Compass HDG slave knob

In the pilot cockpit, on the right console, there's a knob next to the ILS, with the label: Compass HDG slave knob? Do you know what is its use?

If you have the Compass reverted to the DG setting (not using INS or Magnetometer for heading reference) you use that knob to adjust the heading indication manually to match the magnetic compass up on the glare shield.

Also when you leave the carrier and are out of its magnetic anomaly zone you push the button part of the knob to re-align the magnetometer so it can read properly. (it will also eventually do this itself slowly)

Thanks Rust for the informative reply.

How can I revert the compass to the DG setting?

Turn the middle knob on that panel right to DG.

At least I assume, never had to touch it.

I think I incorrectly assumed DG settng is when the aircract compass matches the standy compass . Can you please enlighten me?

What is the DG setting? When it comes to the standby compass, it seems to never be affected by the magnetic field of the CV but it also never shows the same heading at the BDHI. Is there a reason for all these discrepancies?

DG is the directional gyro mode, which means that the gyroscope providing heading for the AHRS is disconnected from the magnetic field sensor (which is a seperate device and has nothing to do with the standby compass). This means that the AHRS heading gyro will not be recieving any updates to where magnetic north is but can instead be adjusted manually with the course knob. There are a few more implications to using that mode but given the small size of the DCS maps they are irrelevant.

The BDHI should show the same heading as the standby compass in the SLAVED mode when on the boat, however I never really paid attention to whether the standby compass is also affected by the carrier but I would think it should.

The heading indicator in many modern aircraft is a gyroscope connected to remote magnetic sensor located outside the cockpit. The magnetic sensor aligns the gyro to the north, while the gyro itself tracks aircraft heading in turns and during acceleration, something that simple whiskey compass cannot do.

In DG setting, you disconnect the magnetic sensor and can then align the gyro manually with HDG knob. It won't realign itself to the north any more (that's your responsibility from now on), but it will still track your heading changes. And it will be susceptible to gyro drift over time.

At least that's how it works in real aircraft, it's a backup mode of operation, not very relevant in DCS world.

I actually had to use it today following a very energetic SAM evasion that borked the heck out of the INS.

If you borked the INS, then I think you could still revert to compass mode, no need to go full retard to DG. :)

Compass mode will turn the BDHI into an oversized whiskey compass, not very useful unless you fly straight and level. Still better than trying to make out the heading on the standby compass but if the gyros still work, DG with the correct heading set is the far better option.

Ah, yes, that's what COMP position does in F-14 specifically. So that's the "full retrard" position. :)

But in case of INS failure, you shouldn't need that switch, AHRS can still work in SLAVED mode.

Right, if the gyro is still working you can also used SLAVED, didn't think of that :D

I think DG could be useful when you land on the carrier to avoid the AHRS being thrown off by the carrier's magnetic field distortion.

Don’t tell me, tell the wheel of fortune wheel my compass rose became.