36002207-7-Indicating - ATA -31 INDICATNG AND RECORDING...

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Unformatted text preview: ATA -31 INDICATNG AND RECORDING SYSTEMS A/c has many systems functioned by electricity in these modern days. The condition of the systems like satisfactory function, functioning in a partially serviceable state and failure of the stem are required to be indicated to pilot, this is accomplished by different colored lights within standardized specifications, i.e. these light are broadly divided into three different categories according to the function they problem. They are warning lights caution lights, indicating or advisory lights. Warning lights: Red colored and are for indicating failure of a system as well as to alert the flight crew of an unsafe condition. Power supply or these light is DC and the power is derived from the another busbar different from those feeding the system which is failed, because if the system failure is due to the loss of power from the busbar. Testing facility to check the serviceability of lamp filaments is provided with a separate switch or press to test switch is provided for testing purpose of lamp filaments without operating the system during preflight checks. Construction:A casing with electrical connection, which can house a lamp filament i.e. a clear or white and a colored lens, fitted in the cap. Caution light: Similar in construction to warning lights. Amber in color for giving an abnormal or partial serviceable condition but not a dangerous situation. Eg: Hydraulic system pressure is running low. Indicating lights: Blue or green to indicate satisfactory & safe operation. Eg: Landing gear extended & locked. General features: A dimming facility for lamp filaments is provided to avoid glare to the pilot as many indicating lights are illuminated in the cockpit. The dimming is obtained by suitably placing a variable resistance in series or an Iris type diaphragm with opening or closing mechanism is provided. However red warning light are not connected with dimming facility. Power supply: D.C power A.C power is also used in association with step down transformer warning lights are powered from another bus bar from that of the bus bar connected to they are also given power similar to warning lights. Magnetic indicators: In an a/c the electrical power is consumed by many systems or components & indication for these satisfactory functions is required most vital systems like fuel system i.e. fuel from main tanks to engine & cross feeding. Another important area is actuator operating. Valve controls etc. are provided with switch controls & completion of their operation is confirmed by indications. In general indications can be provided by a scale & pointer type instrument. An indicator lamp But, the both has some disadvantages i.e. in case of  Space consuming,  Fusing of lamp filament, many cause confusion & glaring. Operation of two-position indicator: I/p supply is similar to light indicator. When coil is energized, the core becomes magnetized and a force of attraction is exacted on the armature, which enables the ball to rotate to 150° against the retaining spring tension, & represents in the form of like diagram or in structure signs. Operation of-three-position indicator: This indication provides three alternative indications Two electromagnets are incorporated & can be attracted by any one EM. Magnetic influence tills the armature, which in turn slide the actuating arm, which enables sliding of the prison horizontally to have a rotation of 120° and provides an indication. The operation is with the combination of retaining spring & electromagnet. Central Warning system: Consequent to technological development and introduction of many systems for betterment of the flight safety & passenger comfort, an accurate indication system is mandatory in order to confirm the satisfactory function of the systems. The indicating lights or instruments consume lot of space. The entire warning cautionary / indicating systems have been centralized which is called central warning system in the modern A/c. Basic form of C.W.S: Basically the warning/indicating system is at OHP (over head panel) in order to bring the systems operating conditions to notice by pilot is accomplished by a group of indicator lights, a master warning light & master caution light accommodated on a anti glass shield placed infront of the pilot in the instrument panel of the cockpit. The anti fare panel consists very few blue lights & remaining are amber & red lights with one master caution & master warning lights. Operation / Activation method: Upon occurrence of a fault, an amber indication for the system concerned is illuminated in the OHP, simultaneously appropriate to the system legend, the amber indication & master caution light will be illuminated. This is achieved by a fault pulser & SCR circuitry placed b/w OHP & CWS. Pilot after noticing of a fault, the indication on the CWS can be switched off by pressing the MCL (Master Caution Light) & MW (Master warning light) are press to reset type. C.W.S for a flight engines: AURAL WARNING SYSTEM - GENERAL DESCRIPTION General The aural warning module is the only component in the aural warning system. System monitor circuits detect incorrect system conditions and flight crew alerts. The monitor circuits supply discrete signals to the aural warning module. Inputs These are the discrete inputs to the aural warning system: Unsafe landing warning Unsafe takeoff warning Cabin pressure warning Autopilot disengage Over-speed warning Fire warning Crew call. Sounds The aural warning module gives these sounds in the flight compartment:  Fire bells  Chimes  Over-speed clackers  Wailer  Continuous horn  Intermittent horn. NOTE: This section only describes in general the types of warnings available in the 737NG. More detailed descriptions and functions are described in the particular system-description. (Example: fire bell is described in chapter 26-fire warning system). MASTER CAUTION SYSTEM - INTRODUCTION General The purpose of the master caution system is to inform the flight crew that system warning lights, located behind pilots or out of view of the captain and copilot, are illuminated. Example: With a hydraulic low-pressure light illuminated, (which is located on the aft overhead panel and therefore out of view of the pilots), on the glare shield the system annunciator HYDR and both MASTER CAUTION lights will illuminate. Reset of master caution lights: o Press captains or copilots master caution light. Master caution lights and master caution system annunciator lights will extinguish, Recall of the master caution lights: Press any master caution six-pack, If pilots want to know if there is still a system warn-light out of their illuminated and pilots don't want to turn their heads to see it, they simply press one of the master caution system annunciators. Six pack lights whose system warns light is still on will illuminate again. Six-pack system lights will illuminate. MASTER CAUTION SYSTEM - GENERAL DESCRIPTION The following should give a very general about the master caution system only! What we want to point out is:  Master Caution is not a centralized system with a, big black box downstairs.  Master Caution is individually integrated in the individual system module or panel,  The panel triggers the master caution lights and the system lights in the master caution annunciator (commonly called, six-pack),  So according to which system light illuminates together with the master lights, the crew knows from the beginning, which system malfunctions.  The master caution reset, by pressing a master caution light, is achieved in the system module (flight control module, fuel module, elec. module and so on).  The master caution recall, by pressing a master caution system six-pack, is also done in the system module.  To operate a system, for example a fuel pump including its warning, there are at least 4 circuit breakers are necessary. Power reduncy not included. The circuit breakers are (example fuel pump):  Fuel pump CB  MASTER CAUTION ANNUNCIATOR CONT 1 CB (for the Fuel Module)  SECT (for the system module annunciator lights)  At least one MASTER CAUTION ANNUNCIATOR CB Please keep in mind, that each individual system controls its master caution by its module. ...
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