Localizer approach question: timed or DME required?

[Jim Logajan]

I'm unclear whether the localizer approach on this plate can be flown by timing from the BRULE intersection to the MAP or whether it requires a DME per the note in the profile box. If DME, what purpose does the FAF to MAP timing box serve? (For my purposes it would be nice if it could be flown with just a VOR, localizer, and a clock.)

https://skyvector.com/files/tpp/2301/pdf/00324IL31.PDF

 

[tawood]

It looks to me that they are saying the localizer requires DME...maybe the timing is for backup if the dme quits mid-approach..>?

 

[Jim Logajan]

It looks to me that they are saying the localizer requires DME...maybe the timing is for backup if the dme quits mid-approach..>?

That would seem to be the case, though I'm having a hard time finding confirmation anywhere.

The LOC/DME notation is supposed to mean DME required. On the other hand you only need a VOR and localizer to triangulate the FAF and timing at estimated ground speed along the localizer course to know when you've reached the MAP. Though you will arrive over the VDP earlier than the MAP. All rather odd.

 

[Jim Logajan]

The reason I ask about that approach plate is that the club's airplane will be able to fly ILS, localizer, and VOR approaches, but doesn't have a DME, GPS, or an ADF. The ACS now states that to pass the instrument rating practical exam requires one precision approach and two non-precision approaches (the latter two must use two different navigation systems.)

(1) An ILS approach at KRAP (Rapid City) can satisfy the precision approach with that equipment. Requires radar vectors to the FAF.
(2) KRAP also has a VOR approach where passage over the VOR marks the FAF and requires timing to the MAP. No requirement for DME, etc. So one non-precision.
(3) Alas, the KRAP localizer approach coincident with the ILS approach does not have a FAF to MAP timing table. The above ILS/localizer approach plate is the only one I've managed to find within 150 nm that has a localizer FAF marked by a VOR radial/localizer intersection and a timed approach to the MAP. Thus making it potentially a second non-precision approach. The DME requirement on the localizer approach seems odd since technically not needed.

Wondering what latitude is allowed to an examiner on an IR checkride with respect to approaches when the plane can do them but no airfields that require the three required are not in realistic range. (Having a DME installed would be the cheapest way to bypass the issue. But it's a leased plane, so....)

 

[PeterNSteinmetz]

This is odd. AIM 5-4-5 a.3.(a)-(c) talks about the appropriate annotations regarding equipment required. But none of those mention an annotation like in this chart where the DME is mentioned in the descent profile.

This is not the first time I have seen errors in IAP charts, so this may just be another one.

You could submit a query about this approach to the FAA aeronautical information services. https://www.faa.gov/air_traffic/flight_info/aeronav/ . They might decide to clarify the chart.

It strikes me you could fly this as non-precision. But if you are getting close, maybe find the DPE you will be using and ask him what he does.

 

[PeterNSteinmetz]

The LOC/DME notation is supposed to mean DME required.

I believe that is a requirement if the / notation is in the title. (See previously cited AIM sections). But in this case it appears in the frequency box which I believe means that is the frequency for the LOC and the DME, but does not specify a requirement.

 

[Jim Logajan]

I believe that is a requirement if the / notation is in the title. (See previously cited AIM sections). But in this case it appears in the frequency box which I believe means that is the frequency for the LOC and the DME, but does not specify a requirement.

You're right.

It just occurred to me that there are two DMEs on the plate (at the ILS and the VORTAC) and the notation may just be advising that the DME distance to use, if you are using DME to determine the FAF or MAP, is from the ILS not the VORTAC. Such an advisory makes sense if you first fly one of the DME arcs which are centered on the VORTAC. Then once turned on to the localizer course and you want to use DME to locate the FAF you have to switch to using the localizer DME. Using the VORTAC DME at that point would be mess with your head.

Side observation is that VOR appears required since without it you can't navigate to ANY of the IAFs or the missed approach hold point over the VORTAC. Or know when to start turning inbound on the DME arcs.

Anyway, at this point I'm pretty sure DME is not required and the note is advisory since no where is the magic word "required" nor is DME in the title. I'll wait a while before asking clarification from the FAA.

 

[PeterNSteinmetz]

It just occurred to me that there are two DMEs on the plate (at the ILS and the VORTAC) and the notation may just be advising that the DME distance to use, if you are using DME to determine the FAF or MAP, is from the ILS not the VORTAC.

Good catch! Amazing the amount of detail in these plates.

This has been good training for me since I am working on my CFII for this year’s flying project.

 

[tawood]

The reason I ask about that approach plate is that the club's airplane will be able to fly ILS, localizer, and VOR approaches, but doesn't have a DME, GPS, or an ADF. The ACS now states that to pass the instrument rating practical exam requires one precision approach and two non-precision approaches (the latter two must use two different navigation systems.)

(1) An ILS approach at KRAP (Rapid City) can satisfy the precision approach with that equipment. Requires radar vectors to the FAF.
(2) KRAP also has a VOR approach where passage over the VOR marks the FAF and requires timing to the MAP. No requirement for DME, etc. So one non-precision.
(3) Alas, the KRAP localizer approach coincident with the ILS approach does not have a FAF to MAP timing table. The above ILS/localizer approach plate is the only one I've managed to find within 150 nm that has a localizer FAF marked by a VOR radial/localizer intersection and a timed approach to the MAP. Thus making it potentially a second non-precision approach. The DME requirement on the localizer approach seems odd since technically not needed.

Wondering what latitude is allowed to an examiner on an IR checkride with respect to approaches when the plane can do them but no airfields that require the three required are not in realistic range. (Having a DME installed would be the cheapest way to bypass the issue. But it's a leased plane, so....)

As a reference (and understand that I'm sure every DPE is different), mine let me substitute a VFR-only GPS for a DME. I did ask him first. Otherwise, we would have had to fly about an hour away to find the type of approach I needed...also, often times radar can substitute for DME...

 

[newlangsyne]

You can identify the MAP either by DME or by time and groundspeed. As you say in post #7, the note is just there to keep you from using the wrong DME signal.