INS aligntment at GPU

Hi,

i have a question regarding the INS alignment process. I read the FM, and watched alot of videos but still:

To safe fuel, i do the alignment with engines off and GPU attached. I switch Battery on, get GPU and set the left PSM to "align" (english cockpit) and PCM selector to altitide and check with the altitude at the Kneeboard, then i switch to L/G and type in the give coordinates based again on the Kneeboard. I then hit "VAL", switch to status and wait till its all good and the green "align" (or "PRET" in fra.) LED. Then i usually start the aircraft and turn PSM to "nav", once the engines are running i disconnect GPU and then the yellow "n.align" (or "n.DEG") starts illuminate. Why? Its working fine when i first start the aircraft if i remember correctly.

Are you waiting for the steady or flashing PRET ?

If you stop your alignment when the PRET is flashing your alignment will accumulate more drift overtime and there is a bug that make the N.DEG light go on, but you INS will still work fine.

If you stop your alignment when the PRET is steady you aligment will accumulate the less drift possible and the N.DEG light won't turn on.

A class 4 (shortest) alignment accumulate 4nm drift per hour when a class 1(complete) will drift at 1nm per hour.

i switch to NAV when the PRET is steady. If i do the exactly same process while the engine is already running, everything works just fine.

Maybe bug?

Class 1 alignment take 8 minutes.

Are you sure you wait long enough ?

i switch to NAV when the PRET is steady. If i do the exactly same process while the engine is already running, everything works just fine.

Maybe bug?

Do you rearm after your alignment is complete ? When I say complete I say before PRET is steady.

Class 1 alignment take 8 minutes.

 

Are you sure you wait long enough ?

Yes im am sure. I switch to STS and check Percentage on the right (which is for the Class 1 alignment) and wait for the STEADY PRET LED.

Do you rearm after your alignment is complete ? When I say complete I say before PRET is steady.

Well, i rearm during the process - 8mins is alot. Maybe sometimes even after the alignment is complete. Does that effect the alignment?

Well, i rearm during the process - 8mins is alot. Maybe sometimes even after the alignment is complete. Does that effect the alignment?

Yes, if you rearm after your alignment is complete the INS trigger the N.DEG error. It does not have any impact on your INS AFAIK and you can resolve the error with a ALCM alignment.

You are better to finish your rearm before the end of your alignment.

From memory it's a feature to force the player to do an ALCM when he rearm his plane.

Isn't such a navigation degrade warning on rearm a work of fiction?

Isn't such a navigation degrade warning on rearm a work of fiction?

As much as the idea to rearm the aircraft while aligning its INU, in fact :)

During or after?

okay, at least i know why its illuminating. I will keep that in mind :) thx 4 that.

By the way: When flying in MP, sometimes a class4 alignment is enought - how to stop the process at the current level? just switch it to nav?

okay, at least i know why its illuminating. I will keep that in mind :) thx 4 that.

 

By the way: When flying in MP, sometimes a class4 alignment is enought - how to stop the process at the current level? just switch it to nav?

Yes, you will have the N.DEG it's a bug but it won't change anything.

During or after?

"While" implies "during" AFAIK.

FWIW, "after" would be a no-no IRL too!