(e)  
The first officer's WARN light is illuminated through an identical logic sequence.

 (3)  
Attitude Comparator Warning (Fig. 3)

 (a)  
Differential resolvers in the captain's and first officer's attitude director indicators are connected to provide common-channel roll and pitch attitude error signals to the input of G6. The attitude error signal is combined with TEST signal from the self-test control. When the error signal is within the prescribed limits there is no output from G6.

 (b)  
The roll and pitch excitation monitor signal is applied to the input of G5. The excitation signal is combined with the TEST signal from the self-test control. When excitation is available and at the proper magnitude, there is no output from G5.

 (c)  
On airplanes without attitude comparator aural warning units,

 EFFECTIVITY
 
 ALL  22 Page 6  Sep 25/9434-44-00

 when a difference (4 degrees when on localizer or 6 degrees otherwise) exists between the two ADI's or the excitation is lost an output is produced at G5 and G6. These signals are delayed to prevent nuisance signals from triggering the logic. The output signals of G5 and G6 are applied to the captain's and first officer's master warn logic and the captain's and first officer's INST WARN light will flash on and off. The output signals of G5 and G6 are also applied to the attitude output drive stage and the captain's and first officer's ATTitude light will come on. Pressing the PUSH TO RESET will manually reset the flip-flop as previously stated; the INST WARN light will go out and the ATT light will dim. When the attitude comparison warning logic failure is corrected, the ATT light will go out. On AF ALL; AT ALL; AZ ALL; GN ALL; MD ALL; SN ALL; VM ALL; IB 406-499; LH 011-099; PLUS ATLAS AIRPLANES INCORPORATING SB 34-2059, when a difference of 4 degrees exists between the two ADI's or the excitation is lost, an output is produced at G5 and G6. As stated above, the captain's and first officer's INST WARN and ATT lights will come on. In addition, the attitude comparator aural warning units will also come on. The aural warning units will operate at a 1.5-Hz per second rate in sync with the INST WARN lights. When the PUSH TO RESET is pressed, the flip-flop will reset as previously stated and the associated INST WARN light and attitude comparator aural warning unit will turn off. The ATT light will also dim. When the attitude comparison warning logic failure is corrected, the ATT light will go out and if it has not been reset, the attitude comparator aural warning unit will go off.
 (4)  
Computer Monitoring

 (a)  The power input (115 volts ac) monitor signal is combined with the TEST signal from the self-test control. When the power input (115 volts ac) monitor signal is at the proper magnitude there is no output at G7. When the power input (115 volts ac) is lost, the output at G7 is logic one. The output signal of G7 is delayed to prevent nuisance signals from triggering the logic. The output signal of G7 is applied to the computer monitor output drive stage to illuminate the captain's and first officer's monitor light (MON). When the computer monitor warning logic failure is corrected the MON light will go out. The INST WARN light does not come on, but pressing the PUSH TO RESET will dim the MON light.

 (5)  
Self-Test

 EFFECTIVITY

 
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 (a)  The TEST signal from self-test control is combined with all logic inputs to the computer. When a remote test switch is pressed, grounding the input to the self-test control, the inverted TEST signal changes to logic one state. This causes a signal failure output at each gate and all the annunciator lights will come on. When the test switch is released, the annunciator lights will go out, except each INST WARN light will continue to flash until it is pressed. On AF ALL; AT ALL; AZ ALL; GN ALL; MD ALL; SN ALL; VM ALL; IB 406-499; LH 011-099; PLUS ATLAS AIRPLANES INCORPORATING SB 34-2059, the attitude comparator aural warning units will come on when the test switch is pressed. The units will go off when the test switch is released.
 B. Controls
 (1)  
Provide electrical power (24-22-00, Manual Control) and ensure that instruments and systems supplying input data to the CIWS are operating.

 (2)  
Check that master radio switches on the P5 pilots' overhead panel and the CIWS circuit breakers on the P7 electronic circuit breaker panel are closed.

 EFFECTIVITY

 
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 CENTRAL INSTRUMENT WARNING SYSTEM - TROUBLE SHOOTING
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本文鏈接地址：747飛機維護手冊AMM CHAPTER 34 - NAVIGATION 第34章導航4(28)