protection system book 2

Question 1

fire detection systems on aircraft usually consist of ___ separate operating systems with associated controls and indicators. one system is for fire of overheat _________ and the other is for fire __________ or ___________

Answer 1

fire detection systems on aircraft usually consist of TWO separate operating systems with associated controls and indicators. one system is for fire of overheat DETECTION and the other is for fire SUPPRESSION or EXTINGUISHING_

Question 2

the requirements for fire protection for aircraft are set out in CS__

for example, sufficient fire detectors must be fitted in each designated fire zone and in the _________, _______ and ________ sections of turbine engine installations

Answer 2

the requirements for fire protection for aircraft are set out in CS25

for example, sufficient fire detectors must be fitted in each designated fire zone and in the COMBUSTION, TURBINE and TAILCONE sections of turbine engine installations

Question 3

a designated fire zone is a region where a potential ____ ____ may exist following a _______ or _______ of any component, equipment or part of the power unit

Answer 3

a designated fire zone is a region where a potential FIRE RISK may exist following a FAILURE or LEAKAGE of any component, equipment or part of the power unit

Question 4

• detection systems must be capable of providing _____ detection of _________ fire or overheat conditions and a warning by means of a ___ light and an _______ signal on the flight deck indicating the area where some corrective action is required
• fire detection systems will not automatically operate the main _____ unit extinguishers. however, in some installations, the fire detection system may be used to shut down the ___ and may operate an APU fire extinguisher automatically
• the system must accurately indicate that a fire has been ___________ and indicate if a fire ________

Answer 4

• detection systems must be capable of providing RAPID detection of LOCALISED fire or overheat conditions and a warning by means of a RED light and an AUDIBLE signal on the flight deck indicating the area where some corrective action is required
• fire detection systems will not automatically operate the main POWER unit extinguishers. however, in some installations, the fire detection system may be used to shut down the APU and may operate an APU fire extinguisher automatically
• the system must accurately indicate that a fire has been EXTINGUISHED and indicate if a fire REIGNITES

Question 5

DIFFERENTIAL EXPANSION SWITCH

this is also a point detector. it operates on the principle of the difference in the co-efficent of _______ expansion between different metals (usually _____ and _____) the sensitive bi-metallic strip opens its contacts when the __________ reaches an abnormally high threshold and sends a signal to the flight compartment warning system.

during a ____ temperature rise the insulated bi-metallic strip receives just as much heat as the unclad bi-metallic strip in spite of its insulation. both metallic strips are distorted to the same extent. once the detection threshold is reached, the clad bi-metallic strip contacts the ____, whereas the unclad bimetallic strip continues to be distorted. the contacts will then be separated.

during a rapid temperature rise, the bare metallic strip, which receives more heat than the clad strip is distorted ____ quickly. once the detection threshold is reached, the contacts are separated ______ the clad strip reaches its stop.

Answer 5

DIFFERENTIAL EXPANSION SWITCH

this is also a point detector. it operates on the principle of the difference in the co-efficent of LINEAR expansion between different metals (usually INVAR and STEEL) the sensitive bi-metallic strip opens its contacts when the TEMPERATURE reaches an abnormally high threshold and sends a signal to the flight compartment warning system.

during a SLOW temperature rise the insulated bi-metallic strip receives just as much heat as the unclad bi-metallic strip in spite of its insulation. both metallic strips are distorted to the same extent. once the detection threshold is reached, the clad bi-metallic strip contacts the STOP, whereas the unclad bimetallic strip continues to be distorted. the contacts will then be separated.

during a rapid temperature rise, the bare metallic strip, which receives more heat than the clad strip is distorted MORE quickly. once the detection threshold is reached, the contacts are separated BEFORE the clad strip reaches its stop.

Question 6

RESISTANCE TYPE CONTINUOUS LOOP DETECTORS

the resistance of the insulating material ________ with an increase in temperature

under normal ambient conditions, only a very ______ standing current passes through the separating material. the current passed is __________ to operate the control system. as the temperature __________, the resistance of the filling material __________ as it has an ________ co-efficient of resistance. this will allow more current to pass to the control unit. when the temperature has risen above a pre determined level, sufficient current will pass to operate the warning circuit. a ___ light and a bell indicate a fire

with this arrangement the warning system is not compromised should a _____ occur in the loop

when the test switch is set to the ‘test’ position, the test relay is _________ and its contacts change over the supply from the rectifier so that the current passes directly along the centre electrode

the _____ type of sensing element assembly consists of a ____ of sensing elements mounted on a pre-shaped, rigid _______ tube. the sensing elements are held in place by dual clamps riveted to the tube assembly approximately every __cm (6in)

in the ______ sensing element, an the earth wire is _________ to the tube

Answer 6

RESISTANCE TYPE CONTINUOUS LOOP DETECTORS

the resistance of the insulating material decreases with an increase in temperature

under normal ambient conditions, only a very SMALL standing current passes through the separating material. the current passed is INSUFFICIENT to operate the control system. as the temperature INCREASES, the resistance of the filling material DECREASES as it has an INVERSE co-efficient of resistance. this will allow more current to pass to the control unit. when the temperature has risen above a pre determined level, sufficient current will pass to operate the warning circuit. a RED light and a bell indicate a fire

with this arrangement the warning system is not compromised should a BREAK occur in the loop

when the test switch is set to the ‘test’ position, the test relay is ENERGISED and its contacts change over the supply from the rectifier so that the current passes directly along the centre electrode

the KIDDE type of sensing element assembly consists of a PAIR of sensing elements mounted on a pre-shaped, rigid SUPPORT tube. the sensing elements are held in place by dual clamps riveted to the tube assembly approximately every 15cm (6in)

in the KIDDE sensing element, an the earth wire is SOLDERED to the tube

Question 7

CAPACITANCE TYPE CONTINUOUS LOOP DETECTORS

the element forms a capacitor, the capacitance of which _________ with increased temperature.

the stored charge _________ with the increase in temperature and, when the warning temperature is reached, the ____ current is sufficient to operate a relay in the warning circuit. the main advantage of the capacitance system is that a _____ circuit grounding the element of wiring does not result in a false fire ________

Answer 7

CAPACITANCE TYPE CONTINUOUS LOOP DETECTORS

the element forms a capacitor, the capacitance of which INCREASES with increased temperature.

the stored charge INCREASES with the increase in temperature and, when the warning temperature is reached, the BACK current is sufficient to operate a relay in the warning circuit. the main advantage of the capacitance system is that a SHORT circuit grounding the element of wiring does not result in a false fire WARNINGS

Question 8

APU FIRE AND ENGINE OVERHEAT AND FIRE INDICATIONS

APU fire indication is by ___ lights and a fire ____. a fault in the APU detector is indicated by an _____ light.

an engine overheat indication is by _____ lights. a fire indication is by ___ lights and a fire alarm ____. a fault in the engine fire detector is indicated by an ______ light.

pushing either ____ ____ light or the bell ___ ___ switch puts out the FIRE WARN lights on the glare shield and stops the bell

Answer 8

APU FIRE AND ENGINE OVERHEAT AND FIRE INDICATIONS

APU fire indication is by RED lights and a fire BELL. a fault in the APU detector is indicated by an AMBER light.

an engine overheat indication is by AMBER lights. a fire indication is by RED lights and a fire alarm BELL. a fault in the engine fire detector is indicated by an AMBER light.

pushing either FIRE WARN light or the bell CUT OUT switch puts out the FIRE WARN lights on the glare shield and stops the bell

Question 9

MAIN WHEEL OVERHEAT DETECTION

large transport aircraft are fitted with firewire detectors in the main wheel wells to sense high temperature caused by __________ _____.

when the fire detector senses a temperature of approximately ___ degrees celsius in the wheel well, warning lights illuminate and a fire alarm bell sounds on the flight deck

Answer 9

MAIN WHEEL OVERHEAT DETECTION

large transport aircraft are fitted with firewire detectors in the main wheel wells to sense high temperature caused by OVERHEATED BRAKES.

when the fire detector senses a temperature of approximately 200 degrees celsius in the wheel well, warning lights illuminate and a fire alarm bell sounds on the flight deck

Question 10

DIGITAL FIRE DETECTION SYSTEM OPERATION

the control unit ___________ monitors the _________ and __________ of the firewire element, the characteristics of which change with a rise in temperature

the control unit applies a ______ wave reference signal to the fire wire detector loop. in the event of a fire or overheat, the rise in temperature will cause the _____ of the returned waveform to change. digital techniques are employed to determine when the resistance and capacitance have reached pre-set threshold levels and the control unit will produce an _____ or fault output

Answer 10

DIGITAL FIRE DETECTION SYSTEM OPERATION

the control unit CONTINUOUSLY monitors the RESISTANCE and CAPACITANCE of the firewire element, the characteristics of which change with a rise in temperature

the control unit applies a SQUARE wave reference signal to the fire wire detector loop. in the event of a fire or overheat, the rise in temperature will cause the SHAPE of the returned waveform to change. digital techniques are employed to determine when the resistance and capacitance have reached pre-set threshold levels and the control unit will produce an ALARM or fault output

Question 11

FIRE DETECTOR FITTINGS

note that the split in the ________ should be installed at the _____ side of the radius of the ____ in the fire wire

Answer 11

FIRE DETECTOR FITTINGS

note that the split in the GROMMET should be installed at the OUTER side of the radius of the BEND in the fire wire

Question 12

PNEUMATIC TYPE CONTINUOUS LENGTH FIRE DETECTOR (SYSTRON-______)

if a fire occurs anywhere along the sensing element, there will be a rapid rise in temperature. the centre wire in the tube will now release a large quantity of ________ gas. this will increase the total gas pressure in the tube and will close the second __________ switch. this is called the _______ function of the sensor.

when a fire is extinguished and the temperature begin to drop, the specially processed titanium wire in the tube will reabsorb the __________ gas. this will ________ the pressure in the tube and cause a pneumatic switch to _____. the system will now return to normal and will provide another signal if fire restarts

the responder contains three diaphragm switches. two of the switches are normally ____. one of the switches will close when there is a general ________ along the length of the sensor tube. the second switch will close due to the higher pressure which results from a ____ occurring at any point along the length of the sensor tube. the ________ pressure switch is held closed by he normal ______ pressure on the sensor tube. when the sensor tube is damaged, allowing the helium gas to leak, the integrity pressure switch opens, activating a fault signal

Answer 12

PNEUMATIC TYPE CONTINUOUS LENGTH FIRE DETECTOR (SYSTRON-DONNER)

if a fire occurs anywhere along the sensing element, there will be a rapid rise in temperature. the centre wire in the tube will now release a large quantity of HYDROGEN gas. this will increase the total gas pressure in the tube and will close the second PNEUMATIC switch. this is called the DISCRETE function of the sensor.

when a fire is extinguished and the temperature begin to drop, the specially processed titanium wire in the tube will reabsorb the HYDROGEN gas. this will DECREASE the pressure in the tube and cause a pneumatic switch to OPEN. the system will now return to normal and will provide another signal if fire restarts

the responder contains three diaphragm switches. two of the switches are normally OPEN. one of the switches will close when there is a general OVERHEAT along the length of the sensor tube. the second switch will close due to the higher pressure which results from a FIRE occurring at any point along the length of the sensor tube. the INTEGRITY pressure switch is held closed by he normal HELIUM pressure on the sensor tube. when the sensor tube is damaged, allowing the helium gas to leak, the integrity pressure switch opens, activating a fault signal

Question 13

INFRA RED FIRE DETECTION SYSTEM

early infra-red systems suffered from a lack of discrimination between sunlight and firelight. consequently, opening an engine bay panel would set off the fire alarms. now, newer systems have been modified to tighten the __________ over which these units work

Answer 13

INFRA RED FIRE DETECTION SYSTEM

early infra-red systems suffered from a lack of discrimination between sunlight and firelight. consequently, opening an engine bay panel would set off the fire alarms. now, newer systems have been modified to tighten the WAVELENGTHS over which these units work

Question 14

SMOKE DETECTOR USING A PHOTO ELECTRIC CELL

the smoke detector unit consists of a beacon lamp, a test lamp, a labyrinth and a photoelectric cell. during normal operation, light from the beacon lamp cannot fall on to the photo electric cell. however, when _____ is drawn through the labyrinth, light from the bacon lamp is _________ and can reach the photoelectric cell. this changes the resistance of the photoelectric cell and changes the flow of ________ through it. this change is current flow actuates the amplifier and produces the visual and aural warning signals.

during a smoke detection system test, the test lamp is connected in ______ with the beacon lamp. light from the test lamp shines directly on the photoelectric cell. doing a system test checks the _________ of the smoke detector system and the _________ of the beacon lamp

Answer 14

SMOKE DETECTOR USING A PHOTO ELECTRIC CELL

the smoke detector unit consists of a beacon lamp, a test lamp, a labyrinth and a photoelectric cell. during normal operation, light from the beacon lamp cannot fall on to the photo electric cell. however, when SMOKE is drawn through the labyrinth, light from the bacon lamp is SCATTERED and can reach the photoelectric cell. this changes the resistance of the photoelectric cell and changes the flow of CURRENT through it. this change is current flow actuates the amplifier and produces the visual and aural warning signals.

during a smoke detection system test, the test lamp is connected in SERIES with the beacon lamp. light from the test lamp shines directly on the photoelectric cell. doing a system test checks the INTEGRITY of the smoke detector system and the CONTINUITY of the beacon lamp

Question 15

CONTINUOUS ELEMENT DETECTOR SYSTEMS

• the element should be clipped o the structure every _ inches from end fittings and at approximately _ inch intervals along its length
• function tests - test circuits are usually arranged to _______ fault conditions by either _________ the centre electrode of the element (resistance type) or introducing additional __________ into the circuit (capacitance type). reference should be made to the relevant maintenance manual

Answer 15

CONTINUOUS ELEMENT DETECTOR SYSTEMS

the element should be clipped o the structure every 4 inches from end fittings and at approximately 6 inch intervals along its length

• function tests - test circuits are usually arranged to SIMULATE fault conditions by either GROUNDING the centre electrode of the element (resistance type) or introducing additional CAPACITANCE into the circuit (capacitance type). reference should be made to the relevant maintenance manual

Question 16

INSULATION RESISTANCE TESTS - UNIT TYPE DETECTORS

the method of testing differential expansion type detectors consists of measuring the resistance between each _______ and the outer ______, using a ___V _________ resistance tester

Answer 16

INSULATION RESISTANCE TESTS - UNIT TYPE DETECTORS

the method of testing differential expansion type detectors consists of measuring the resistance between each TERMINAL and the outer CASING, using a 250V INSULATION resistance tester

Question 17

INSULATION RESISTANCE TESTS - CONTINUOUS LOOP TYPE DETECTOR

resistance should be measured between the ______ electrode and element ______. the reading obtained should not be less than that specified (a typical value is _ megohm)

an insulation resistance check should not be performed on any single element whose __________ at the time of test exceeds that of the __________ area

Answer 17

INSULATION RESISTANCE TESTS - CONTINUOUS LOOP TYPE DETECTOR

resistance should be measured between the CENTRE electrode and element SHEATH. the reading obtained should not be less than that specified (a typical value is 1 megohm)

an insulation resistance check should not be performed on any single element whose TEMPERATURE at the time of test exceeds that of the SURROUNDING area

Question 18

EXTINGUISHING SYSTEMS

most aircraft use a ‘___ shot’ extinguishing system for power plants. this uses connections between the individual power plant systems. in this system the fire extinguishers for each power plant are ____________. this allows two separate discharges of extinguisher into any one power plant. on many aircraft, two fire bottles are installed in each engine _______. this allows two separate discharges of extinguisher into each power plant. indication that a fire extinguishing circuit has been operated is indicated by a warning _____.

in some installations, special switches are incorporated to automatically operate the extinguishers in the event of a _____. these switches also connect cabin _________ lights to the aircraft battery power supply. two types of crash switch are in common use:

• the ______ control type
• the ________ type

an inertia controlled switch generally consists of a heavy ______ supported on its own spring and so arranged that at the required degree of deceleration (typical value of _G), it compresses the spring and causes a bow spring to snap over thereby ________ contacts connected in the extinguishing circuit. to allow resetting of the switch after operation or rough handling during transit, a _____ plunger is incorporated.

frangible switches consist of two electrical contacts mounted in a hermetically sealed _____ envelope. the contacts are prevented from closing by a spring, but in the event of the glass envelope being _________, the contacts will close and complete the circuit to the extinguishing system. the switches are located in positions such as the wing ____, the underside of engine ________, at various points on the underside of the fuselage, etc. this is so that in the event of a crash, at least one of the switches will be shattered.

Answer 18

EXTINGUISHING SYSTEMS

most aircraft use a ‘TWO shot’ extinguishing system for power plants. this uses connections between the individual power plant systems. in this system the fire extinguishers for each power plant are INTERCONNECTED. this allows two separate discharges of extinguisher into any one power plant. on many aircraft, two fire bottles are installed in each engine NACELLE. this allows two separate discharges of extinguisher into each power plant. indication that a fire extinguishing circuit has been operated is indicated by a warning LIGHT.

in some installations, special switches are incorporated to automatically operate the extinguishers in the event of a CRASH. these switches also connect cabin EMERGENCY lights to the aircraft battery power supply. two types of crash switch are in common use:

• the INERTIA control type
• the FRANGIBLE type

an inertia controlled switch generally consists of a heavy PISTON supported on its own spring and so arranged that at the required degree of deceleration (typical value of _G), it compresses the spring and causes a bow spring to snap over thereby BRIDGING contacts connected in the extinguishing circuit. to allow resetting of the switch after operation or rough handling during transit, a RESET plunger is incorporated.

frangible switches consist of two electrical contacts mounted in a hermetically sealed GLASS envelope. the contacts are prevented from closing by a spring, but in the event of the glass envelope being SHATTERED, the contacts will close and complete the circuit to the extinguishing system. the switches are located in positions such as the wing TIPS, the underside of engine NACELLES, at various points on the underside of the fuselage, etc. this is so that in the event of a crash, at least one of the switches will be shattered.

Question 19

DISCHARGE INDICTORS

many aircraft have a ________ line connecting the bottle to the outside of the aircraft or to an open area such as a wheel well. a ______ disc is located in the operating head and when operated the extinguisher discharges overboard through the discharge line. the discharge line opening is covered with a __________ plastic or metal disc and blows out if there is a discharge exposing the ___ interior of the indicator. discs are generally red in colour but in certain types of indicator, _____ discs are used. discharge indicators are mounted in a structural panel such as a nacelle cowling and in a position which can be seen from the _______ of the aircraft.

a similar system is used to indicate if the system has been discharged by ________ of the extinguishing system. in this case, a small line from the system distribution line leads to a disc-actuator line. this line is covered with a _______ disc. when the extinguishing system is activated, the yellow disc is pushed out by a _______

Answer 19

DISCHARGE INDICTORS

many aircraft have a DISCHARGE line connecting the bottle to the outside of the aircraft or to an open area such as a wheel well. a BURSTER disc is located in the operating head and when operated the extinguisher discharges overboard through the discharge line. the discharge line opening is covered with a DISPOSABLE plastic or metal disc and blows out if there is a discharge exposing the RED interior of the indicator. discs are generally red in colour but in certain types of indicator, GREEN discs are used. discharge indicators are mounted in a structural panel such as a nacelle cowling and in a position which can be seen from the OUTSIDE of the aircraft.

a similar system is used to indicate if the system has been discharged by ACTUATION of the extinguishing system. in this case, a small line from the system distribution line less to a disc-actuator line. this line is covered with a YELLOW disc. when the extiguishing system is activated, the yellow disc is pushed out by a PLUNGER

Question 20

EXTINGUISHERS

each cartridge assembly consists of ___ squibs, electrical connected in ________. a dc voltage of 10-__ volts, at a minimum of _ amps is required to fire each squib. the cartridges are fired by actuation of a switch located ________ to the applicable fire handle

each discharge head has a drain _____ valve installed. the valve is spring loaded open which allows moisture to rain _________ and not accumulate around the initiator cartridge

Answer 20

EXTINGUISHERS

each cartridge assembly consists of TWO squibs, electrical connected in PARALLEL. a dc voltage of 10-29 volts, at a minimum of 3 amps is required to fire each squib. the cartridges are fired by actuation of a switch located ADJACENT to the applicable fire handle

each discharge head has a drain CHECK valve installed. the valve is spring loaded open which allows moisture to drain OVERBOARD and not accumulate around the initiator cartridge

Question 21

DIRECTIONAL FLOW VALVES

directional flow valves are a special type ___-return valve

in some types of aircraft, the cross connecting of selected extinguishers between power plants is achieved by means of ________ switches which are additional to the normal firing switches

Answer 21

DIRECTIONAL FLOW VALVES

directional flow valves are a special type NON-return valve

in some types of aircraft, the cross connecting of selected extinguishers between power plants is achieved by means of TRANSFER switches which are additional to the normal firing switches

Question 22

CARGO COMPT FIRE EXTINGUISHING SYSTEM. SQUIB TEST

the squib test panel provides a means of checking the ________ of the cargo compartment extinguisher bottle discharge squibs.

if there is continuity through the squibs, the _____ lights on the squib test panel illuminate

Answer 22

CARGO COMPT FIRE EXTINGUISHING SYSTEM. SQUIB TEST

the squib test panel provides a means of checking the CONTINUITY of the cargo compartment extinguisher bottle discharge squibs.

if there is continuity through the squibs, the GREEN lights on the squib test panel illuminate

Question 23

CARGO COMPT FIRE EXTINGUISHING SYSTEM. TWO STAGE FIRE EXTINGUISHER

some extinguishing systems are designed to extinguish a cargo compartment fire in ___ stages. first, an initial amount of extinguisher is sprayed into the compartment, then more extinguisher is slowly added to keep the fire suppressed for about __ minutes

the fire extinguisher bottle is designed as a container within a container. the inner container is is connected to the outer container via a ________ orifice. when the fire extinguisher is discharged, the extinguisher in the outer container __________ flows out into the discharge line. the contents of the inner container then slowly leaks out through the metering orifice and passes into the cargo compartment.

the container is filled with _____ and pressured with ________. it is fitted with:

• a ________ valve with an ________ squib
• a pressure switch for ___ pressure indication
• a _______ valve in case of container overpressure

Answer 23

CARGO COMPT FIRE EXTINGUISHING SYSTEM. TWO STAGE FIRE EXTINGUISHER

some extinguishing systems are designed to extinguish a cargo compartment fire in TWO stages. first, an initial amount of extinguisher is sprayed into the compartment, then more extinguisher is slowly added to keep the fire suppressed for about 30 minutes

the fire extinguisher bottle is designed as a container within a container. the inner container is is connected to the outer container via a METERING orifice. when the fire extinguisher is discharged, the extinguisher in the outer container IMMEDIATELY flows out into the discharge line. the contents of the inner container then slowly leaks out through the metering orifice and passes into the cargo compartment.

the container is filled with HALON and pressured with NITROGEN. it is fitted with:

• a DISCHARGE valve with an ELECTRICAL squib
• a pressure switch for LOW pressure indication
• a RELIEF valve in case of container overpressure

Question 24

TYPES OF EXTINGUISHANT.

• BCF (bromochlorodifluoromethane) has little or no ________ effect
• BTM (bromotrifluoromethane) ____ toxic and used for protection of power plant and APU’s. also known as halon ____

in certain circumstances, an extinguishant may ____ the engine and the maintenance manual should be consulted for any checks or precautions that may be required

Answer 24

TYPES OF EXTINGUISHANT.

• BCF (bromochlorodifluoromethane) has little or no CORROSIVE effect
• BTM (bromotrifluoromethane) SEMI toxic and used for protection of power plant and APU’s. also known as halon 1301

in certain circumstances, an extinguishant may HARM the engine and the maintenance manual should be consulted for any checks or precautions that may be required

Question 25

MAINTENANCE. EXTINGUISHERS.

in certain types of extinguishers, removal of the operating or _________ head exposes the main discharge _________. to prevent damage to the diaphragm and injury to personnel, protective _____ must always be fitted to the extinguisher container outlet

before securing cartridge units to extinguishers, they should be inspected for signs of _________, ________, _______ or other damage. the date of manufacture stamped on a unit should be checked to ensure that the cartridge life has not ___________ that specified in the relevant maintenance manual. (the cartridge has a _ year storage life, but only a _ year installation life). checks on the insulation _________, continuity and resistance of the fuse elements should also be carried out

cartridge units often contain __________ and should be handled with extreme care at all times to prevent accidental operation. in some cases, _________ rubber plugs known as ______ are provided, and these must be fitted to the electrical connectors when the appropriate cartridge unit is ________ from its extinguisher, or the system supply cable is disconnected

extinguishers should be handled carefully during installation, and bumping against adjacent parts of the aircraft structure should be avoided. accidental damage of an extinguisher may cause ______ to personnel

Answer 25

MAINTENANCE. EXTINGUISHERS.

in certain types of extinguishers, removal of the operating or DISCHARGE head exposes the main discharge DIAPHRAGM. to prevent damage to the diaphragm and injury to personnel, protective CAPS must always be fitted to the extinguisher container outlet

before securing cartridge units to extinguishers, they should be inspected for signs of CORROSION, DISTORTION, CHAFING or other damage. the date of manufacture stamped on a unit should be checked to ensure that the cartridge life has not EXCEEDED that specified in the relevant maintenance manual. (the cartridge has a 5 year storage life, but only a 2 year installation life). checks on the insulation RESISTANCE, continuity and resistance of the fuse elements should also be carried out

cartridge units often contain GUNPOWDER and should be handled with extreme care at all times to prevent accidental operation. in some cases, CONDUCTIVE rubber plugs known as SHUNTS are provided, and these must be fitted to the electrical connectors when the appropriate cartridge unit is DETACHED from its extinguisher, or the system supply cable is disconnected

extinguishers should be handled carefully during installation, and bumping against adjacent parts of the aircraft structure should be avoided. accidental damage of an extinguisher may cause INJURY to personnel

Question 26

MAINTENANCE. PIPE SYSTEMS

to prevent enlargement or deformation of _____ holes and jets, they should only be _______ by the methods specified in the relevant manuals

Answer 26

MAINTENANCE. PIPE SYSTEMS

to prevent enlargement or deformation of SPRAY holes and jets, they should only be CLEANED by the methods specified in the relevant manuals

Question 27

MAINTENANCE. DISHARGE INDICATORS. WEIGHT AND PRESSURE CHECKS

the fully charged ______ of an extinguisher should be checked at the periods specified in the relevant maintenance _________, and before __________, to verify that no loss of extinguisher has occurred. the weight, including blanking caps and washers, but excluding ________ units, is normally indicated on the container or ________ head.

even if a ________ indicator is fitted in a fire extinguisher system, the extinguisher must be weighed at the specified intervals.

Answer 27

MAINTENANCE. DISHARGE INDICATORS. WEIGHT AND PRESSURE CHECKS

the fully charged WEIGHT of an extinguisher should be checked at the periods specified in the relevant maintenance SCHEDULE, and before INSTALLATION, to verify that no loss of extinguisher has occurred. the weight, including blanking caps and washers, but excluding CARTRIDGE units, is normally indicated on the container or OPERATING head.

even if a DISCHARGE indicator is fitted in a fire extinguisher system, the extinguisher must be weighed at the specified intervals.

Question 28

EXTINGUISHER STORAGE

the _______ of extinguishers should be checked annually during storage, which, in general, is limited to ____ years from the date of manufacture or last overhaul. at the end of this period, extinguishers must be sent for ________.

this storage period period may vary between types of extinguishers, reference must, therefore, always be made to the relevant manuals

cartridge units must be stored in ______ polythene bags in a ________ free atmosphere and kept away from sources of ____. a label quoting the life ______ date, which in general is ____ years from the date of manufacture or last overhaul, should be attached to each bag. if a cartridge unit is removed from its bag, the life expiry date is ___ years from the date of removal, provided the expiry date is within the normal five year period

Answer 28

EXTINGUISHER STORAGE

the WEIGHT of extinguishers should be checked annually during storage, which, in general, is limited to FIVE years from the date of manufacture or last overhaul. at the end of this period, extinguishers must be sent for OVERHAUL.

this storage period period may vary between types of extinguishers, reference must, therefore, always be made to the relevant manuals

cartridge units must be stored in SEALED polythene bags in a MOISTURE free atmosphere and kept away from sources of HEAT. a label quoting the life EXPIRY date, which in general is FIVE years from the date of manufacture or last overhaul, should be attached to each bag. if a cartridge unit is removed from its bag, the life expiry date is TWO years from the date of removal, provided the expiry date is within the normal five year period

Question 29

TREATMENTOF POWER PLANT AFTER EXTINGUISHANT CONTAMINATION

the action taken after discharging a fire extinguisher into an engine (or engine compartment) will depend upon three variables:

• whether the aircraft was in _____ or on the _______
• the type of ___________
• whether the extinguishant entered the ______ or remained _______ the engine

________ extinguishants are extremely corrosive to titanium

on many turbo fan engines, it may be necessary to de-activate the ______ _________ when opening cowlings, or inspecting engines, in order to prevent personal injury

Answer 29

TREATMENTOF POWER PLANT AFTER EXTINGUISHANT CONTAMINATION

the action taken after discharging a fire extinguisher into an engine (or engine compartment) will depend upon three variables:

• whether the aircraft was in FLIGHT or on the GROUND
• the type of EXTINGUISHANT
• whether the extinguishant entered the ENGINE or remained OUTSIDE the engine

HALON extinguishants are extremely corrosive to titanium

on many turbo fan engines, it may be necessary to de-activate the THRUST REVERSER when opening cowlings, or inspecting engines, in order to prevent personal injury

Question 30

PORTABLE FIRE EXTINGUISHERS

CS__ stipulates the requirements for the carriage of hand held (portable) fire extinguishers. the minimum number carried is dependant on _________ capacity

at least ___ hand held fire extinguisher must be conveniently located in the pilot compartment and at least ___ readily accessible hand fire extinguisher must be available for use in each class A or class B cargo or baggage compartment and in each class E or class F baggage compartment that is accessible to ____ members in flight

at least ___ of the required fire extinguishers located in the passenger compartment of an aeroplane with a passenger capacity of at least __ and not more than 60 and at least ___ of the fire extinguishers located in the passenger compartment of an aeroplane with a passenger capacity of 61 or more must contain _____ 1211 or equivalent as the extinguishing agent

Answer 30

PORTABLE FIRE EXTINGUISHERS

CS25 stipulates the requirements for the carriage of hand held (portable) fire extinguishers. the minimum number carried is dependant on PASSENGER capacity

at least ONE hand held fire extinguisher must be conveniently located in the pilot compartment and at least ONE readily accessible hand fire extinguisher must be available for use in each class A or class B cargo or baggage compartment and in each class E or class F baggage compartment that is accessible to CREW members in flight

at least ONE of the required fire extinguishers located in the passenger compartment of an aeroplane with a passenger capacity of at least 31 and not more than 60 and at least TWO of the fire extinguishers located in the passenger compartment of an aeroplane with a passenger capacity of 61 or more must contain HALON 1211 or equivalent as the extinguishing agent