GPS question

[HMR]

Thanks Drew. I used to teach classes on the 430 and 530 when each first came on the market. It's been awhile. I'm surprised the lawyers would let them include ILS's in the database even w/the disclaimer.

 

[mike1mc]

ILS approaches are in the Garmin 430. When you load it it gives you a disclaimer that it's for reference only. It won't give you vertical guidance and I don't think it will activate (never tried).

The Garmins do have all the approaches in the database (ILS included), but it is more for reference than navigation. It simply loads all of the fixes for an ILS in the box. The disclaimer says you can't use the GPS for vertical navigation. I think we'd need more info, but maybe he loaded a different approach in the box and was using that to navigate towards the VOR. I can't see any reason why usiing the GPS to navigate towards a VOR would be troublesome on a checkride unless it was part of an approach that he shouldn't have been using. Not sure what kind of checkride yur friend was taking, but could it have something to do with Company Policy or Operations Specifications (if it was for an air carrier)?

 

[ultrarunner]

Thanks Drew. I used to teach classes on the 430 and 530 when each first came on the market. It's been awhile. I'm surprised the lawyers would let them include ILS's in the database even w/the disclaimer.

They are in FMS's. Why not GPS's boxes. LRN is LRN.

 

[bender]

Was the examiner talking about which mode(gps/vloc) the GPS had to be in?

 

[flyinlow67]

Geez, guys. My Garmin 195 handheld has ILS approaches in it! The localizer (runway centerline) is all that shows up, but the fixes are in there.

As to the approach, I would guess the examiner was wanting to see the VOR tuned and ID'd because it was the IAF. You said he thought he had it in the secondary, but if he tuned and ID'd, I'm sure he would remember doing it. Using the GPS is the way most of us do it, but it is always a good idea to have a back up, just in case.

 

[avbug]

Why the confusion here? Quick quiz: what do you call an ILS approach when the glide slope is missing or inoperative?

You call it an ILS.

Don't be surprised then, if the lateral (LNAV) navigation component of an ILS approach is coded in a GPS/FMS/RNAV database. Of course it is. How is this any different than coding a localizer only aproach, a VOR approach, a NDB approach, or a GPS approach? It isn't any different. From the box, they're all installed and flown the same. If you're flying LNAV, there isn't really any difference.

If you have LNAV on board, in whatever form it may be (disregarding any various VNAV capability that a particular unit may have...not applicable here), why would you not load the approach when flying it??

Flying the approach raw data, if you will, and referencing your FMS or GPS unit is only good cockpit resource management and good situational awareness.

Not enough information is given here to determine the purposes of the exmainer, other than the examiner having stated that he didn't want the fixes in the GPS used as the primary navigational item. Rather than speculate on why the examiner chose this path, just use the victor radios, dial in the approach, and fly it normally. Put in the approach in the GPS as backup, state as much, and continue the ride without comment.

While I may not be looking at a moving map or display while on the inbound course of an ILS for primary guidance, I've still got it tuned up on the FMS, and the fixes are right there for quick reference to aid and enhance my situational awareness. The last Business & Commercial Aviation listed an account of an experienced Metro pilot who flew into a hillside and was killed during an instrument approach. It was an approach he had flown hundreds of times. He was flying it raw data. He had an inoperative receiver for one radio, and this deviated from his normal proceedure. He experienced a high rate of descent, flew through the glideslope and impacted terrain. One can only imagine how much better his situational awareness might have been had he a moving map and backup GPS/FMS available to view as he flew the approach. He needn't have used it for primary guidance; he had all the tools necessary to fly the approach safely without it...but what an enhancement, what a gift. Perhaps he would be alive right now.

Lay in the approach. Don't be surprised that it's in the data base, because if you fly an ILS when the glide slope is out, you're still flying an ILS, even if the only operative component is a localizer. It's still called an ILS. The ILS approches coded into the various databases are just the same; they're not providing you with vertical nav information, but they are providing you the same data that you'd need if you flew the localizer only, and it's still an ILS approach, glideslope or not. Because it's designated so.

 

[Checks]

Go to Airnav and look at the approach plates for KMGM. It looks like the FAA has started calling them ILS or LOC. Anybody know why MGM is like this?

 

[Snoopy58]

At least two specific reasons I can think of that having ILS approaches in your GPS/FMS will be helpful:

1. Approach control tells you to maitain some speed or greater until some fix on the approach, or contact tower at (where-ever). While there may be various ways of identifying that fix and perhaps even determining your distance to it, few are easier than having a magic box count down to it!

2. If you go missed approach, having all the fixes and turns available on a moving map is a good "sanity check" that you're flying the procedure correctly. Some places, it's highly recommended to have the approach set up in the FMS (even where you can't fly an FMS approach) specifically so that the missed approach procedure is already active... it's even recommended to, after the inital cleanup during the missed, couple the A/P to the FMS to ensure that the procedure is flown accurately.