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jumboross

744 IRS

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Hello all.I'm working my way through the 744 Type Rating Course and it's all going quite well (with some assistance from the forum members!) so far. The problem I'm having is getting the IRS to align from a cold start. I thought I was doing it correctly and the 'time to align' counted down from 7 minutes to 1, but then went up to 26 and even more? I've adjusted the setting to 'instant' on the options page but still no joy.I've read the Normal Procedures in conjunctions with the Type Rating Course notes and the procedure as I understand it (it was revised in the TRC notes) is for all three switches to be moved from 'OFF' straight to 'NAV' but this doesn't seem to work. If I ignore the TRC notes and move the sitched from 'OFF' to 'NAV' then 'ALIGN' (as per the Normal Procedures doc) I get the same thing where it starts at 7 minutes, counts down then goes back to a much bigger amount of time?Can anybody here help me with the correct procedure? Also will the PFD update to include the display where you get blue sky and orange ground when the IRS aligns? The display when I start up doesn't have a horizon in and is quite difficult to use!Thanks is advance for any help.James Ross.

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Hello all.I'm working my way through the 744 Type Rating Course and it's all going quite well (with some assistance from the forum members!) so far. The problem I'm having is getting the IRS to align from a cold start. I thought I was doing it correctly and the 'time to align' counted down from 7 minutes to 1, but then went up to 26 and even more? I've adjusted the setting to 'instant' on the options page but still no joy.I've read the Normal Procedures in conjunctions with the Type Rating Course notes and the procedure as I understand it (it was revised in the TRC notes) is for all three switches to be moved from 'OFF' straight to 'NAV' but this doesn't seem to work. If I ignore the TRC notes and move the sitched from 'OFF' to 'NAV' then 'ALIGN' (as per the Normal Procedures doc) I get the same thing where it starts at 7 minutes, counts down then goes back to a much bigger amount of time?Can anybody here help me with the correct procedure? Also will the PFD update to include the display where you get blue sky and orange ground when the IRS aligns? The display when I start up doesn't have a horizon in and is quite difficult to use!Thanks is advance for any help.James Ross.
From OFF, to NAV and then to ALIGN. Lastly, counter on 0 min = switch it back to NAV. This is according to the PMDG manual, read it... as it's very useful and handy. I hope you get it sorted out now... cheers!Oh, and yes.. the PFD and NAV display will startup nicely after IRS pos int. is completed.EDIT: You did set the coordinates in the FMS, the IRS need those numbers in order to align?

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SamiI hadn't put the coordinates into the FMC, that was the problem. All sorted now. Thanks for your help.James.

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SamiI hadn't put the coordinates into the FMC, that was the problem. All sorted now. Thanks for your help.James.
No probs, at least now you can enjoy your PMDG 747! :)

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SamiI hadn't put the coordinates into the FMC, that was the problem. All sorted now. Thanks for your help.James.
There is no need to put in the coordinates... Its a gps based system... the IRUs are not really even needed. But in the pmdg plane you have to put them in... So what I do when the countdown goes from 7 to 1 and such I put in the gps position once and then I put it in again when it says it needs the position... So I put it in again and I am ready to go.

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There is no need to put in the coordinates... Its a gps based system... the IRUs are not really even needed. But in the pmdg plane you have to put them in... So what I do when the countdown goes from 7 to 1 and such I put in the gps position once and then I put it in again when it says it needs the position... So I put it in again and I am ready to go.
Correct me if I'm wrong (new here), but isn't the IRUs required for CAT III and II Autoland/ILS (saw it in the PMDG manual). The manual also states that the system (IRS) provide information regarding acceleration, attitude, ground speed, track, true and magnetic heading, wind direction and speed. Also, it backs up the GPS system along with VOR/DME correction so that the FMS can calculate the correct longitude, latitude information (GPS, VOR/DME and IRUs working together in order to give the FMS the most accurate information possible).Anyway, it'll really help me if you can explain to me why the IRUs aren't needed? I have placed an order on the PMDG747 (should arrive in a week) and I'm trying to learn like a mad man about the PMDG747. Thanks! :)

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