IRS is no longer aligned in flight for whatever reason

[skiselkov]

To avoid this:

1. Do not use groundspeed acceleration
2. Do not drag the airplane around using the map after the avionics is powered on

To reset alignment on the IRSes, we need to use a debug menu. Select Challenger 650 > Study > INS > Realign IRUs Immediately and confirm:

Edited January 8, 2022 by skiselkov

[dslbosfgbl]

Thanks, that just saved my a**.

 

is there a non-debug way to do this? There has to be a way to realign the irs in flight right?

[alexcolka]

This post should be pinned.

[OuterMarker]

On 1/8/2022 at 6:38 AM, skiselkov said:

Do not use groundspeed acceleration

Is time acceleration okay or does this cause the same issue?

[Graeme_77]

Time acceleration should be fine.  Ground speed acceleration is not compatible with the IRS simulation though.

[Lightcivvie]

On 1/10/2022 at 5:00 PM, dslbosfgbl said:

Thanks, that just saved my a**.

 

is there a non-debug way to do this? There has to be a way to realign the irs in flight right?

Non-debug way: If you have a red 'HDG' flag, go to the FMS, 'IRS CONTROL' page, select the offending IRS, and at the bottom right, enter the current heading obtained from the magnetic compass. This is also aircraft procedure, although there is more to it. 

I got the red HDG after using time acceleration, did not know about the sim option to realign in flight.