Check on Engine Super-Emergency Power Control Syst...
Chapter 3 Special Check
Check on KZW-3 Control Stability Augmentation System(CSAS)
1.Equipment Needed
One ground power unit(GPU)or an equivalent device
2.Preparations
·Open the covering caps of devices close to the CSAS.
·Plug in GPU.
3.Power-off Check
·Check every part of the CSAS in the following aspects:
general condition,deformation,cleanness,reliability and erosion(if any),labels and sealing(of sealed parts).
condition and connection of electrical connectors and the visibility of their labels.
mounting base of each part.
·Check the following accessories:
Circuit breakers:specifications and connections.
Actuator position indicators:electrical connection,needles and scales.
Warning indicators of the CSAS and the coupler:electrical connection and readability.
Coupler indicator:mechanical condition,markings and electrical connection.
Control buttons on cyclic and collective pitch levers:mechanical condition.
Air data calculater:nuts and pipes(general condition,cleanness,erosion and fastening).
Trim actuator:input linkage(general condition,cleanness,erosion,deformation,connection with the control linkage and rocking arms,conditions and cleanness of forks and cotter pins).
Tandem actuator:connection between the shaft and the actuator on the crank,cotter pins,link rod(reliability,cleanness,erosion,general condition and fixation of nuts).
Heading lever switch:mechanical condition and electrical connection.
Conducting wires,line banks,earth link banks,earth points,electrical connectors,sheaths,shielding cases,connection between bulkheads and folor connectors,bonding jumpers and related mechanisms,wires in the sheaths,clamped sheaths and clamps connected to related mechanisms.
General condition,erosion and reliability.
4.Power-on Check
Power on the helicopter and conduct the following check:
·Coupler Console of the CSAS:
Condition of the mechanism,markings,scales and illuminating potentiometers.
Illumination of indicators,markings,scales and if the indicators light up and go out correctly.
·Potentiometer:
Condition of illuminating potentiometers of the instrument panel.
If the potentiometer lights up and goes out correctly.
·Warning indicators of the CSAS:press“TEST”button on 7α panel to check if the warning indicators light up and go out correctly.
Note:Indicator“CSAS”on 7α panel is on when auto-trim switch on the CSAS console is being operated.
5.Finishing Touches
Power off the helicopter and unplug the GPU.
Close the covering caps.
BIT Procedures of KZW-3 Control Stability Augmentation System(CSAS)
1.Equipment Needed
A GPU or an equivalent device.
Note:A ground hydraulic power source or an equivalent device is needed when the CSAS is to work in only one mode for a long time.
2.Preparations
·Plug in the GPU to provide 28V DC power and 115V/400Hz and 26V/400Hz AC power to the helicopter.
·All actuators stay at neutral positions.The gyro horizon and inertial measuring unit of HNS work normally.
3.Test on Lane 1 and Lane 2
·Engage all channels and functions of the CSAS(all switches on the control box face forward);
·Put“TEST”switch at“RUN”position;
·During the whole test(about 30 seconds),the 7-digit display keeps flashing;6 amber indicators(P1,P2,R1,R2,Y,YD)and 3 indicators for automatic trim(“AUTO TRIM”)flash as the test goes on.After the indicators above flash for the second round,the code/digit on the display disappears,calling an end to built-in test.
·If the CSAS passes the test,“0”will be displayed at the end of the test.
·Any malfunction will be indicated by the corresponding code/digit.A maintainer could conduct trouble-shooting based on the digit and the maintenance manual.
·Put“TEST”switch back to“TEST”position.
·Indicators go out.
·Wait until the test ends.
4.Disconnect Lane 1
·Put“TEST”button at“RUN”position;
·During the test on the CSAS working in only one mode,indicators“TRIM”and“COLL LINK”shall light up at least once;
·After the test,put“TEST”button to“TEST”position.The needles of pitch actuator position indicator and roll actuator position indicator would jiggle as before but only with half the amplitude.
Note:The digit displayed is of no value for reference.
5.Disconnect Lane 2 and Reconnect Lane 1
·Disable“COLL LINK”and put“TEST”button at“RUN”position.
·Check the digit(1-7)displayed at the end of the test.
·Put“TEST”switch at“TEST”position and enable“COLL LINK”.
·Reconnect Lane 2.
6.Flight Simulation
·Connect pin D of microswitch 9G with pin E of microswitch 10G.
·Put“TEST”switch to“RUN”position and BIT shall not start.
·Put“TEST”switch to“TEST”position.
7.Finishing Touches
·Remove the short-circuiting wire between 9G and 10G.
·Power off the helicopter and unplug the GPU.
·Decrease hydraulic pressure and then remove the ground hydraulic power source.
Test on AC Power System
1.Equipment Needed
None.
2.Preparations
·Turn on DC power system.
·Turn off inverters 1 and 2.
·Indicators“INV.1”and“INV.2”on 7α panel light up.
3.Testing Procedures
·Turn on inverters 1 and 2.
·Indicators“INV.1”and“INV.2”go out.
·Set voltage selector 10α at positions“INV.1”and“INV.2”to check if the voltage is 115V.
·Put switch“INV.1”at“OFF”position and then at“TRF”(transfer)position.26V and 115V power systems will be restored and supply power.
·Put switch“INV.2”at“OFF”position and then at“TRF”(transfer)position.26V and 115V power systems will be restored and supply power.
4.Finishing Touches
·Turn off inverters 1 and 2.
·Turn off DC power system.
Test on DC Power System
1.Equipment Needed
A 28V ground DC power source and a WQ1 0-40V adjustable voltage stabilizing DC power source.
2.Test on Generators
(1)Preparations.
·Plug in the GPU.
·Start generators.
·Put battery relays 49P(BAT.RLY1)and 50P(BAT.RLY2)at“ON”position,and indicators“BAT.SW1”,“BAT.SW2”,“GEN.1”,“GEN.2”and“BUS.CPL”light up.
(2)Procedure.
·Unplug the GPU.
Note:The GPU can only be unplugged when the rotation speed of the generator reaches the rated value.
·Indicators“BAT.SW1”,“BAT.SW2”and“BUS.CPL”go out.
Generator 1(left):
·Put switch“GEN.1”at“RST”(reset)position and then at“ON”position.Indicator“GEN.1”goes out and indicator“BUS.CPL”lights up.
·Put voltage reading selector 10α at“GEN.1”position and the reading of voltage shall be 28.5V or 27.5V(it depends on the adjustment on the voltage regulator).
Note:If the reading of voltage is not correct,please adjust the voltage regulator.
·Put switch“BAT.RLY1”at“ON”position while switch“BAT.RLY2”remains at“OFF”position.
·Indicators“BAT.SW1”and“BUS.CPL”go out while indicator“BAT.SW2”keeps on.
·After 1s,put switch“BAT.RLY2”at“ON”position.Indicator“BAT.SW2”keeps on while indicator“BUS.CPL”remains off.
·Put switches“BAT.RLY1”and“BAT.RLY2”at“ON”position simultaneously and the corresponding indicators shall go out while indicator“BUS.CPL”lights up.
Generator 2(right):
·Put switch“GEN.1”at“OFF”position and indicator“GEN.1”lights up.
·Put switch“GEN.2”at“RST”position and then at“ON”position.Indicator“GEN.2”goes out and indicator“BUS.CPL”lights up.
·Continue with the test on Generator 2 following the same testing procedures as those for Generator 1.
Test on Shedding System:
·Switch on two generators.
·Check generator voltage with a voltmeter(bus bars PP8 and PP9 are both live).
·Put bus bar shedding switch at“SHED”position and indicator“SHED”on 7α panel lights up.At the same time,power will no longer be supplied to bus bars PP10F(D10-D15)and PP13F(A6-A15)on 4α panel as well as bus bars PP15F(E1-E10)on 5α panel and PP12F(K1-K9)on 2α panel.
Note:Maintainers can also check if the bus bars are really shedded by checking if there is still power supplied to the devices connected to the circuit breakers on the panels.
Engine Shutdown:
·Put switches“BAT.RLY1”and“BAT.RLY2”at“OFF”position and all indicators go out.
·Put bus bar shedding switch at“NORM”position and close the safety cap.
3.Test on Battery and Ground Power Socket System
(1)Preparations.
·Make sure both engines are shut down.
·Put switches“BAT.RLY1”,“BAT.RLY2”,“GEN1”and“GEN2”at“OFF”positions.
·All indicators on 7α panel go out.
·Plug in the GPU.
Note:The GPU plug is always live whether it is plugged in or unplugged.
(2)Procedure.
Test on Ground Power System:
·Put switches“BAT.RLY1”and“BAT.RLY2”at“ON”position.
·Indicators“GEN.1”,“GEN.2”,“BUS.CPL”,“BAT.SW1”and“BAT.SW2”light up.
·Put switch“BAT.RLY1”at“OFF”position while switch“BAT.RLY2”at“ON”position and do it the other way around.
·Indicators“GEN.1”,“GEN.2”,“BUS.CPL”,“BAT.SW1”and“BAT.SW2”keep on.
·Put selector 10α at“EXT”(exterior power)position and check the voltage of GPU on the EPD.
·Put switches“BAT.RLY1”and“BAT.RLY2”at“OFF”position.
·Unplug the GPU.
Test on Battery System:
·Put switches“BAT.RLY1”and“BAT.RLY2”at“ON”position simultaneously.
·Put selector 10α at“BAT”(battery)position and check the voltage of the battery on the EPD.
·Indicators“BAT.SW1”,“BAT.SW2”and“BUS.CPL”are off.
Note:
If switches“BAT.RLY1”and“BAT.RLY1”are not engaged simultaneously,the battery relay switched on later will not be engaged because the shortcircuit protection system will prevent the second battery relay from being engaged as a low voltage has been detected in the corresponding bus bar.Also,the bus bars coupling relay will not be engaged.
During the whole test,battery temperature warning indicator shall not light up.
4.Test on Over-voltage Protection and Reset Circuitry
(1)Over-voltage protection.
·Start engines(it is advised to conduct the test together with the test on engine circuitry).
·As generators work with no load,press the small red button in the center of the radiator of the voltage regulator(28P or 29P)to create an over-voltage circuit.1 second later,the output voltage of the generator rises to about 32.5V.Then the over-voltage protection circuit disconnects the excitation circuits of the voltage regulator and engine.Later the output voltage of the generator drops to below 1V and indicator“GEN.1”(or“GEN.2”)lights up.
·Reset the voltage regulator with switch“GEN.1”or“GEN.2”on 6α panel.And the system voltage will be reset to 28.5V and the generator reverse current protector will be engaged.
(2)Emergency Reset.
·Put switches“BAT.RLY1”and“BAT.RLY2”at“OFF”position.
·Put switches“GEN.1”and“GEN.2”at“OFF”position,then at“ON”position.
·Press“EMERG.RESET”(emergency reset)button.
·The voltage of each generator displayed on an external voltmeter shall increase.
·Put switches“BAT.RLY1”and“BAT.RLY2”at“ON”positions.
·Indicators“GEN.1”,“GEN.2”,“BUS.CPL”,“BAT.SW1”and“BAT.SW2”go out.
5.Test on Ground Power Socket System
·Unplug the battery.
·Connect a 0～40V adjustable DC power source to the binding posts of the helicopter ground power socket.The positive binding posts of the power source are connected to the positive and small binding posts of the ground power socket while the negative binding post of the power source is connected to the negative binding post of the ground power socket.
·Adjust the voltage of the adjustable power source to about DC 28V.
·Put switch“BAT.RLY1”at“ON”position.
·Engage circuit breaker 11P and supply power to the helicopter.An external voltmeter will indicate the voltage of the ground power source.
·Increase the voltage of the adjustable DC power source gradually.
·When the voltage reaches 33±1V,no power will be supplied to the helicopter and the screen of the EPD goes black.
·Adjust the voltage of the adjustable power source back to 28.5V.Still,no power will be supplied to the helicopter.
·Disconnect circuit breaker 11P.
·Reconnect circuit breaker 11P so that power can be resupplied to the helicopter and the EPD will display the voltage of the adjustable power source.
·Disconnect circuit breaker 11P to cut off power from the helicopter and the EPD goes black.
·Put switch“BAT.RLY1”at“OFF”position.
·Set the voltage of the adjustable power source to zero and disconnect it from the ground power socket.
·Reconnect the battery.
Adjustment and Balance Check on Generator Voltage of DC Power System
1.Equipment Needed
One C31-VA DC voltmeter at an accuracy of 1.5
Note:This procedure is conducted when it is the first ground operation adjustment or when a voltage regulator is newly installed.
2.Preparations
·Set the helicopter ready and make sure the battery is installed properly and fully charged.
·Open the cargo bay door.
·Open left and right electric equipment panels.
·Put switches“BAT.RLY1”,“BAT.RLY2”,“GEN1”and“GEN2”at“ON”position.
·Start engines and wait until their rotation speed reaches the rated value.Generators can only be connected with the power network after they enter the rated state(indicators“GEN1”and“GEN2”go out).
Note:When atmospheric temperature reaches or exceeds 35℃,it is advised to set the voltage of the helicopter to 27.5±0.5V.Otherwise,the voltage shall be set at 28.5±0.5V.
3.Testing Procedures(see the figure below)
(1)Voltage Check and Adjustment for No-load Generators.
·Put switches“GEN.1”and“GEN.2”at“OFF”position.Indicators“GEN.1”and“GEN.2”light up.
·Connect the voltmeter with left generator,then with right one:the positive wire is connected to the binding post(3)of the test socket of the corresponding voltage regulator while the negative wire is connected to the fuselage(fastening screw of the voltage regulator(2)).
·Record the voltage of each generator.
·If necessary,adjust the voltage to 28.5V,loosen the locking nut(4)and rotate the adjusting screw(1)to adjust the voltage(28.5±0.5V or 27.5±0.5V as required).Then fasten the locking nut and the voltage shall not change.If not,adjust again.
·Disconnect the voltmeter.
·Put switches“GEN.1”and“GEN.2”at“ON”position.Indicators“GEN.1”and“GEN.2”go out.
·Close left and right electric equipment panels.
·Close cargo bay door.
(2)Balance Check and Adjustment.
Put selector 10α on 6α panel at“GEN.1”position.
·Put switch“BAT.RLY1”at“OFF”position and indicator“BAT.SW1”lights up.
·Switch off Generator 1 and indicator“GEN.1”lights up.
·Check if the voltage of Generator 1 is the same as the adjusted voltage.
·Switch on Generator 1 and indicator“GEN.1”goes out.
·Switch off Generator 2 and indicator“GEN.2”lights up.
·Check the output current value of Generator 1.
·Switch on Generator 2 and indicator“GEN.2”goes out.
·Put switches“BAT.RLY1”and“BAT.RLY2”at“ON”position simultaneously.And indicators“BAT.SW1”and“BAT.SW2”go out.
Put selector 10α at“GEN.2”position.
·Put switch“BAT.RLY2”at“OFF”position and indicator“BAT.SW2”lights up.
·Switch off Generator 2 and indicator“GEN.2”lights up.
·Check if the voltage of Generator 2 displayed on the EPD is the same as the adjusted voltage.
·Switch on Generator 2 and indicator“GEN.2”goes out.
·Switch off Generator 1 and indicator“GEN.1”lights up.
·Check the output voltage of Generator 2.The value shall be the same as that of Generator 1.
·Switch on Generator 1 and indicator“GEN.1”goes out.
·Put switches“BAT.RLY1”and“BAT.RLY2”at“ON”positions simultaneously.And indicators“BAT.SW1”and“BAT.SW2”go out.
·Check the output voltage and current of Generator 2 and set selector 10α at“GEN.1”position.
·Check the output voltage and current of Generator 1.
·Normally,the voltage of Generator 1 shall be the same as that of Generator 2.The output current of each generator is about 40A(25%)and the output current difference shall not exceed 10A.Otherwise,re-adjust the voltage.
·Reduce the voltage of the generator under greater load to reduce its load.
Voltage Regulator
Check on Battery Temperature Detector
1.Equipment Needed
A heating device(electrical oven is recommended),2 containers(0.5L and 1L each),a thermometer(at the accuracy of 0.5℃),an avometer,conducting wires and connecting pins.
2.Preparations
·Remove the battery and put it on the working stand.
·Remove the battery cap.
·Remove the temperature detector(2 nuts and gaskets)from the cells.
·Add water to the container(0.5L)until the water fills 3/4 of its total volume.Then put the container on the oven.
3.Testing Procedures(see the figure below)
·Emerge the temperature detecting assembly in water and make sure the temperature detector(1)does not touch the container.
·Put the thermometer in water and draw the bulb(2)of the thermometer close to the temperature detector.
·Connect the avometer(3)or the continuity tester(4)with the two contactors of the temperature detector’s socket.And the two contactors of the socket shall be connected with the two poles of the switch.
·Heat up the water gradually and keep the water temperature at 60℃ for 10 minutes to make sure the temperature detecting assembly acquires the same temperature as that of water.
·Continue to heat up the water and pay attention to the temperature reading when the temperature detector closes.
·As the temperature detector closes,the needle of the avometer sways from“∞”to“0”or the indicator of the continuity tester lights up.The closing point of a heated-up temperature detector is between 68℃ to 74℃.
·Once the temperature detector closes,remove the oven and put the 0.5L container in the 1L one.Add cold water to the 1L container until the two containers acquire the same water level.
·Note down the temperature(cooling down)when the temperature detector is disconnected.When the temperature detector is disconnected,the needle sways back to“∞”or the indicator of the continuity tester goes out.The disconnecting point(temperature)of a cooling-down temperature detector is 4℃-10℃ lower than the closing point(temperature)of a heated-up temperature detector.
·If the temperature detector is disconnected or closed at a temperature that is not within the limit of tolerance,repeat the procedures above.
4.Finishing Touches
·Take out the temperature detector from water and dry it up.
·Mount the temperature detector(2 nuts and gaskets)onto the cells of the battery.
·Put the battery cap back and install the battery.
Check on Short-circuit Protection Plug-in Unit of DC Power System
1.Equipment Needed
None.
2.Procedure
Note:No device is allowed to be removed when engines are in operation on the ground.
(1)Right Power System.
·Connect both generators with the power network.Indicators“GEN.1”,“GEN.2”and“BUS.CPL”will not light up.
·Disconnect circuit breaker C17 on 4α panel.
·Switch off Generator 2 and indicator“GEN.2”lights up.
·Reconnect circuit breaker C17.
·Put switch“GEN.2”at“RST”position.
·Check if the generator has been connected to the power network.Indicator“GEN.2”goes out.
(2)Left Power System.
·Conduct the same test as that on right power system.In this case,the circuit breaker to be operated is B17 on 4α panel.
Note:If the tests above are successfully completed,short-circuit protection plug-in units 40P and 41P can be seen as working normally.
Check on Diodes of Dual Power Supply Circuitry
1.Equipment Needed
28V DC ground power source.
2.The First Test
(1)Preparations.
·Disconnect the following circuit breakers on 4α panel:A4,A8,B1,B9,B14,B13,B16,B11,B12,A10 and A15.
·Disconnect the following circuit breakers on 5α panel:F1,F2,F3,F4,F5,F6,F7,F8,F9,and F10.
·Disconnect circuit breaker M2 on 2α panel.
·Start engines on the ground.
(2)Check and Trouble-shooting Measures.
·As Nr increases,check the warning sounds from the horn when Nr reaches the maximum and minimum values.If the sounds come back abnormal,change diode 28E on 2α panel or circuit breaker L3.
·Put inverter switches 38X and 39X at“ON”position and check if the 250VA AC power system outputs power and if indicators“INV.1”and“INV.2”go out.If not,check diode 46X and circuit breaker D8 on 4α panel.
·Disengage switch 8F on 12α panel and check the temperature of the pitot tube.Then engage switch 8F to see if the temperature rises.If not,check diode D6 on the 3α panel and circuit breaker D6 on 4α panel.
·Check the display on the fuel gauge 1Q.If there is no display or if the display is not correct,change the fuel gauge.
·Engage fuel transfer switch on 3Q panel and check if the fuel is transferred normally based on the reading on the fuel gauge.If not,check diode D4 on 2α panel and circuit breaker L6.
·Press the test button on 7α panel and check if the landing gear warning indicator“L.GEAR”3G lights up.If not,check diode 56G on 2α panel and circuit breaker L9.
·Put switch 8E at“FIRE”position and check if fire warning indicator 2E(“FIRE”)lights up.If not,check diode D3 on the 3α panel and circuit breaker L4 on 2α panel.
·Check if the CSAS works normally.If not,check circuit breaker D10 on 4α panel.
·Check if the emergency horizon works normally.If not,check circuit breaker G2 on 5α panel.
·Check if the super-emergency power system works normally.If not,check circuit breaker G3 on 5α panel.
·Check if the engine parameter acquisition and display system works normally.If not,check circuit breaker C5 on 4α panel.
·Check if HNS(Hybrid Navigation System)works normally.If not,check circuit breaker H6 on 5α panel.
·Press test button 2D.Check if indicators“CARGO.F”and“O/HEAT”on 7α panel light up.If not,check diode 3W on 32Δ connection box and circuit breaker C9 on 4α panel.
·Check if windshield wipers work normally.If not,check diode D1 on 3α panel and circuit breaker C16 on 4α panel.
·When power is supplied to the helicopter,check if the master warning indicator“ALARM”and most of the indicators on 7α panel light up.If not,check circuit breaker L8 on 2α panel.
·When power is supplied to the helicopter,engage the illumination switch on 12α panel and check if there is illumination in the instrument panel,instruments on the central console,circuit breaker panel,dome control panel and so on.If not,check circuit breaker D15 on 4α panel.
·When power is supplied to the helicopter,indicator“HYD.LEVEL”on 7α panel lights up.If not,check diode D28 and circuit breaker C11 on 4α panel.
·Disconnect the emergency illumination battery.Put the emergency illumination switch and cockpit illumination switch at“ON”position and check if the dome light lights up.If not,check circuit breaker C15 on 4α panel and diodes D1,D2,D3 and D4 on 126L support.
·Shut down engines on the ground and use GPU as the power source.
·Press test button 20G next to the GPU power socket and check if indicator 24G lights up.If not,unplug GPU and engage circuit breaker F8 on 5α panel.Then plug in GPU and press test button 20G.If indicator 24G lights up,replace diode D11 of 19G or 13P on 1α panel.If 24G still doesn’t light up,unplug GPU,disconnect circuit breaker F8 and engage circuit breaker F9 on 5α panel.Then plug in GPU and press 20G.If 24G lights up,change diode D9 on 2α panel or circuit breaker G9 on 5α panel.
(3)Finishing Touches.
·Engage all the circuit breakers that have been disengaged.
·Put all the switches that have been operated in 2.2 back to their previous positions.
·Unplug GPU.
3.The Second Test
(1)Preparations.
·Disengage circuit breaker 13P in main power distribution box 1α.
·Disengage circuit breakers L1,L2,L3,L4,L6,L7,L8 and L9 on circuit breaker panel 2α.
·Disengage circuit breakers C9,C16,C14,D3,D4,D6,D8,D15,C11,C15,C5,and D10 on circuit breaker panel 4α.
·Disengage circuit breakers G9,G3,H6,and G2 on circuit breaker panel 5α.
·Start engines on the ground.
·Check if the CSAS works normally.If not,check circuit breaker A10 on 4α panel.
·Check if the emergency horizon works normally.If not,check circuit breaker A4 on 4α panel.
·Check if the super-emergency power system works normally.If not,check circuit breaker F6 on 5α panel.
·Check if the engine parameter acquisition and display system works normally.If not,check circuit breaker M2 on 2α panel.
·Check if HNS works normally.If not,check circuit breaker E9 on 5α panel.
(2)Check and Trouble-shooting Measures.
·As Nr increases,check the sounds from the horn when Nr reaches the maximum and minimum values.If the sounds come back abnormal,check diode 27E and circuit breaker B13 on 4α panel.
·Put switches 38X and 39X at“ON”position.Check the output voltage of 2×1000VA AC power system on the EPD and check if indicators“INV.1”and“INV.2”go out.If not,check circuit breaker A8 and diode 47X on 4α panel.
·Disengage switch 8F on 12α panel and check the temperature of the pitot tube.Then engage switch 8F and the temperature of the pitot tube shall increase.If not,check diode D9 on 3α panel and circuit breaker B1 on 4α panel.
·Check the display of the fuel gauge.If there is no display or if the display is not correct,replace the fuel gauge.
·Engage the fuel transfer switch on 3Q panel and check if the fuel is transferred normally.If not,check diode D1 on 2α panel and circuit breaker F3 on 5α panel.
·Press the test button on 7α panel and check if the landing gear warning indicator(“L.GEAR”)lights up.If not,check circuit breaker F10 and diode 57G on 5α panel.
·Put switch 8E at“FIRE”position and check if warning indicator 2E(“FIRE”)lights up.If not,check diode D2 on 2α panel and circuit breaker F5 on 5α panel.
·Put switch 9E at“FIRE”position and check if warning indicator 1E(“FIRE”)lights up.If not,check diode D2 on 3α panel and circuit breaker F7 on 5α panel.
·Press the test button 2D and check if indicators“CARGO.F”and“O/HEAT”light up.If not,check diode 2W on 32Δb connection box and circuit breaker B9 on 4α panel.
·Check if windshield wipers work normally.If not,check diode D4 on 3α panel and circuit breaker B16 on 4α panel.
·Check if navigation lights light up normally.If not,check diode D7 on 4Δ connection box on 3α panel and circuit breaker B14 on 4α panel.
·When power is supplied to the helicopter,check if the master warning indicator“ALARM”and most of the indicators on 7α panel light up.If not,check circuit breaker B12 on 4α panel.
·When power is supplied to the helicopter,engage the illumination switch on 12α panel and check if there is illumination in the instrument panel,instruments on the central console,circuit breaker panel and dome control panel light up.If not,check circuit breaker A15 on 4α panel.
·When power is supplied to the helicopter,check if indicator“HYD.LEVEL”on 7α panel lights up.If not,check diode 29D and circuit breaker B11 on 4α panel.
·Connect the emergency battery for illumination.Put switches for emergency illumination and cockpit illumination at“ON”position and check if the dome light lights up.If not,check if the emergency battery for illumination works normally.
·Shut down engines on the ground.
·Press the test button 20G next to GPU power socket and check if indicator 24G lights up.If not,unplug GPU and engage circuit breaker G9 on 5α panel to draw power from the battery.Then plug in GPU and press 20G.If 24G lights up,replace diode D6 on 2α panel or circuit breaker F9 on 5α panel.If 24G still doesn’t light up,unplug GPU,disengage circuit breaker G9 on 5α panel and connect the main power distribution box 13P to draw power from the battery.Then plug in the GPU and press 20G.If 24G lights up,change diode D10 in device 19G or circuit breaker F8 on 5α panel.
(3)Finishing Touches.
·Unplug GPU.
·Engage all the circuit breakers that have been disengaged.
·Put all the switches that have been operated back to their previous positions.
Check on Engine Fire Extinguisher System
1.Equipment Needed
An avometer.
2.Preparations
·Remove rear cowlings.
·Remove the cable plugs of the explosion tubes of two fire extinguishers.
·Remove the protection caps of the fire extinguisher system from the instrument panel.
·Switch on heliborne power system.
3.Check
At least 2 operators are needed in the following check(one in the cockpit and the other conducting the check).
Checking Procedures:
·Press the four buttons of the fire extinguishers in turn.After pressing each button,check voltages of binding posts A and C,B and C,or 1 and 3,2 and 3(markings vary based on the type of cable plugs)of the cable plug of the corresponding explosion tube:
Press the first explosion button of left engine:the cable plug of yellow explosion tube of left fire extinguisher;
Press the second explosion button of left engine:the cable plug of yellow explosion tube of right fire extinguisher;
Press the first explosion button of right engine:the cable plug of gray explosion tube of right fire extinguisher;
Press the second explosion button of right engine:the cable plug of gray explosion tube of left fire extinguisher.
·Check(general conditions,reliability,fastening,cracks,erosion and rust)
cable plugs of explosion tubes
cable plugs of pressure switches
fire extinguishers(check the pressure with a pressure gauge based on the labels on extinguishers)
distribution pipes of fire extinguishers
fire extinguisher nozzles on the rear fire proof wall
Check if there is any crack or fracture on the corners of the mounting bases of fire extinguisher bottles.If any,replace the mounting base(s).
4.Finishing Touches
·Switch off heliborne power system(generators and battery).
·Re-install the protection caps of fire extinguisher system onto the instrument panel.
·Remove the testing unit.
·Connect the cable plugs of the explosion tubes of two fire extinguishers.
·Re-install rear cowlings.
Check on By-pass Valve and Filter Blockage Indicator
1.Equipment Needed
A simulated filter core,a 28V ground DC power source,a fuel container(about 50L)and a fuel drain pipe.
2.Preparations
·Connect the ground power source to the helicopter.
·Open MGB and engine cowlings.
·Remove the locking wire and well place the fuel container.Disconnect the engine fuel-in pipe on the fire-proof baffle plate.
·Connect the fuel drain pipe.
3.Testing Procedures
Note:the test shall be conducted on the fuel-in pipe of each engine in turn.
·Remove the filter core.
·Replace the original filter core with the simulated one and put the simulated filter core into the fuel filter.
·Engage battery relays.
·Switch on booster pumps.
·Check the following points in turn to see:
If filter blockage indicator“FILT”lights up.
If the red ring on filter blockage indicator is fully visible.
Note:If indicator“FILT”doesn’t light up while the red ring on filter blockage indicator is fully visible,press the indication cap and the indicator shall light up.
·Switch off booster pumps.
·Disengage battery relays.
·Remove the simulated filter assembly and re-install the original filter core.
·Reset the filter blockage indicator.
4.Finishing Touches
·Remove the fuel drain pipe.
·Re-install and fasten the fuel-in pipe.
·Remove the fuel container.
·Disconnect ground power source.
·Re-install MGB and engine cowlings.
Check on Low Fuel Level Switch of Feed Tank and Calibration of Fuel Gauge
1.Equipment Needed
A fuel drain pipe,a fuel tank with a fuel gauge with an accuracy within 0.5%,a graduated container(25L)and a fuel container(600L).
2.Preparations
·Lift up and level the helicopter.
·Open right front checking cap(to facilitate operation on the adjusting screw of fuel gauge amplifier)and open MGB and engine cowlings.
·Supply 28V DC power to helicopter.
·Place the fuel container and reduce the fuel in fuel tank groups to 48kg(about 60L).
·Replace the fuel-in pipe on the fire-proof baffle plate with a fuel drain pipe.
3.Testing Procedures(see the figure below)
Note:Low fuel level warning indicator may light up before the booster pumps are switched on but it has to go out after booster pumps enter into work.
·Drain the remaining 60 liters of fuel with heliborne pumps until low fuel level warning indicator lights up.
·Put a terminal of the fuel drain pipe into the graduated container and drain the fuel until the pumps begin no-load operation(dry run).Make sure there is more than 20 liters of fuel in the container.
·Rotate the corresponding adjusting screw on the fuel gauge amplifier to set the display of fuel gauge to 0kg.
·Add 400kg(about 506L)of fuel into the fuel tank groups.
·Rotate the corresponding adjusting screw(2)on the fuel gauge amplifier to set the display of fuel gauge to 400kg.
Note:The display of fuel gauge is supposed to be stable within 2 minutes after each adjustment on the adjusting screw.
·Remove the fuel drain pipes.
4.Finishing Touches
·Lower the helicopter down onto the ground.
·Connect and fasten the fuel-in pipe and remove the fuel container.
·Unplug GPU.
·Re-install MGB and engine cowlings and close the right front checking cap.
Fuel Gauge Amplifier
Check on Transfer Pump and High Fuel Level Switch
1.Equipment Needed
None.
2.Preparations
·Add 150kg of fuel into right fuel tank group.
·Fully fill left tank group with fuel.
·Supply 28V DC power to the helicopter.
3.Testing Procedures
·Check if relative indicators work normally.
·Pull and push the transfer pump switch rightward.
·Check:
If rightward arrow indicator“→”lights up.
If the displayed fuel amount of left fuel tank group decreases.
If the displayed fuel amount of right fuel tank group increases.
Note:Indicator“HI.LEV”lights up when right fuel tank is full with fuel.
·Pull and push the transfer pump switch leftward.
·Check:
If leftward arrow indicator“←”lights up.
If the displayed fuel amount of right fuel tank group decreases.
If the displayed fuel amount of left fuel tank group increases.
Note:Indicator“HI.LEV”lights up when left fuel tank is full with fuel.
·Stop fuel transfer.
4.Finishing Touches
·Disconnect power supply to the helicopter.
Check on Hydraulic System
1.Equipment Needed
None.
2.System Testing Procedures
·Switch on power system:indicators“SERVO”,“HYD1”and“HYD2”light up.
·Press test button for servo and cargo fire“TEST SERVO+CARGO”and indicator“SERVO”goes out.
3.As rotors are rotating
·Indicators“SERVO”,“HYD1”and“HYD2”go out.
·Press the test button on 7α panel.Indicators“SERVO”,“HYD1”and“HYD2”light up.And the master warning light“ALARM”lights up.
·Check if the pressure of left and right hydraulic system is 6.0±0.2MPa(60±2bar).
Press the test button for servo and cargo fire“TEST SERVO+CARGO”.Indicators“SERVO”,“CARGO.F”and“O/HEAT”light up.
4.Test on By-pass Switch
·Press test button 28G on 6α panel and indicator“HYD.AUX”on 7α panel lights up.
·Press the test button and put switch 17G at“BY-PASS”position and indicator“HYD.AUX”goes out.
·Put switch 17G at“NORM”position.
Check on Indicators
1.Equipment Needed
None.
2.Preparations
·Put battery relays“BAT.RY1”and“BAT.RY2”at“OFF”position.
·All indicators on 7α panel,3Q panel and 2G panel go out,so do indicators 17α and 3G.
·Press buttons“TEST”and“DIM”,the indicators remain off.
·Button“DIM”is not live.
3.Testing Procedures
·Put battery relays“BAT.RLY1”and“BAT.RLY2”at“ON”position.
·Most indicators light up.Press buttons“TEST”and“DIM”,and all indicators light up and the master warning light 17α“ALARM”lights up.
·Press indicator 17α“ALARM”and it goes out.
·Press and hold button“TEST”on 7α panel.All indicators on 7α panel,3Q panel and 2G panel shall light up,so do indicators 17α and 3G.
·Press button“DIM”on 7α panel.Indicators on 7α panel,3Q panel and 2G panel dim out while the brightness of indicators 17α and 3G remains the same.
·Release button“DIM”to retrieve daytime illumination.Disconnect 17α indicator and release button“TEST”.
·Put battery relays“BAT.RLY1”and“BAT.RLY2”at“OFF”position and check if all related systems are reset to preparatory status.
Note:To avoid overheat of indicators,the indicator panel shall be dimmed during ground test or flight maintenance.
Check on Microswitches of Shock-absorbing Legs of Main Landing Gear
1.Equipment Needed
An avometer,insulating sealant and insulating varnish.
2.Preparations
·Jack the helicopter.
·Remove the door of landing gear bay(if any).
3.Adjustment on Microswitches
·Check if the shock-absorbing leg is fully extended.
·Loosen and remove 3 bolts(2)from the mounting base(1)to facilitate removal of the cover(4).
·Disconnect the cable plug of the microswitch.
·Connect the avometer to the socket(binding posts A and B).
·Loosen the locking nut(5).
·Rotate the screw(6)to identify the disconnecting points A and C of the microswitch.
·Rotate the screw(6)for 1 or 1.5 round(s)to leave proper clearance.
·Hold the screw(6)and fasten the locking nut(5).
·Drip a drop of varnish on the locking nut.
·Well position the cover(4)on the mounting base(1);fix the cover with 3 bolts(2)and 3 gaskets(3)whose threads have been applied with insulating sealant;lock the bolts and nuts of the microswitch with locking wires.
·Disconnect the avometer from the socket and reconnect the cable plug of the microswitch with the mechanism.
4.Finishing Touches
·Re-install the door of the landing gear bay(if any).
·Lower the helicopter down onto the ground.
Adjustment on the Microswitch
Check on Retraction Interlock between Landing Gears
1.Equipment Needed
A main landing gear restraining panel,an avometer,a hydraulic jack and a 28V ground DC power source.
2.Preparations
a)Supply power to the helicopter.
b)Tilt the instrument panel backward.
c)Connect an avometer between binding post 1A of landing gear control switch 1G and the floor of the helicopter.
3.Testing Procedures
Note:The hydraulic system shall not run with excessive load during the test.Check if the landing gear control switch is secured by safety pins.
a)Install the main landing gear restraining panel on left main landing gear.
b)Jack the helicopter.
c)Check:
·If the shock-absorbing legs of nose landing gear and right main landing gear are extended.
·If nose landing gear is centered and locked.
d)Check if the reading of the avometer is zero.
e)Lower down the helicopter.
f)Remove the main landing gear restraining panel from left main landing gear and install the panel on right main landing gear.
g)Jack the helicopter.
h)Check:
·If the shock-absorbing legs of nose landing gear and left main landing gear are extended.
·If nose landing gear is centered and locked.
i)Check if the reading of the avometer is zero.
j)Lower down the helicopter.
k)Remove the main landing gear restraining panel from right main landing gear.
l)Jack the helicopter.
m)Check if all shock-absorbing legs are extended.
n)Turn the wheels of nose landing gear so that they deviate from the symmetrical center line by more than 2 degrees.
o)Check if the reading of the avometer is zero.
p)Center and lock nose landing gear and put landing gear switch at“EMERG”position.
q)Check if the reading of the avometer is zero.
r)Center and lock nose landing gear and lower the helicopter down on the ground.
s)Make sure rocker arm(2)keeps clear of contactor(1)of the microswitch.
4.Calibrating Procedures
a)If rocker arm(2)touches contactor(1)of the microswitch,re-adjust the microswitch.
b)If the reading of the avometer is not as zero as stipulated in steps 3d),3i)and 3o),re-adjust related microswitches.
c)Conduct the test again after the microswitch(es)is(are)re-adjusted.
d)If the reading of the avometer is still not as zero,replace the microswitch.
e)Conduct the test on newly-replaced microswitch(es).
f)If the reading of the avometer is not as zero as is stipulated in step 3q),replace the emergency switch of the landing gear.
5.Finishing Touches
a)Disconnect and remove the avometer.
b)Lower down and lock the instrument panel.
c)Unplug the GPU.
Microswitch of Landing Gear
Calibration of Compass of Back-up Heading and Attitude System
1.Equipment Needed
A 28V ground DC power source.
2.Preparations
Connect the 28V ground DC power source with the helicopter.
3.Testing Procedures
(1)Requirements.
·Compass calibration is required before the helicopter is delivered from the factory or before the first flight after a large-scale modification on the helicopter.
·Compass calibration is required upon replacement of processor of the back-up heading and attitude system.
·Compass calibration shall be conducted after the back-up heading and attitude system passes the power-on check.
·The compass shall be calibrated on plain sites that are 200 meters away from steel-made mechanisms,underground cables,large metallic pipes,high buildings,high-voltage cables and any physical entities prone to induce changes to geomagnetic field.
·Airborne devices(accompanying devices,products and accessories)shall come with complete supporting devices and shall be properly placed.
·All airborne electrical devices shall be working normally before the calibration.
·Power system shall not be switched off during the calibration,or it will generate great error in magnetic heading.
(2)Check and Calibration.
Preparations:
·Place the helicopter on the calibration site.
·Unlock the control system of the helicopter.Set all movable devices such as control mechanisms,rudder pedals,cyclic pitch levers and collective pitch levers at neutral positions(cruising flight positions).
·Switch on all airborne electrical devices and make sure they work normally.
Compass Calibration:
·Set the calibration switch on the processor of back-up heading and attitude system rightward to“CALI.”position.
·Power on the helicopter and the needle of HSI(horizontal situation indicator)keeps turning clockwise nonstop,indicating that the system is being calibrated.
·When the system is being calibrated,push the helicopter for 2 rounds at a constant speed on the calibration site(720 degrees).Each round shall cost not less than 1 minute.
·Put the calibration switch on the processor of back-up heading and attitude system leftward to“NORM”position.
·Wait until the needle of HSI stops turning(heading is 0 degree),calling an end to the calibration.Then power off the helicopter.
4.Finishing Touches
Switch off all live devices and remove the GPU.
Calibration of HJG-1A Magnetic Heading Sensor of HNS
1.Equipment Needed
None.
2.Requirements
·Compass calibration is required before the helicopter is delivered from the factory or before the first flight after a large-scale modification on the helicopter.
·Compass calibration and zeroing is required upon replacement of the magnetic heading sensor.Zeroing is required upon replacement of the inertial measuring unit.
·The compass shall be calibrated on plain sites that are 200 meters away from steel-made mechanisms,underground cables,large metallic pipes,high buildings,high-voltage cables and any physical entities prone to induce changes to geomagnetic field.
·Airborne devices(accompanying devices,products and accessories)shall come with complete supporting devices and shall be properly placed.
·All airborne electrical devices shall be working normally before the calibration.
3.Preparations
·Place the helicopter on the calibration site.
·Switch on all airborne electrical devices and make sure they work normally.
4.Compass Calibration
(1)Compass Calibration.
·Press selector keys D3,R1 and L1 on MFCD to enter into the navigation page.
·Press“M-CAL”to enter the page for calibration of magnetic heading sensor(as in the figure below).
·Press“M-CAL”to start the calibration and“M-CAL:ON”would be displayed on the display.
·At the same time,push the helicopter for 1 round at a constant speed within 2 minutes.
·In 2 minutes,HNS finishes the calibration and“M-CAL:OFF”is displayed.
Note:The calibration result is classified into 9 levels.If the displayed result is“CAL LEVEL-X/Y:9”,HNS passes the calibration.If not,another calibration is needed.
(2)Warp Correction.
·After compass calibration,align the symmetrical axis of the helicopter with the 0° axis of the calibration site(magnetic heading:true north).
·Read the magnetic heading output by the magnetic heading sensor displayed on the compass calibration page for magnetic heading sensor.
·Calculate the value of warp.
·Press key selector“WARP”and input the warp correction value of magnetic heading sensor with MFK(multi-functional keyboard).For example,if the magnetic heading value of magnetic heading sensor(M-HDG)is 2 degrees,input 2;if M-HDG is 358 degrees,input -2 degrees.
·Press“ENT”to confirm and call an end to the zeroing of magnetic heading sensor.
5.Finishing Touches
·Put switches“INS”,“IDCS”and“HNS”at“OFF”position.
·Switch off all airborne live devices.
·Unplug the GPU.
Compass Calibration Page for Magnetic Sensor of HNS
M-HDG:Magnetic Heading
WARP:Zero Offset Correction Value of Magnetic Sensor
CAL-LEVEL-X/Y:X/Y Axis Correction Level
M-CAL:Magnetic Calibration Enabling
Note:The calibration ends automatically 2 minutes after being enabled.Press“M-CAL”again to stop the ongoing calibration.
Check on Engine Super-Emergency Power Control System
1.Equipment Needed
A 28V ground DC power source.
2.Preparations
·Note down the working time recorded by the engine power detector and recorder and plug in the GPU.
·Put battery relays 49P and 50P at“ON”positions.Indicators“BAT.RLY1”,“BAT.RLY2”,“GEN1”,“GEN2”and“BUS CPL”light up.
3.Testing Procedures
·Engage switch 37E for horn warning and fully turn up the volume of the compass with the knob on the intercom control box.
·Start up one engine according to stipulated procedures and release the start button when Ng reaches 40%.Push the throttling lever to flight position.When torque difference slightly exceeds 25%,two super-emergency power warning indicators light up and the continuous sounds of a gong ring in the headset.Then put the throttling lever back to idling position to decrease torque difference to less than 25%.Two super-emergency power warning indicators go out and the warning sounds in the headset stop.
·Start up the other engine and push the throttling lever to flight position to increase torque difference to over 25%.Two super-emergency power warring indicators light up and continuous sounds of a gong ring in the headset.Then pull back the throttling lever to shut down the engine.
·Disconnect engine super-emergency control switch 121E on 12α panel.Push the throttling lever to flight position again to increase torque difference to over 25%.The super-emergency power warning indicators will not light up and continuous sounds of a gong will not ring up in the headset.
·Pull back the throttling lever to shut down the engine.Open MGB cowlings and check the working time recorded by the engine power detector and recorder.The time recorded shall be the same as the actual working time(timing starts when Ng is over 50%)and the warning flag will not turn.
4.Finishing Touches
·Unplug the GPU.
·Close MGB cowlings.
·Engage engine super-emergency control switch 121E on 12α panel and finish with a lead sealing with a locking wire.
Note:The test shall be conducted when the helicopter is moored on the test stand.