Hi. I did a quick search and couldn't find anything on this.

 

My question is, Do I have to activate the IRS and wait for alignment when moving the aircraft from park to gate? I have experienced a few times that the alignment process never ends. One time I switched from freighter to passenger and just started the engine to move from cargo parking to the passenger terminal. I did not start the IRS for it, but later when ready to start up the alignment never settled. I waited for 25-30 mins before giving up.

 

Thanks

You should not move he aircraft at all until alignment has completed. If you do move, the irs setup will have so many errors it is no wonder it never ends.

 

If you cant wait 10 minutes for the process to complete, simply go to the pmdg menu and select instant alignment. You still need to be stationary, but at least the alignment should take less than a second.

No, you should be able to move the plane, then align the IRSes afterwards without any issues. Starting the alignment, then moving wont work of course.

Also make sure that you've clicked the *INITIALISE IRS button on the INIT page in the FMC! Otherwise it won't work too.

As the others have mentioned, do not move the plane until the initialization is complete. Either move it before, or move it after (in certain aircraft, it will yell at you if it's been moved from the position it was shut down at, but no issues are caused by it).

 

Also, next time it would probably be more appropriate to place an MD-11 related thread in the MD-11 section of the forum. Just a thought...

Thanks for reply guys :)

 

Ok, no need to align for just moving? Details: The aircraft was parked at cargo, I put on batteries and APU (no align process while moving). Started engine 1 and 3 just for taxi to terminal. Parking at the gate, engine shutoff but keep APU running. During this I never touch any of the 3 alignment buttons and FMC. The only units I not turn off is APU and battery.

When starting alignment at the new location it should work, right?

 

Sorry, wrong thread....

Correct, no alignment is needed just to move it, and yes you can align it just fine after the move (with the aircraft remaining still), you just need to input the new coordinates.

And yes, you need to put in the coordinates (via the CDU/FMS) in the appropriate place after you select NAV on the 3 IRS units. Also the engines should be off and of course you need to be stationary. Until that CDU entry is made, the IRS are not alligning, they are just waiting for that entry.

 

Trent Hopkinson

Sure, I never touching any IRS when engine is running or during the movement. Just stationary with engines off. I did not now I have to enter new coordinates after the aircraft been moved. Thanks for all the good response capitanos. :) Very much appreciated.

Sure, I never touching any IRS when engine is running or during the movement. Just stationary with engines off. I did not now I have to enter new coordinates after the aircraft been moved. Thanks for all the good response capitanos. :) Very much appreciated.

 

Well when you align the IRS after moving it you need to enter coordinates like you would usually when starting the IRS, however don't use the last position ones as you since have moved the aircraft, you have to use the new ones from the new location and from memory you will get a CDU prompt stating that they differ from last position (cause the IRS doesn't know you moved, cause it was sleeping :P )

Even if you use the old coordinates the IRS should still align, it would just think that your position is at a different place than what it is

Even if you use the old coordinates the IRS should still align, it would just think that your position is at a different place than what it is

 

I thought the IRS communicate with GPS. If those two don't match it would get wrong. Or something in that alley..