4.68). Fixation duration can indicate pilots' sustained attention to the trajectory of a dynamic target during air combat maneuvers. Aiming at the stationary target resulted in larger pupil size (M = 27,105, SD = 6565), reflecting higher cognitive loading than aiming at the dynamic target (M = 23,864, SD = 8762). DISCUSSION: Pilots' visual behavior is not only closely related to attention distribution, but also significantly associated with task characteristics. Military pilots demonstrated various visual scan patterns for searching and aiming at different types of targets based on the research settings of a flight simulator. The findings will facilitate system designers'understanding of military pilots'cognitive processes during tactical operations. They will assist human-centered interface design to improve pilots'situational awareness. The application of an eye-tracking device integrated with a flight simulator is a feasible and cost-effective intervention to improve the efficiency and safety of tactical training. [ABSTRACT FROM AUTHOR]

INTRODUCTION: The current research was to investigate pilots' visual scan patterns in order to assess attention distribution during air-to-air maneuvers. METHODS: A total of 30 qualified mission-ready fighter pilots participated in this research. Eye movement data were collected by a portable head-mounted eye-tracking device, combined with a jet fighter simulator. To complete the task, pilots had to search for, pursue, and lock on a moving target while performing air-to-air tasks. RESULTS: There were significant differences in pilots' saccade duration (ms) in three operating phases, including searching (M = 241, SD = 332), pursuing (M = 311, SD = 392), and lock-on (M = 191, SD = 226). Also, there were significant differences in pilots' pupil sizes (pixel²), of which the lock-on phase was the largest (M = 27,237, SD = 6457), followed by pursuit (M = 26,232, SD = 6070), then searching (M = 25,858, SD = 6137). Furthermore, there were significant differences between expert and novice pilots in the percentage of fixation on the head-up display (HUD), time spent looking outside the cockpit, and the performance of situational awareness (SA). DISCUSSION: Experienced pilots have better SA performance and paid more attention to the HUD, but focused less outside the cockpit when compared with novice pilots. Furthermore, pilots with better SA performance exhibited a smaller pupil size during the operational phase of lock on while pursuing a dynamic target. Understanding pilots' visual scan patterns and attention distribution are beneficial to the design of interface displays in the cockpit and in developing human factors training syllabi to improve the safety of flight operations. [ABSTRACT FROM AUTHOR]

Acoustics Emissions (AE) technology has emerged as a promising diagnostic approach. AE was originally developed for non-destructive testing of static structures, however, in recent times its application has been extended to health monitoring of rotating machines. This paper introduces a novel method for application of AE in monitoring of helicopter gearboxes. In addition this paper investigates the application of signal separation techniques in detection of bearing faults within the epicyclic module of a large helicopter (CS-29) main gearbox using Acoustic Emissions (AE). The results showed successful of AE in detection bearing fault within the helicopter gearbox. Detection of the small bearing defect gives the AE an indisputable diagnosis advantage and prove ability of application of AE in helicopter gearboxes. [ABSTRACT FROM AUTHOR]