Hi Folks.I am still trying to get to grips with this complex sim. I am reading through various tutorials with not a lot of success really. One thing that I would like explained if possible, is why the IRS system ' resets ' itself back to a time of 7+ mins.Here's what happens and I accept that it may well be that I am not doing things quickly enough when working through the Pre Start Checklist and tutorials.I power up the cockpit, set the IRS system in motion and work through the rest of the checks. The IRS countdown on the ND gets to 0 then goes back to a figure of 7+ with no update of position, heading or flight plan legs showing on the ND screen.Am I doing something wrong? Oh, also, one of the tutorials has a cold and dark sav file loadup at startup. When I select the battery to ON I immediately get a warning chatter and the screens stay dark until I start the APU. The tutorial says I should hear a cockpit fan and the screens should come alive allowing me to monitor APU engine signs. Again, I am doing something out of sequence which is causing the chatter.Regards...Ken

You need to enter the IRS position via the FMC.

double post

( Once Battery power and apu power established) I simply just move the IRU selectors to the nav postion then wait as it aligns, ussualy I will go through some sytem checks. once at zero I use the FMC to intialize.Paul ( Toronto Canada ).

You need to initialize it before it gets to zero. That's what's causing the trouble.

You need to initialize it before it gets to zero. That's what's causing the trouble.

Yeah but that's not realistic :( You can theoretically leave an IRU in align for 20 hours and only then enter the position - it should then switch to NAV mode.

Hi Guys.Thanks for all the input, I appreciate it. It looks like I have not given enough info re. the IRS. The tutorial I am using is Smitty Smiths Standard Procedures Guide. This instructs me to enter the IRS position into the FMC straight after setting the switches to ALIGN. This is prior to starting the APU. I'll keep trying the Tutorial until I get it right.Any clues as to the cause of the warning chatter?Regards...Ken

Hi!I am with you, but have also the problem that the indicated airspeed in the PFD is blank and not active. Do you have solutions ?Phil