NDB or Compass Locator on ILS

[aviator1x1]

I understand that you can use the Compass Locator or the NDB
as a substitute for the outer marker during the ILS approach. I just want to make sure that if the NDB or the Compass Locator is
out, the ILS approach is not authorized. Is this true?
Part 91 is a little vague. What is the correct answer and please
refer to reg or AIM.
Thank you.

 

[JB74]

Unless radar or dme is being used and specified in the approach.

1-1-9. Instrument Landing System (ILS)

4. Compass locators located at the Outer Marker (OM) or Middle Marker (MM) may be substituted for marker beacons. DME, when specified in the procedure, may be substituted for the OM.

Couldn't find anyting on radar yet....still looking.

 

[Kaman]

Hello,
PAR/ASR can be substituted for the OM or LOM.

regards,

ex-Navy Rotorhead

 

[DAS at 10/250]

Aim Table 1-1-8

GPS with current database can be used in lieu of ADF or DME.

 

[The_Russian]

JB74 said it right. Also, Kaman is correct for ILS approaches in a radar environment. However, GPS can in no way substitute a fix or navaid on a ground based navaid IAP.

Sorry not enough time to elaborate!

Good Luck!

 

[100LL... Again!]

First of all, the NDB/MKR Bcn/DME fix are NOT required EVER to fly the ILS, unless:

DME is in the procedure title e.g.: ILS/DME

or

A procedure note states that the DME or ADF is required.
If it is required, but not in the procedure title, it is because it s necessary to have it to fly the miss.


To repeat, go ahead and fly the ILS with no beacon, no dme, and no adf, unless one ofthe above conditions is stated.

 

[The_Russian]

First of all....

If the NDB/MKR/DME is not present then you have to have radar. So do not go ahead just yet. You have to have a way to join the Final Approach Course in the event of a comms failure. If you dont have radar or comms, you cant shoot an ILS with a GS LOC and ALS only.

 

[100LL... Again!]

You can if the is a NoPT route from a VOR that joins the final approach course.

In the initial issue, I assumed the person was referring to a radar vectored approach.

My point was that GS intercept is the only requirement for flying an ILS in regard to establishing where the FAF is.

 

[The_Russian]

He didnt specify radar. I think we've been cheated! Good point.

 

[JB74]

So what happens in this scenario:


edit: Type in FLL, then scroll down to ILS 27R

http://www.myairplane.com/databases/approach/SouthEast/FLL_ir27R.pdf

Now, in this approach it doesn't specify a DME nor radar requirement, and it doesn't have an OM. Yet the app fixes are identified by DME fixes (as well as VOR int's). My question is (and probably the original posters point also) say you get "radar service lost", are you able to substitute the VKZ R-023 as your FAF in lieu of the dme fix (assuming you don't have DME)?

Hope this makes sense.

 

[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).