What exactly does....

[jrpilot]

...the IRS system do...Nexus made a reference to that and I know I saw it in the PSS FMc but don't know exaclty what it does...it just says "Align IRS"

[Nexus]

It's a self contained navigation system that has been around for many years - long before GPS.

The IRS

[jrpilot]

So is there any payware aircraft out there that have this system for me to try it?

[Nexus]

better yet, there's a freeware INS gauge, a Delco Carousel IV A (CIVA) from simufly.

http://www.simufly.com/ins/

It's a very advanced software that "Correctly Computes/Manages/Displays:

- Current true track angle
- Ground speed
- Along track acceleration
- True heading
- Drift angle
- Inertial Position
- Displayed Position
- Distance between waypoints
- Time between waypoints
- Wind direction
- Wind speed
- Windshear
- Longitudinal wind component
- Action and Malfunction codes"


it's kinda hard to install it, but read the instructions carefully. don't waste you time by installing it on the PSS or PMDG aircraft, bur rather use it in a freeware B742, much more realistic

[zcottovision]

@Nexus:

Thank you for that explanation! I'd always wondered what it was but never bothered asking, and your post explained it perfectly. Thanks!

[Felix/FFDS]

I've been preparing for tax season, so my first reaction was - "Obviously you're not a taxpayer" ....

(For non-US folks:  IRS = Internal Revenue Service; the US government agency charged with the administration of the US Tax Law and collection of revenue taxes.  INS, of course, is the Immigtration and Naturalization Service)