Hums

Many airlines operating fixed wing aircraft have adopted a pro combat-ready approach to improve operational safety by analyzing flight data on a phone number basis to provide better visibility of their operation In flight operations quality presumption (FAQ) programmer. A simple description of HUMS Is that It Is a system for monitoring the status of technical components, principally shafts, bearings, gears and separate rotating components. The level of palpitation Is recorded by accelerometers. The data is stored in a data card which is later interpreted out and brought too cast anchor station for reading off at the end of for each one flight.Operational information from the flight thus becomes available from the ground station via a terminal. The list thus printed overly informs regarding any limit values that have been exceeded and description of failures in HUMS. Most of the information is analyses manually and this provides worthful additional information during trouble shooting. Advanced helicopter monitoring systems were Implemented In the early sasss side by side(p) concern over the alarm worthiness of helicopters and, at the time, technical defects were the mall Issue.The acronym HUMS, Health and usage monitor Systems, was introduced for these systems. With the introduction of HUM systems, the number of incidents relating to the chemical malfunctions decreased and as a consequence the proportions of incident relating to the air crew error increased. Thus later a need was envisaged of developing a system called HOMO. AIM pass judgment use in aviation and in context to India Air Force. WORKING The system consists of sensors, computers, softwargon and uninflected methods that, when taken in concert be able to record vibration and other parameters and thus deduce the health of the machine.The HUMS information is received and processed by the Digital Acquisition and Processing Unit (ADAPT) before creation stored on a magnetised card which is placed in the cockpit unit prior to flying. This card is taken out on leaving the helicopter after the flight and data argon loaded into a ground station for further electronic processing. A HUMS is like a doctor applying many stethoscopes to a patient continuously and keeping a constant check on his health. Helicopters having more rotating and moving parts, result fall part if not properly maintained, hence their mechanical health is critical to the safety of flight.The deployment of HUMS as a life saving and cost effective equipment is a boon. There are number of electric ray systems in HUMS which determine parameters and determines he health of the helicopters. We will be dealing with the most important subsystems in the subsequent paragraphs. In HUMS the get in or damage to the components is identified while in service itself. needfully components wear out or fail unexpectedly. The traditional monitoring techniques such as oil rubble and engine performances trending are ai med at identifying these problems before they become hazardous.Techniques using conventional flight data endure be employ here, for example, engine performance trends can be calculated from engine parameters gathered 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 health of the rotors and transmission. These rely heavily upon vibration measurement and require special instrumentation and data acquisition systems. A PC based ground station provides the aircraft operator and maintain the simple diagnosis of the aircraft and required maintenance actions.Advanced mechanical of aircraft monitoring brag 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 usage 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 measured in terms of blade height past a fixed point and the angle amidst the resultant 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 trailing edges of the blades can be detected, and the timing of their passes gives the blade eight. The interval between one blade passing over the sensor and the following blades gives the system lead/lag information. infrared radiation techniques can be used if the helicopter is to be flown at night. (b) Engine Monitoring. Engine Monitoring parameters accommodate vibration, gas temperatures and pressures, and shaft speeds. Engine Vibration can indicate excessive wear on puffiness bearings or races.Small changes in the engine vibration signature must be recognized early. Two acce lerometers are used to compile a good engine spectrum. The known frequencies of rotating components can first be used o detect simple imbalance. Then they are subtracted from the known spectrum. The remaining spectral lines are analyze for more subtle defects. Gas temperatures are used to calculate thermal fatigue. High/Low temperature excursions, together with mean temperatures, are used to estimate damage caused by metal expansion and contraction. (c)Gear Box Vibrations.The impressiveness of gearbox vibration monitoring can not be over estimated. Cracks, broken gear dentition 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(prenominal) 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) Oil Debris Monitoring. Any moving metal surfaces in get across with one another will produce debris.Most of it will end up in oil. Therefore, metal instalment detection is a useful means of monitoring wear in the engine and gear box. Particles lesser than ten microns are the result of normal wear and are no cause of concern, unless they are beingness ground down from larger particles. The presence of metal flecks greater than hundred microns in size 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 creation of more large particles.Magnetic plugs were originally introduced to capture debris and thwart secondary damage. Today they have become an early warning device for heavy wear. A enlargement of this is the quantitative debris monitor, which consists of an electronic metal particle detector used in the place of the magnetic plug. The monitor uses an electromagnetic to attract debris. The debris causes a flux distu rbance in the drive coil, which in turn generates a voltage pulse that is proportional to particle size. A processor grades and counts the particles by size.