NDB or Compass Locator on ILS

[The_Russian]

Check the top left corner of the ILS 27R at FLL. It's a ILS/DME.

 

[DAS at 10/250]

The Russian: My understanding is that a GPS w/ current database is an acceptable substitution for ADF or DME. So, if your ACFT was say GPS equipped (ex. Garmin 400/500) and tuning in the LOC your could identify the FAF or step down fixes with the GPS. One example I am refering to is the Austin, TX ILS 17L (KAUS). My thoughts are that an approved GPS could also substitute the DME for an ILS DME. I know the argument will be made that this appch requires RADAR, but you will still need a way to identify DOFFS, SCALI, and GAPPI(FAF), which are charted as DME fixes on the LOC.

Thoughts?

 

[JB74]

I understood the LOC/DME next to the identifier and channel to mean it simply broadcasts distance info, not an approach requirement. I always thought that if it was required, it was to be either in the title or in the remarks sections. Hmmm, learn something new everyday. Thanks.

 

[DAS at 10/250]

Attachment to above post:

Also assuming your #2 VOR is INOP or not installed.

 

[The_Russian]

When I go to the Academy tomorrow I'll check in my AIM and get back to you on that ASAP. I know that the AIM doesn't associate GPS with ground based navigation even though manufacturers have found ways to allow the GPS to shoot all types of approaches.

 

[DAS at 10/250]

I think I found the answer authorizing GPS for use on an ILS

AIM 1-1-20

5.

(c). Navigating to/from and NDB/compass locator.

(d). Determining the aircraft position over an NDB/compass locator.

(e). Determining the aircraft postion over a fix defined by an NDB/compass locator bearing crossing a VOR/LOC course.

(f). Holding over an NDB/compass locator.

 

[100LL... Again!]

Let's make sure we're clear:

If it is an ILS/DME as stated in the TITLE of the procedure,
Ex: ILS/DME 32 , the DME is required, or GPS as a substitute.


If the LOC simply has DME AVAILABLE, it is not necesarily required.
Again, see procedure title.

 

[JB74]

100LL......Thats what I thought.

The title simply states ILS 27R, where the LOC/DME ident box is what I think The_Russian was refering to.

So it appears that the FLL ILS 27R, which dosn't have an OM, requires neither DME nor RADAR. So, what determines the FAF when not in RADAR contact or when not equipped with DME?

Man, I am really confusing myself now

 

[Mmmmmm Burritos]

Good grief guys

The FAF on an ILS doesnt have anything to do with OM/CL/NDB/DME/RADAR or anything. It is simply when you intercept the glideslope while on the localizer.

Now, if you are doing a LOCALIZER ONLY approach, (either you dont have a glideslope receiver or the glideslope is busted) you will need to identify a FAF so you can start your descent and your time, or have a DME to identify the MAP. The MAP on an ILS is the DA.

On the FLL ILS 27L, you do NOT need a DME to shoot this approach. It merely starts LOC/DME because it's there ready for you to use. It would either say ILS/DME 27L or say DME REQUIRED in the notes. You can identify the FAF for the LOCALIZER approach (if no glideslope) three ways, either by DME, the VKZ 023 VOR radial, or ask the controller to identify it for you (RADAR). If not, then you'll have to switch your NAV 1 quickly to the VOR and see where you are in relation to it, then switch back. It's not all that hard, and I've heard of people having to do this on an ATP checkride.

And yes you can use GPS in lieu of NDB and DME. IT states that a few times in the AIM. I have shot NDB approaches before without ever tuning in an NDB. You can do this even if the NDB is broken. All you need is an IFR GPS and the know-how. The GPS basically turns the NDB into a VOR and you shoot the approach with VOR-style course guidance (CDI not ADF). It's easy!

Oh by the way, my avatar picture happened to me when I was shooting the ILS 17L into Austin (mentioned above). Luckily it was VFR and we were able to land at Bird's Nest airport. Talk about podunk airports!!

 

[de727ups]

FAF on an ILS

Is the PUBLISHED glide slope intercept altitude (GSIA).