Why is an ADF required?

[HPNPilot1200]

Giving up now.

Welcome to the World Wide Debating ring. Thanks for all of your insight on here, John. I learned a lot from your posts.

How's everything in OKC?

 

[TMetzinger]

Do you people all have John on "ignore" or something??? We have our very own procedure designer right here who told us why, TWICE, and we're still arguing over it.

No, I got John's point. You can't positively identify HOLOE by tracking outbound on the R-084, because you may get false needle centering from the localizer when outside it's service volume. You'd also get the 6.6 DME from I-CBE on two points on the GRV-084 radial. Correct, John?

I assume that at the altitudes involved, the GRV DME isn't reliable enough to identify HOLOE either? Perhaps as GRV084/20?

This looks to me like other approaches that would say ADF or RADAR required, so that ATC could vector you to the fix. If it were in Kansas, without all the pesky mountains and limited low altitude radar coverage, I would expect to see radar vectors being possible. Hmm - maybe someday ADS-B will allow for vectors in this kind of situation.

 

[gismo]

I see nothing that says they are -- no published routing from GRV to HOLOE other than via CBE. And if it isn't published, you can't fly it on your own, which is what SIAP's are supposed to be about.

I have to agree that radar would be required to fly a non-published route (whether or not you have point to point nav) but I don't agree that the lack of a "radar required" note means you couldn't fly such a transition provided you were indeed in radar contact. Now if you flew to this airport without an ADF or approved substitute and radar wasn't available, you'd have to go somewhere else (and you'd better have a legal alternate and associated fuel) but I don't see why you couldn't file this.

Then again, I suppose that if radar was available you might just get vectors to final.

 

[ggroves]

Then again, I suppose that if radar was available you might just get vectors to final.

No radar is available around KCBE under approx. 5,000 ft. This is one of those approaches that you get to fly the full published approach.

Also I agree with Ron...great training approach on paper and in the air. I've used it for student work, IPCs, etc.

Greg

 

[bbchien]

Bruce, you're not saying that you can't substitute IFR GPS for the ADF on this approach, are you? If you are, please explain why.

No, I am not. I reviewed the post. I don't believe I did. The chart does NOT make allowances for an approach cert. GPS, which by notam may be used for nonlateral guidance only- and can't be used to fly the approach primarily.

Since PVT-ASELs, and CFIs get no formal training in TERPS, if it says so ("ADF REQUIRED") it's clearly for a reason even if not evident. The JEPP version says the same thing.

No misprint.

I just get so used to pilots saying things like, "It "can't mean I have to report traffic school for speeding, it can't possibly....." Well, my response to that, and to this is, "Yes it does, the english is plain". So, although the string is about "why" there really is no expertise here to discuss it- except for John Clough, who IS Flightcheck 99. With the collapse of the TERPS board, Wally Roberts has joined the AOPA board as "aterpster"..... and he is clearly qualified to discussed these.

But for the rest of us, it's just, "that the way it IS". In plain english, ADF is required. Never mind why. On form GG, reporting traffic school IS required. It's how it is.

 

[gismo]

But for the rest of us, it's just, "that the way it IS". In plain english, ADF is required. Never mind why. On form GG, reporting traffic school IS required. It's how it is.

If I understand you to be saying that there's no point in trying to understand why any specific requirement applies to an approach, I have to disagree. While it's true that from a purely functional perspective such an analysis is pointless in that understanding the basis of the requirement doesn't remove the requirement, it still seems worthwhile to me if for no other reason than gratification in the quest for knowledge. BTW I never meant to imply that one could legally fly this approach without a working ADF or approved substitute.

And to that end FastNFury, I have couple more questions:

1> Are there any LOC approaches where a VOR radial is the guidance on a transition or intermediate segment which terminates at a fix defined solely by the intersection of the radial and the LOC?

2> What are the acceptable LOC angular limits if the intersection of a LOC with another defined course? IOW how close to the LOC course centerline would a NDB or VOR need to be if the NDB or VOR was providing positive course guidance to the LOC centerline and the LOC center defined the fix along the bearing/radial?

3> Where in the TERPS manual is this defined? I have a PDF copy that was scanned and I cannot search it for words.

 

[flyingcheesehead]

No, I got John's point.

I wasn't pointing it at you - From reading back through the thread, there are posts from Ron, Lance, EdFred, and Troy that lead me to believe they must have missed John's posts somehow.