wayneda40
Line Up and Wait
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waynemcc
Indeed an excellent question, and I'm also curious. I certainly don't have a definitive source for my understanding (that GPS can be primary while monitoring the LOC on CDI-2), but I'm certainly not going to fly with a LOC Backcourse on a reverse-sensing CDI as primary. Call me lazy or call me chicken, but for safety (and sanity) reasons I'd look for another approach or alternate destination . Hoping someone has a legal reference on this.Good video but one question - when flying the LOC BC, are you allowed to rely on GPS for primary nav while monitoring the LOC on nav2? I know that’s ok per AIM 1-2-3 for VOR, DME approaches. Example - you can have the VOR tuned on nav2 while using GPS for primary nav. But I thought for LOC and ILS approaches you had to have raw LOC/GS data as primary. Not arguing the point, just legitimately curious.
Reverse sensing isn’t that big a deal once you’ve done it a few times. Practice it a little. There’s probably lotsa times traffic will allow you to track the HABUT FOUR out of SBA when you’re heading out west. You can do it with just about any Localizer up at altitude with out doing an Approach. Just dial it in and practice flying away from the needle instead of into it.Indeed an excellent question, and I'm also curious. I certainly don't have a definitive source for my understanding (that GPS can be primary while monitoring the LOC on CDI-2), but I'm certainly not going to fly with a LOC Backcourse on a reverse-sensing CDI as primary. Call me lazy or call me chicken, but for safety (and sanity) reasons I'd look for another approach or alternate destination . Hoping someone has a legal reference on this.
Thanks for posing the question,
Wayne
Excellent idea... the "fun" disappears in my aircraft (DA40/G1000) as the HSI "reverses" the reverse sensing .Reverse sensing isn’t that big a deal once you’ve done it a few times. Practice it a little. There’s probably lotsa times traffic will allow you to track the HABUT FOUR out of SBA when you’re heading out west. You can do it with just about any Localizer up at altitude with out doing an Approach. Just dial it in and practice flying away from the needle instead of into it.
FWIW, this was my comment to Wayne on the LOC-BC issue in another group. It's expanded with some of the text of the references.
One thing to consider is whether we actually may fly a LOC/LOC-BC approach with GPS, just monitoring the raw data. Many would say substitution for a LOC FAC is in the same category as substitution for ILS - must have that selected in the primary CDI/display.
The language in AIM 1-2-3(c) referring to LOC raw data is in the general section.
View attachment 92139
The section which authorizes monitoring on the FAC does not mention localizers.
View attachment 92140
I forget which unit Levi has on board, and the language varies, but here what the GTN AFMS Limitations section says on the subject, pointing out the difference:
"When using the Garmin LOC/GS receivers to fly the final approach segment, LOC/GS navigation data must be selected and presented on the CDI of the pilot flying. When using the VOR or ADF receiver to fly the final approach segment of a VOR or NDB approach, GPS may be the selected navigation source so long as the VOR or NDB station is operational and the signal is monitored for final approach segment alignment. "
(The Diamond G1000 Limitations is fuzzier. The GNS language was never updated and is even more restrictive). And, of course, there are those who would say it's much ado about nothing. That you can fly anything using GPS so long as the primary raw data is displayed in some way and the language added to authorize it was unnecessary to begin with.
If you are old enough to remember, Red Skelton's standard line after a bad joke was, "I just say 'em. I don't explain 'em." Not the best use of language, eh? My guess is it's "the CDI" being fed by the Garmin unit. Roundabout way of saying, "push the CDI button so VLOC is annunciated."Whadda they mean by “...When using the Garmin LOC/GS receivers to fly the final approach segment, LOC/GS navigation data must be selected and presented on the CDI of the pilot flying...” I’ve flown more than one airplane that has an HSI(built in ‘CDI’) and one or two other ‘CDI’s’ all right there in the panel in front of the left seat. Wouldn’t it make more sense if that said ‘a’ CDI of the pilot flying instead of ‘the’ CDI of the pilot flying?
If you are old enough to remember, Red Skelton's standard line after a bad joke was, "I just say 'em. I don't explain 'em." Not the best use of language, eh? My guess is it's "the CDI" being fed by the Garmin unit. Roundabout way of saying, "push the CDI button so VLOC is annunciated."
Then you wouldn't be "When using the Garmin LOC/GS receivers to fly the final approach segment," so they don't care?Makes sense and follows the logic. But let’s what if it a little. You have say a GTN625 or GNS 400. Stand-alone GPS Navigator. No VLOC.