KM-2 Documentation?

[wired521]

Fighting thru a combination of the F10 map heading checks / petrovitch heading checks and lots of trial and error to get from point A to B. Just curious, why don't we have any documentation or content on the correct use of a critical (IMO) change like navigation?

The one video I've found is simply 'how to set' the declination, but nowhere can I find where the values should be. It also seems like, at least on the Persian Gulf map, that the declination isn't static (and requires adjustment during flight).

-42.4 seemed to get me in the ballpark, but after a 60NM flight it was way off (way off being about 20 degrees between indicated heading and what the F10 map or petrovitch show).

Can we please get something (even a forum post) from you ED explaining how this should be used, along with reference values for each map?

[molevitch]

[AeriaGloria]

1 hour ago, wired521 said:

Fighting thru a combination of the F10 map heading checks / petrovitch heading checks and lots of trial and error to get from point A to B. Just curious, why don't we have any documentation or content on the correct use of a critical (IMO) change like navigation?

The one video I've found is simply 'how to set' the declination, but nowhere can I find where the values should be. It also seems like, at least on the Persian Gulf map, that the declination isn't static (and requires adjustment during flight).

-42.4 seemed to get me in the ballpark, but after a 60NM flight it was way off (way off being about 20 degrees between indicated heading and what the F10 map or petrovitch show).

Can we please get something (even a forum post) from you ED explaining how this should be used, along with reference values for each map?

It shouldn’t change with flight. It might change with year. But most maps are pretty static. It should never be on the degree of 42 degrees. 
 

Right now you shouldn’t have to touch anything. Petro will do it all unless you’re in multi crew. HSI/doppler will all show true heading/identical to F10. In multi crew just follow the declinations Molevitch posted and you’ll be in the right ballpark at the least. Or you can always fly the map at the same year in single player and jump in the front seat after Petro sets it.

[wired521]

3 minutes ago, AeriaGloria said:

Right now you shouldn’t have to touch anything. Petro will do it all unless you’re in multi crew. 

Thanks @AeriaGloria - I let Petro set it but ended up waaayy of course (as in, probably 20 NM or more on a 60 NM leg). Moving map thought I was in the right area, but I wasn't. Maybe Petro is hitting the Vodka too hard; lord knows he's all over the place when you let him take the controls.

There's the control in the Pilot-commander station that has the 3-way switch, anything to set there?

I'll try what @molevitch provided (thanks for that).

[AeriaGloria]

13 minutes ago, wired521 said:

Thanks @AeriaGloria - I let Petro set it but ended up waaayy of course (as in, probably 20 NM or more on a 60 NM leg). Moving map thought I was in the right area, but I wasn't. Maybe Petro is hitting the Vodka too hard; lord knows he's all over the place when you let him take the controls.

There's the control in the Pilot-commander station that has the 3-way switch, anything to set there?

I'll try what @molevitch provided (thanks for that).

The Greben with the tune button? AFAIK it should stay in default position. Pressing the tune button fast aligns the HSI. It didn’t do anything detrimental in the past to skip it but maybe you need to do it now.

So you did normal Start up, and are you talking about off course using doppler navigation? 
 

  Becuase if you mean way off course based off of the paper map that can be caused by the doppler limits being +/-7 degrees pitch and +/-30 degrees roll. Above 270 kmh cruise, you basically exceed -7 degrees pitch in constant level flight. When exceeding the doppler limits it goes into memory mode, where it uses last measured ground speed and applies it to your current heading to approximate where you are. So it’s possible to say pitch down to accelerate to 300 kmh, and if you don’t pitch back up above -7 degrees pitch it will just assume your speed is what it was last time you were writing altitude limits. So if I’m level flight, it’s easy for it to measure 260 kmh while you’re actually going 310 kmh. Sometimes I will periodically pitch up at high speed to “update” the ground speed so that what it ls using in memory mode is closer to my current ground speed. 

If you don’t mess with paper map position or power, Doppler navigation and paper map will always agree since they use exactly the same system 

 

Edited April 28, 2022 by AeriaGloria

[wired521]

1 minute ago, AeriaGloria said:

So you did normal Start up, and are you talking about off course using doppler navigation? 
 

 

 

Yes, cold and dark. And yes, the doppler moving map navigation system showed I was roughly in the area I should have been (~60NM from my FARP) however I was about 20 NM away.

For perspective, my heading should have been ~349 and where I ended up was as if I left on a heading of ~315

 

2 minutes ago, AeriaGloria said:

 

  Becuase if you mean way off course based off of the paper map that can be caused by the doppler limits being +/-7 degrees pitch and +/-30 degrees roll. Above 270 kmh cruise, you basically exceed -7 degrees pitch in constant level flight. When exceeding the doppler limits it goes into memory mode, where it uses last measured ground speed and applies it to your current heading to approximate where you are. So it’s possible to say pitch down to accelerate to 300 kmh, and if you don’t pitch back up above -7 degrees pitch it will just assume your speed is what it was last time you were writing altitude limits. So if I’m level flight, it’s easy for it to measure 260 kmh while you’re actually going 310 kmh. Sometimes I will periodically pitch up at high speed to “update” the ground speed so that what it ls using in memory mode is closer to my current ground speed. 

 

 

 

Did any of the doppler navigation features change? I've flown this route multiple times before the patch and never had this issue. My speed was about 250 KPH with a typical altitude of 500-750M AGL. My route of travel was essentially straight and level cruise (no swerving around mountains or maneuvers that would exceed +/- 30 degrees roll).

 

I had the mission on pause and I tried setting the declination to 16 degrees East (shown on the unit as +0160, I assume the last digit is a 10th of a degree). After the change, F10 showed my heading at 268 and the HSI showed ~355 . Will give it another go from a cold & dark start and see if 16 degrees from the beginning makes a difference.

 

 

 

Also, thanks for all the help I appreciate it!

[AeriaGloria]

3 minutes ago, wired521 said:

Yes, cold and dark. And yes, the doppler moving map navigation system showed I was roughly in the area I should have been (~60NM from my FARP) however I was about 20 NM away.

For perspective, my heading should have been ~349 and where I ended up was as if I left on a heading of ~315

 

Did any of the doppler navigation features change? I've flown this route multiple times before the patch and never had this issue. My speed was about 250 KPH with a typical altitude of 500-750M AGL. My route of travel was essentially straight and level cruise (no swerving around mountains or maneuvers that would exceed +/- 30 degrees roll).

 

I had the mission on pause and I tried setting the declination to 16 degrees East (shown on the unit as +0160, I assume the last digit is a 10th of a degree). After the change, F10 showed my heading at 268 and the HSI showed ~355 . Will give it another go from a cold & dark start and see if 16 degrees from the beginning makes a difference.

 

 

 

Also, thanks for all the help I appreciate it!

Just to make sure, you are on open beta on todays update? 
 

have you checked what Petro changes the declination to after start up?

[wired521]

Yes, I'm on openbeta (updated this morning) and oddly enough Petro sets the declination to 2.7E (-0000 0027+ on the KM-2 control head), not 16 (0160) like it should be from what was previously posted. Or, is that 1.6 hard to see . Regardless, F10 map (and petro) show my heading should be 334; my HSI shows about 351.

My farp is at N28 02'30" E55 52' 32" if that helps at all.

I should note, when I say what Petro shows... it's from the AI menu from the pilot-commander seat.

Edited April 29, 2022 by wired521

[wired521]

Ok one more update, I pushed the Sync button from the pilot-commander's station on the control head to the right of the Engine start/ APU panel. (Its a small button under the latitude adjustment labeled PU-38 Greben Match on the tooltip).

After doing this... the HSI slewed to about 339 (only off by 5 degrees now). 

Edited April 29, 2022 by wired521

[sLYFa]

PG magvar is roughly 2°, not 16 (it says 1.6° on the note) 

[wired521]

Thanks @sLYFa I'll give that a shot; assume the correct procedure (after dialing it in) is to press and hold the PU-38 Greben Match button?

[wired521]

Thanks everyone for the help, here's a recap in case anyone else is having issues with the new KM-2 changes:

• Petro's settings did seem to work, even though they were off initially
  • I think this is likely because I needed to press and hold the Greben Match button longer.
• Multiple times during the flight I had to press and hold PU-38 Greben Match (I just bound this to a hotkey) otherwise my HSI would drift
  • Easiest way I found to test the drift from the pilot commander seat is just to bring up the petro menu and see what heading shows up looking straight ahead (F10 map works too)
  • I don't know if this is expected behavior or not
  • Binding the button a key makes life a lot easier, the click spot a little tricky to see unless you're using track IR and don't mind looking down and back a bit.
• I tested this over a 70NM path (went a little further) and didn't have any issues
  • Also used route mode with the autopilot to keep the path as straight as I could, worked fine
  • One thing to note, if you don't catch the drift early this does seem to increase the drift from the moving map doppler system
    • When I first noticed the issue (Before I realized you need to re-sync in-flight) my doppler map was almost spot-on where I SHOULD have been, not where I actually ended up
    • This doesn't really make sense considering how a doppler system would work, but that's what I observed.

Anyway, hope this helps others with the new setup. Maybe Wags will do a deep-dive into this for us  .

Edited April 29, 2022 by wired521

[AeriaGloria]

35 minutes ago, wired521 said:

Thanks everyone for the help, here's a recap in case anyone else is having issues with the new KM-2 changes:

• Petro's settings did seem to work, even though they were off initially
  • I think this is likely because I needed to press and hold the Greben Match button longer.
• Multiple times during the flight I had to press and hold PU-38 Greben Match (I just bound this to a hotkey) otherwise my HSI would drift
  • Easiest way I found to test the drift from the pilot commander seat is just to bring up the petro menu and see what heading shows up looking straight ahead (F10 map works too)
  • I don't know if this is expected behavior or not
  • Binding the button a key makes life a lot easier, the click spot a little tricky to see unless you're using track IR and don't mind looking down and back a bit.
• I tested this over a 70NM path (went a little further) and didn't have any issues
  • Also used route mode with the autopilot to keep the path as straight as I could, worked fine
  • One thing to note, if you don't catch the drift early this does seem to increase the drift from the moving map doppler system
    • When I first noticed the issue (Before I realized you need to re-sync in-flight) my doppler map was almost spot-on where I SHOULD have been, not where I actually ended up
    • This doesn't really make sense considering how a doppler system would work, but that's what I observed.

Anyway, hope this helps others with the new setup. Maybe Wags will do a deep-dive into this for us  .

 

Glad you got it sorted. It makes sense to me it would effect moving map/doppler, as it can’t generate any heading information on its own but relies on the on board magnetic flux compensator/ gyro stabilized heading compass. It can only sense ground speed, drift angle, and vertical speed. It can be surprising how much the doppler has to integrate with in order to form a functional navigational complex. Su-17/20/22, 24, and 25 all also require a doppler system in order to complete the functions of the navigation system and to enhance weapons aiming, as on Mi-24 the doppler also provides wind measurement through ground speed/drift in order to make auto CCIP aiming more accurate 
 

The tune button will slave the HSI at 10 degrees per second. So depending on amount of variation, you may need to hold it longer or shorter. Argentina with a 16 degree declination, will require an Atleast 1.6 second press

Also glad to hear they finally added a button bind for it

Edited April 29, 2022 by AeriaGloria

[wired521]

7 minutes ago, AeriaGloria said:

It makes sense to me it would effect moving map/doppler, as it can’t generate any heading information on its own but relies on the on board magnetic flux compensator/ gyro stabilized heading compass. It can only sense ground speed, drift angle, and vertical speed.

 

That's a great point - makes sense.