MiG-21 altimeter question...

[BeachAV8R]

Alright - I'm stumped. Show me the error of my ways. I'm at MinVody and getting ready to take off. The tower gives me an altimeter setting of 29.80"Hg. If I put that into an Hg -> mmHG conversion calculator it comes up with 757mmHG. If I roll 757 into my altimeter, it shows 460m instead of what should be 320m field elevation. Both the chart and the F10 map view show my plane as being 321m, so the altimeter is definitely wrong on that setting.

 

 

Does anyone know why this is?

 

:cry:

 

BeachAV8R

[Flagrum]

Just a wild guess ... are you sure you set the altimeter to 757? From the screenshot I would suspect, you set it more to 760 - guessing form the perspective and the angle. Could that be the difference?

[BeachAV8R]

Well, I just went in and took a screen with less parallax and made sure the needle was right on 757 (can someone check my conversion that 29.80" = 757 Hgmm?).. And I show the altimeter off from field elevation by about 265 meters - not an insignificant amount when talking about shooting approaches. Temperature in the mission is 12C, so I wouldn't think there would be a big temperature correction factor. Again, someone check my math and logic here because I can't figure this out...

 

 

 

In the ME the weather is showing 760 - which is close enough to the verbally reported 29.80 by ATC...

 

 

I'm starting to think I should just disregard the altimeter setting called out by ATC and instead just plug in field elevation while I'm holding short.

 

BeachAV8R

Edited November 9, 2014 by BeachAV8R

[BeachAV8R]

OK - so I changed the player aircraft to the A-10C just to see what's going on. I call to takeoff and the controller gives me the same altimeter setting of 29.80. I put that in the Kollsman window of the A-10C and I get 960' = 292 meters which is a fair bit closer to 320 meters expected field elevation than what I get in the MiG-21. So is the MiG-21 altimeter bugged or am I just being dense?

 

 

 

BeachAV8R

[Art-J]

Yep, the Kollsman in MiG seems to be bugged, no matter what airport You're at and whether it's scorching hot or freezing cold, it always shows ~761 mm Hg :D. At least the altimeter hand always shows correct elevation, so You don't have to "plug in field elevation while I'm holding short", because it's already there - that's the good news.

 

The bad news is - there's no way in hell to dial in QFE correctly for landing at other airbase, but tough guys don't need no stinkin' altimeters do we? ;)

 

Edit - these are observations of the last "official" version, I know there have been some adjustments done to altimeter code in open beta, so I guess Kollsman is going to be fixed sometime in the future as well. Cobra, if You're reading this, are You guys aware if this issue?

Edited November 9, 2014 by Art-J

[fjacobsen]

For me it looks more like a setting of 754 than 757.

 

Note that each division is 2.

 

FinnJ

[BeachAV8R]

:) So it's not just me. I mean, you can twist the knob and set the Hgmm in the window, but it seems you are right..it always needs to be set on 760 to properly show the correct elevation.

 

The only reason I noticed it is that I'm putting together some training documents that reference the pattern suggested in the manual, so adherence to altitudes is necessary. Disregarding the altimeter pressure setting solves that problem..as long as 761 gives the proper reading that is good enough until they get it working properly..

 

BeachAV8R

[Focha]

I already reported this some time ago. I don't know if they fix it already on Beta World.

 

So, yes, it is bugged somehow. In Beta they added a conversion chart on the kneeboard, so I guess Its corrected.

 

Also the ATC gives QNH or QNF?

[BeachAV8R]

Yeah, I'm sorry, I just found that thread that discussed this. Apologies for bringing up a known issue.. Looking forward to the corrected one..

 

BeachAV8R