Page 204 Doc # 6.02.01 09 Jan 2003 Rev. 4
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AMM

6. Adjust the Compass System
A. Adjust the magnetic azimuth detector
Do this part of the procedure after the magnetic azimuth detector has been installed for any reason.
Detail Steps/Work Items  Key Items/References 
(1)  Put the airplane on an approved compass swing base. 
(2)  Set the gyro compass system ON. Allow it to complete the start-up sequence. 
(3)  Align the airplane north.  Use an approved external reference compass. 
(4)  Set the slaving control to FREE. 
(5)  Use the CW/CCW switch to zero the slave meter.  Record the algebraic error between the HSI compass card and the actual alignment. 
(6)  Do items 3 to 5 for the other 3 cardinal headings. 
(7)  Add the algebraic errors and divide by 4. This is the 'index error.' 
(8)  Adjust the magnetic azimuth detector: S Loosen the 3 attaching screws of the access panel to which the magnetic azimuth detector is installed. S Turn the access panel with the magnetic azimuth detector by the amount of the index error. S Tighten the attaching screws. 
(9)  Do the procedure again as necessary to minimise the error. 

Doc # 6.02.01 Page 205
Rev. 4 09 Jan 2003

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AMM

B. Adjust the Slaving Control Unit
Do this procedure after the magnetic azimuth transmitter or the slaving control unit has been replaced.
DA 40 Series

Detail Steps/Work Items  Key Items/References 
(1)  Release the the slaving control unit from the left-hand section of the instrument panel: S Release 2 screws. S Pull the unit aft through the instrument panel.  To give access to the screws and the digital meter jack sockets. 
(2)  Put the airplane on an approved compass swing base. 
(3)  Connect a digital millivolt meter to the slaving control unit.  Connect the positive jack to the red jack socket. Connect the common jack to the black jack socket. 
(4)  Set all airplane electrical systems to ON. 
(5)  Set the gyro compass system ON. Allow it to complete the start-up sequence. 
(6)  Align the airplane north.  Use an approved external reference compass. 
(7)  Set the slaving control to FREE. 
(8)  Use the CW/CCW switch to set the HSI compass card to NORTH under the lubberline. 
(9)  Adjust the N/S potentiometer on the slaving control unit to zero the external digital millivolt meter.  Use a non-magnetic blade screwdriver. (0 volts DC ± 50 millivolts). 
(10)  Align the airplane east.  Use an approved external reference compass. 
(11)  Use the CW/CCW switch to set the HSI compass card to EAST under the lubberline. 
(12)  Adjust the E/W potentiometer on the slaving control unit to zero the external digital millivolt meter.  Use a non-magnetic blade screwdriver. (0 volts DC ± 50 millivolts). 

Page 206 Doc # 6.02.01 09 Jan 2003 Rev. 4
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Navigation
AMM

DA 40 Series

Detail Steps/Work Items  Key Items/References 
(13)  Align the airplane south.  Use an approved external reference compass. 
(14)  Use the CW/CCW switch to set the HSI compass card to SOUTH under the lubberline. 
(15)  Adjust the N/S potentiometer on the slaving control unit to zero the external digital millivolt meter.  Use a non-magnetic blade screwdriver. (0 volts DC ± 50 millivolts). 
(16)  Align the airplane west.  Use an approved external reference compass. 
(17)  Use the CW/CCW switch to set the HSI compass card to WEST under the lubberline. 
　
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