GPS or Vloc VOR DME approach on checkride

I am sure you can use the GPS to identify the Step Down Fix and the Missed Approach Point if they "load up." In other words BUYAB and the MCN 8.8 DME are Waypoints appearing on the GPS. If they are not, then you must get DME from MCN to identify BUYAB and you may either time the Missed Approach Point or use DME from MCN. Why one would choose to time it when DME is available I don't know, but it would be 'legal.' As far as why BUYAB would not appear as a Waypoint when you "load the Approach" I have heard that some sources, like Jeppessen have quit using fixes inside the FAF in their databases to save storage room.

There are a variety of ways to determine the fixes. You can use the approach data which contains all of the needed fixes, or you can set the to waypoint on the GPS to MCN and use 6.0 GPS distance to identify BUYAB and 8.8 GPS distance to identify the MAP. Jeppesen primarily does not include the step down fixes for a full ILS that are needed for the Localizer only version of the procedure. Garmin splits then into an ILS procedure and a Localizer procedure.
 
I would like to revisit this discussion. The OP talks about timing as an option on this approach however many VOR/DME approaches are based solely off distance and there is no timing chart. In such a case, obviously you must use distance. To utilize the GPS as a DME substitute, would you enter the approach and monitor the GPS for distance while flying the VOR radial on VLOC or would you need to enter the VORTAC identifier directly into the GPS, press go Direct TO, to be able to use the distance reading while tracking the radial on VLOC. I realize the answer may be either is allowed and then I would guess it would come down to if its reading in the right direction (up or down).
You can monitor the GPS for distance. Distance to BUYAB and then distance to the MAP. When you cross MCN the GPS sequences to the next waypoint which is BUYAB and you will be 6 miles from it. When you cross BUYAB the GPS will sequence to the next waypoint which is the MAP, you will be 2.8 miles from it. Halfway there it wil say 1.4 to go. This would coincide 7.4 from MCN but you don't have to do the math. Just before you get to the MAP it will say .1 to go, now 8.7 from MCN. This is of course if your GPS unit loads the fixes inside the FAF. In other words you don't have to monitor your distance from the DME source if the GPS loads the fixes and tells you when you are over them.
 
There are a variety of ways to determine the fixes. You can use the approach data which contains all of the needed fixes, or you can set the to waypoint on the GPS to MCN and use 6.0 GPS distance to identify BUYAB and 8.8 GPS distance to identify the MAP. Jeppesen primarily does not include the step down fixes for a full ILS that are needed for the Localizer only version of the procedure. Garmin splits then into an ILS procedure and a Localizer procedure.
Yeah. You can even do that with Localizer/DME's. Load up Direct to "I" whatever the identifier is and you will get distance from the Localizer/DME antennae. Can't really think of why you would except when the "unit" won't load the approach and you want to use it instead of a DME reciever.
 
Yeah. You can even do that with Localizer/DME's. Load up Direct to "I" whatever the identifier is and you will get distance from the Localizer/DME antennae. Can't really think of why you would except when the "unit" won't load the approach and you want to use it instead of a DME reciever.
There are other places where a localizer’s DME signal is used. For example, the MSP Class B airspace rings are measured from the I-MSP DME. I just wish the localizers would be listed in the nearest VOR page on my 430W. I use that page as a DME substitute rather than direct-to the VOR. That way I don’t have to interfere with my flight plan or loaded approach (and associated missed approach) to get DME information. But I can’t figure out any way to measure DME from a localizer other than direct-to.
 
There are other places where a localizer’s DME signal is used. For example, the MSP Class B airspace rings are measured from the I-MSP DME. I just wish the localizers would be listed in the nearest VOR page on my 430W. I use that page as a DME substitute rather than direct-to the VOR. That way I don’t have to interfere with my flight plan or loaded approach (and associated missed approach) to get DME information. But I can’t figure out any way to measure DME from a localizer other than direct-to.
Hmm. I wouldn't think that using the distance to a VOR on the 'Nearest Page' would qualify as an authorized substitute for DME but who knows. If the Nearest Page updates frequently enough, why not?
 
Hmm. I wouldn't think that using the distance to a VOR on the 'Nearest Page' would qualify as an authorized substitute for DME but who knows. If the Nearest Page updates frequently enough, why not?
It's updated continuously. I don't know of any regulation or interpretation relating to using GPS to substitute for DME that requires you to set your equipment to navigate to the navaid. On the 430, you would have to have it as your next flight plan waypoint (using direct-to or otherwise) in order to get a distance read-out. Using the NRST chapter, VOR page in the 430 gives you the quickest access to the substitute DME information with no interference with your flight plan.

Granted that actual use of DME in the GPS era is going to be for an approach at least 90% of the time, and by having the CDI track the VOR radial (the topic of this thread) and keeping the approach loaded in the GPS, the 430 will just tell you when you you are at the relevant DME fixes so you don't have to worry about any of this.

With the 530 or the 650/750, life is even easier. Tune the VOR and you get a read-out of the radial and distance. (The 530 has it on the main screen in the VOR tuning box. If I remember right, not having used either model in a while, the 650 and 750 require you to set up one of the display boxes on the main screen.) But on the 430, I haven't found a more efficient way to get substitute DME information than turning the outer knob all the way to the right and then the inner knob a couple clicks to the NRST VOR page.
 
There are other places where a localizer’s DME signal is used. For example, the MSP Class B airspace rings are measured from the I-MSP DME. I just wish the localizers would be listed in the nearest VOR page on my 430W. I use that page as a DME substitute rather than direct-to the VOR. That way I don’t have to interfere with my flight plan or loaded approach (and associated missed approach) to get DME information. But I can’t figure out any way to measure DME from a localizer other than direct-to.
In any of the Garmin units that have an EHSI, you make IMSP the active waypoint an the RMI will handle it like a VOR/DME.
 
In any of the Garmin units that have an EHSI, you make IMSP the active waypoint an the RMI will handle it like a VOR/DME.
That's what I meant, sorry if I bungled on communicating it. Actual VORs conveniently show up in the NRST VOR page, but localizers don't, so you have to make the localizer your active waypoint to get substitute DME information. Like I said in a follow-up post, in the GPS era it has become a corner case to ever need a DME measurement except on an approach and then you will have the approach loaded into your navigator anyhow. But if you want DME to a localizer facility that you aren't flying toward, you have to sacrifice the flight plan in your navigator to get that information.
 
Electronic Horizonal Situation Indicator. The classic one is the Sandel, though there are others now (Aspen, etc...)>
 
The scenario that I'm thinking of here that might happen is that I'm not at the FAF yet and he covers the GPS which has my DME. In that case, I'm thinking that I can track the TO radial to the VOR, turn etc, but without the GPS I have no DME.

In that case, is using the switch of TO/From to start the MAP timer acceptable? It would also make finding my missed hold fix impossible if that is based off of DME from the FAF/VOR.
Well, if he covers the GPS, you just lost your DME unless you have another separate DME receiver. It's a VOR -A DME, no DME/GPS, no approach.

Fly to the VOR and fly the PT with GPS, back at the VOR and FAF inbound, make sure the selector is to CDI or OBS and the correct radial is dialed on the CDI.
 
Well, if he covers the GPS, you just lost your DME unless you have another separate DME receiver. It's a VOR -A DME, no DME/GPS, no approach.

Fly to the VOR and fly the PT with GPS, back at the VOR and FAF inbound, make sure the selector is to CDI or OBS and the correct radial is dialed on the CDI.
It's just a VOR-A approach. KMAC. DME will let you identify BUYAB to get lower minimums. You're also welcome to use it for the Missed Approach Point. The Missed Approach Fix is both an intersection and a DME Fix so you're also welcome to use DME there.
 
It's just a VOR-A approach. KMAC. DME will let you identify BUYAB to get lower minimums. You're also welcome to use it for the Missed Approach Point. The Missed Approach Fix is both an intersection and a DME Fix so you're also welcome to use DME there.
Jeppesen codes the MAP as MA028, FWIW.
 
Jeppesen codes the MAP as MA028, FWIW.
Yeah. Thats got me wondering. On the Approaches that Jeppesen has chosen not to include stepdown fixes inside of the FAF to save storage space, is 'MAxxx' still there? I'd think so, but..
 
Yeah. Thats got me wondering. On the Approaches that Jeppesen has chosen not to include stepdown fixes inside of the FAF to save storage space, is 'MAxxx' still there? I'd think so, but..
Yes it is.

When it comes to ILS or LOC procedures if you buy your database from Garmin it will have the LOC as a separate procedure with final segment step-down fixes if there are any. Not so if the database is purchased from Jeppesen.
 
Yes it is.

When it comes to ILS or LOC procedures if you buy your database from Garmin it will have the LOC as a separate procedure with final segment step-down fixes if there are any. Not so if the database is purchased from Jeppesen.
Now that is interesting!
 
Now that is interesting!
They plan to have the LOC procedures separated in the Jeppesen in the future, for avionics that are not memory limited. Garmin presently does it for its Americas subscription, because that doesn't overload database memory, even on older units that are limited to 20 megs.
 
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