Magnetic Compass Synchronization problem - ED Forums
 


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Old 12-02-2019, 11:16 PM   #1
highwymn
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Default Magnetic Compass Synchronization problem

On the front dash (Top Right) There is a red lamp and push button) that is supposed to synchronize the Magnetic Compass. (pg 115 in the DCS L-39 manual as number 23 & 24)

In doing the training missions and a little interesting flying for fun, I found the Radio Magnetic Indicator (RMI) was off. Supposedly, unless I am misunderstanding, this button is supposed to realign (realigned while in straight, level, accelerated flight). It does not.

On the PU-26E, I supposedly have the correct settings, being Magnectic Compass (MC), N (as opposed to S, for the Caucus Map), and 43.5 degrees Lattitude.

Is this a bug, is it not working correctly currently, or am I just not doing this correctly? Or is that button just to extinguish the light? I have had the compass off by at least 5-10 degrees and the light never lights up... Am I supposed to Change or synchronize it on the PU-26E using the "HDG Select"???

Maybe the PU-26E has to be in the Gyro Compass (GS) mode, or what am I missing exactly?


Last edited by highwymn; 12-02-2019 at 11:33 PM.
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Old 12-03-2019, 01:12 PM   #2
Ramsay
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Are you allowing for the fact that the RMI uses True headings (rather than magnetic) i.e. it uses the Gyro correcting mechanism in the rear cockpit to adjust for magnetic variation.

At Batumi RWY 31 the RMI will show 306°T, while the KI-13 Magnetic Compass will read 300°M.

Magnetic variation on the DCS Caucasus map is approx 6-7°E depending on location and date i.e. you need to add +6° to a magnetic compass to get the True bearing.

Quote:
Originally Posted by highwymn View Post
On the PU-26E, I supposedly have the correct settings, being Magnectic Compass (MC), N (as opposed to S, for the Caucus Map), and 43.5 degrees Lattitude.
In MC mode, gyro drift is corrected using signals from an inductive transmitter that feed through the correcting mechanism to the gyro, i.e. so it is aligned with True North.



AFAIK the large needle on the correction dial should give the magnetic heading as detected by the transmitter, in DCS it's a repeat of the RMI (true) bearing.

Declination adjustment for the real device is +/- 18.0°, in DCS it uses the same scaling factor as the compass i.e. +/- 180°


Last edited by Ramsay; 12-03-2019 at 03:06 PM. Reason: Add GMK Gyro Correcting Mechanism diagram
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Old 12-04-2019, 01:53 PM   #3
JG14_Smil
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Great post Ramsay!
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