ADIRS Operations ( Alignment )

[Neupielot]

Fcom 3.4.34-ADIRS
Avoid alignment during an engine start, or while the engines are running.

Need a bit of help here plz.

If the aircraft is stationary ( not blocking any traffic eg. still at the remote stand ) and the engines started. Any potential problem with re-alignment ?

I know, u must be thinking , why realign after u start? Cos sometimes the computers do crazy things and I'm thinking a IRS realignment might help. But after reading the Fcom- i'm not sure if we can do that......

Many thanks.

[LME (GOD)]

If ATC will let you block a taxiway for 10 minutes then fill your boots!! Probably not recommended due to the slight movement you get with the engines running.

[Neupielot]

Thanks.

But as for If ATC will let you block a taxiway for 10 minutes then fill your boots

I know its highly unlikely but like i saideg. still at the remote stand

Some airfields have Remote parking that doesn't need push back eg. ZSPD ( shanghai ). So u won't be blocking anyone at all actually.

But thanks once again. :ok:

[Bullethead]

I don't think the motion you get from having engines running is any worse than you get from sitting in strong gusty conditions or having passengers boarding and performing an alignment with engines off.

I have aligned IRSs countless times in gusty conditions witout any problem.

Regards,
BH.

[Slasher]

Isnt an ADIRU input needed by the BMC to compute relative pressure like whats needed for engine start?