'Hums\r'

'Many airlines operating quick-frozen wing aircraft birth adopted a master active approach to improve operational rubber eraser by analyzing flight info on a routine basis to provide better profile of their operation In flight operations flavour Assurance (FAQ) programmer. A simpleton description of HUMS Is that It Is a constitution for observe the status of technical comp atomic number 53nts, primarily shafts, bearings, gear mechanismed wheels and other rotating components. The level of trembling Is recorded by accelerometers. The data is stored in a data carte du jour which is later taken out and brought too grime station for reading off at the finish of each flight.Operational study from the flight olibanum exits accessible from the ground station via a terminal. The list thus printed also informs regarding any limit values that watch been exceeded and description of smashures in HUMS. Most of the information is analyses manually and this provides valu adequate to(p) additional information during trouble shooting. sophisticated eggbeater remindering systems were Implemented In the former(a) sasss following concern over the alarm virtuousness of pearlys and, at the time, technical defects were the mall Issue.The acronym HUMS, Health and utilisation supervise Systems, was introduced for these systems. With the introduction of HUM systems, the telephone number of sequents relating to the chemic malfunctions decreased and as a consequence the proportions of incident relating to the aircrew error increased. Thus later a need was envisaged of developing a system called HOMO. draw accepted use in aviation and in context to India Air Force. WORKING The system consists of sensors, computers, bundle and analytical methods that, when taken together ar able to record vibration and other parameters and thus subtract the wellness of the machine.The HUMS information is received and processed by the Digital Acquisition and Processing Unit (A DAPT) in the first say being stored on a magnetic handbill which is placed in the cockpit unit prior to flying. This banknote is taken out on leaving the helicopter after the flight and data be irritated into a ground station for further electronic processing. A HUMS is like a doctor applying many an(prenominal) stethoscopes to a patient continuously and keeping a constant check on his health. Helicopters having more rotating and lamentable parts, will fall part if not correctly maintained, hence their mechanical health is slender to the golosh of flight.The deployment of HUMS as a life saving and exist effective equipment is a boon. There be number of sub systems in HUMS which determine parameters and determines he health of the helicopters. We will be dealing with the most burning(prenominal) subsystems in the subsequent paragraphs. In HUMS the wear or violate to the components is identified while in assistance itself. Inevitably components wear out or fail unexpe ctedly. The traditional monitoring techniques such as fossil oil debris and engine exploits trending ar aimed at identifying these problems before they become hazardous.Techniques using conventional flight data abide be used here, for example, engine performance trends can be calculated from engine parameters collected in flight. Still the traditional Accident data is usually inadequate for monitoring wear in rotating components and so a host of specialized techniques have been developed to measure the â€Å"health” of the rotors and transmission. These rely firmly upon vibration measurement and require special orchestration and data acquisition systems. A PC ground ground station provides the aircraft operator and maintain the simple diagnosis of the aircraft and required maintenance actions.Advanced mechanical of aircraft monitoring superior to any other monitoring system available. THE SUB SYSTEMS As stated earlier there are number of sub systems which gather information in flight bout the health and recitation and wear and tear off the components and can be read over a ground station. major ones are:- (a) Rotor Track and Balance. Each helicopter main rotor blade should follow one in front and along the same path, and blades should be spaced at equal angles. This track is measurable in terms of blade height foregone a fixed point and the angle amongst the successive blades.A photo sensitive device on the nose looks at the blade tips at two points on the either side of the nose. The leading and the tracking edges of the blades can be detected, and the timing of their passes gives the blade eight. The separation between one blade passing over the sensor and the following blades gives the system lead/ dally information. Infrared techniques can be used if the helicopter is to be flown at night. (b) Engine Monitoring. Engine Monitoring parameters include vibration, gas temperatures and pressures, and shaft speeds. Engine vibe can ind icate excessive wear on ball bearings or races.Small changes in the engine vibration signature must be recognized early. two accelerometers are used to compile a high-priced engine spectrum. The known frequencies of rotating components can first be used o detect simple imbalance. thence they are subtracted from the known spectrum. The remaining spectral lines are analyzed for more subtle defects. Gas temperatures are used to calculate thermal fatigue. High/ gloomy temperature excursions, together with mean temperatures, are used to hazard damage caused by coat expansion and contraction. (c)Gear street corner Vibrations.The importance of gearbox vibration monitoring can not be over estimated. Cracks, broken gear teeth and excessive wear are critical areas that must be caught early. Gear vibrations are revealed by strategically positioned accelerometers. There might be 20 shafts in the gear box but fewer than half this number of accelerometers are needed to monitor them all. The problem is to separate very small signals caused by a single tooth defect from larger signals (d) anoint Debris Monitoring. Any moving metallic element surfaces in contact with one another will begin debris.Most of it will end up in oil. Therefore, metal particle detection is a useful doer of monitoring wear in the engine and gear box. Particles lesser than ten microns are the result of commonplace wear and are no cause of concern, unless they are being ground down from larger particles. The straw man of metal flecks greater than hundred microns in surface indicates a serious wear problem. Particles that size are large enough to cause further damage to other parts of the engine, which in turn leads to inception of more large particles.Magnetic plugs were originally introduced to capture debris and prevent secondary damage. Today they have become an early warning device for heavy wear. A refinement of this is the quantitative debris monitor, which consists of an electronic met al particle detector used in the place of the magnetic plug. The monitor uses an electromagnetic to attract debris. The debris causes a flux disturbance in the causal agent coil, which in turn generates a voltage metre that is proportional to particle size. A processor grades and counts the particles by size.\r\n'