I submitted a ticket to CS Support but it was rejected on the basis that it has already been answered on KB or this forum.  I searched the KB with every search term I could think of, couldn't find it, went through almost every catagory point by point couldn't find it.  I tried search terms "IRS", "IRS Present Position" and some others, no joy.
The problem is this:  after installing 4.3 after I go through all the alignment and NAV procedures and start the flight, the present position on the IRS never changes, neither in VC nor in 2-D modes.  The other functions such as track angle, wind, groundspeed work fine.  I did not have this problem with the original 757 and 4.2

Can anyone direct me to a posting that addresses and resolves this IRS problem?

Thanks in advance.

This is a new one for me.  I'll be doing a flight tonight and I'll check it out and see if I get the same issue.  Anyone else seeing this?

Chris

You will need to check the updated Manual Part II.

The first thing I did after installing 4.3 was to download and read the updated manuals.  I assume Captain Sim 2 is referring to this section of Flight Manual Part II:

Quote

IRS Alignment
An IRS must be aligned before it can enter NAV mode. Rotating the IRS mode selector from OFF to NAV begins the IRS alignment. The IRS performs a short power test, during which the ON DC light illuminates. When the ON DC extinguishes the ALIGN light illuminates. Alignment requires approximately 5 minutes.
Present position (latitude and longitude) must be entered on the CDU position initialization page to complete the alignment. If the present position cannot be entered through CDU, it may be entered through the IRS mode selector keyboard.
If the latitude/longitude position is not near the original airport, the CDU scratchpad message VERIFY POSITION is displayed. If the entered latitude/longitude position does not pass the IRS internal comparison test, the scratchpad message ENTER IRS POSITION is displayed.
Alignment can be accomplished only when the airplane is parked. Alignment stops if an IRU detects motion during alignment. When the motion stops, some units restart the alignment automatically.
The IRS is aligned when all IRUs enter the navigation mode.

Unquote

I understand the first sentence to mean that the IRS mode selector knobs are switched from off directly to NAV, not to ALIGN.  When I do this, the ALIGNMENT indicator lights (3) come on steady, then extinguish, and after about 30 seconds all 3 indicator lights begin to flash.  At this point I open the CDU and input the lat/long for present position in the scratch pad and then enter the data into the boxes using the switch to the left of the boxes.  The ALIGNMENT indicator lights extinguish.  I go through the rest of the preflight settings in the CDU and other panels, taxi and take off.  The Present Position shown on the IRS never changes from the present position entered during preflight and alignment.  I have performed the above procedures with engines running and with engines shut down, the results are the same either way.

Am I misunderstanding any part of the procedures stated in the manual?

Hey there Trailboss

You will be pleased to know that you are not going mad and that you are doing everything right in relation to aligning the IRS.

The thing is you are not alone in your problem and I believe it is safe to say that everyone with the 4.3 patch has this same issue.  From what I have read on the forums nobody can get the IRS GPS positions to change.  I think it must just be a problem with the 4.3 patch.

Hopefully it can be sorted in future updates.  Its not too big an issue anyway as its one of the more minor flight instruments.

Hope this helps

Regards
Neil

You can add me to the list.

Although, honestly, I never noticed until it was mentioned.

Between following the lines and radio navigation, I never even looked.  IRS is still modelled better than many (who don't model it  at all)

Did it work before 4.3?  That's how I was introduced.  

I think the manual is wrong. I move the selectors to align, then after they are ready I put them into Nav at which time the three start to blink. Then I open the CDU to the position page, enter the airport and gate #, then put the gate position into the empty present location field. That stops the nav lights from blinking and all is well. After that I select the flight plan etc. I really like 4.3. Seems to have addressed many of the little problems I had.

Dennis

Dennis

There is in fact this (minor) bug where LAT/LON do not change while flying as it should do.

It really doesn't matter if you set the three knobs direct to NAV, although I think it is more realistic the way you do.

Just for information: on real life, alignment demands 15~20 minutes to be completed...

Regards

Schmid

Thanks for the responses that others have the same problem.  I hope no one misunderstands, I think the CS 757 is a great add-on that has been made even better by 4.3.  However, in Version 4.2 the Lat/Lon did change as the flight progressed because I used it frequently in that mode selection, so there does seem to be something in 4.3 that is causing the problem.  And as several people commented, this is a very small problem given that using Shift+Z I can get continuous present position readout.  

I have to admit I was slightly annoyed when CS Support rejected my official report of the problem.  I fully understand that it's my responsibility to read and understand the manuals, knowledge base data and forum postings before going to them for an answer, but I had done all that, was managing the IRS by the book, and still had the problem.

Well, enough editorializing.  I say again, this is a great add-on (I also have the CS 707, C130, and 727; they are also outstanding, and I would recommend them to any simmer.

Thank you, the issue is on the list for Service Pack. We will do our best to address the issue as soon as possible.

Great, thank CS for the next update !! If you could make a real time IRS alligment that will be fantastique (or to be able to change the time by fast or realistique).