BIT Procedures of KZW-3 Control Stability Augmenta...

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.