GPS on an NDB approach

Chief Captain

Chief Captain

Well-Known Member
Hey all, I'm having a brain fart here.

Can you use a GPS to shoot an NDB approach? I'm wondering because an approved IFR GPS can be substituted for an ADF, but I've never actually thought of using the GPS inside the FAF.

Thanks
 
Chief Captain said:
Hey all, I'm having a brain fart here.

Can you use a GPS to shoot an NDB approach? I'm wondering because an approved IFR GPS can be substituted for an ADF, but I've never actually thought of using the GPS inside the FAF.

Thanks
Click to expand...
Technically, no. Unless it's an overlay. So NDB-36 No. NDB or GPS 36, yes. Now if you ACTUALLY do that or not..... Because that ADF is so so much more accurate than the gps.

An example I have to deal with all the time are the 2 approaches into LGD.
NDB - http://155.178.201.160/d-tpp/1212/00591NB.PDF
GPS - http://155.178.201.160/d-tpp/1212/00591R16.PDF

Since I do not have an ADF in my airplane technically I'm not authorized to do the first approach, which is a royal PITA if I'm not coming from the east. Look at where there IAF for the gps is.
 
Who is to say that you can't dial up the ADF for kicks and grins and use the CDI on the GPS for navigation?
 
It really depends on the title of the approach. If it is the NDB 18L, then you need to use the NDB as your primary means of navigation. Using a GPS in OBS mode as "reference" (or even a localizer if the NDB is a compass locator) is totally acceptable too though.

If the approach were the NDB or GPS 18L, then an NDB isn't required, and the GPS can be the primary and only reference as long as the approach is in the GPS database and current.

GPS can be used as a substitute anytime an NDB is required (IAF, MAP, FAF, cross bearing, etc) except for an NDB approach basically.


EDIT - a bunch of people beat me to it
 
Thanks guys. I'm not talking about overlay (NDB or GPS) approaches, just the vanilla NDB approach.

Regarding the GPS database; In all the cases I've seen, all the approaches for that airport (ILS, VOR & NDB) are in the Garmin database, but that by itself doesn't mean you can use GPS for guidance.
 
Chief Captain said:
Thanks guys. I'm not talking about overlay approaches, just the vanilla NDB 09 approach.

Regarding the GPS database; In all the cases I've seen, all the approaches for that airport (ILS, VOR & NDB) are in the Garmin database, but that by itself doesn't mean you can use GPS for guidance.
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This is correct. The NDB only approach will be in the database for use as reference only, and you should get a message saying that each time you load a non-Gps approach
 
tiredcfi said:
Who is to say that you can't dial up the ADF for kicks and grins and use the CDI on the GPS for navigation?
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If it came down to it, I'd rather do that than try and shoot an NDB approach. I was just looking for a legal way to do it since the FAA says we can substitute GPS for an ADF.
 
MikeD said:
Those scary NDB approaches and all........

How difficult is it to just fly the NDB?
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..... how about shooting an NDB partial panel... Do other people find themselves using the ground track function on the GPS vs the wet compass?
 
tlewis95 said:
Using a GPS in OBS mode as "reference" (or even a localizer if the NDB is a compass locator) is totally acceptable too though.
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Yep, which is how we do it at work (NDB approach loaded up in the FMC and flown in LNAV, while monitoring raw data).
 
JDean3204 said:
..... how about shooting an NDB partial panel... Do other people find themselves using the ground track function on the GPS vs the wet compass?
Click to expand...

BTDT in actual, minus the GPS. Whats the difficulty and apprehension here even with doing it full panel? I mean, seriously. If the IAP requires NDB only, then fly the damn NDB instead of trying to urgently find every way to avoid it. What the hell have we come to? Is tracking an NDB course inbound or outbound that much of a rocket science maneuver nowdays, that the current crop of GPS-monkeys need to find every way to avoid it in order to keep their heads from exploding, or actually have to use a brain cell to do something more than mindlessly following a magenta line on a screen?
 
MikeD said:
BTDT in actual, minus the GPS. Whats the difficulty and apprehension here even with doing it full panel? I mean, seriously. If the IAP requires NDB only, then fly the damn NDB instead of trying to urgently find every way to avoid it. What the hell have we come to? Is tracking an NDB course inbound or outbound that much of a rocket science maneuver nowdays, that the current crop of GPS-monkeys need to find every way to avoid it in order to keep their heads from exploding?
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We don't have an ADF in my companies entire fleet of aircraft. They're pretty few and far between, and any airport that has an NDB approach has a gps approach to a lower altitude anyways. Also something I'm noticing, they're not fixing them when they break. They're even taking VOR's offline nowadays. We're losing the pdx vor here soon from what I understand, and that's not exactly a small middle of nowhere airport.
I guess my point is that it's quickly becoming an un-needed skill. I've BTDT to. NDB approaches into box canyons where sometimes the signal is coming from the mountainside instead of the antenna, and all that fun.
 
z987k said:
We don't have an ADF in my companies entire fleet of aircraft. .
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Then none of my comments would apply to you, as you can't play even if you wanted to.

Im talking to those who DO have the capability, who are restricted by an NDB-only approach, and who are trying with complete desperation to find any possible legal way around having to actually use that NDB/ADF and be able to substitute their GPS crutch.
 
well... i dont know how you guys do it, but, our past FOM said simply "Any approach which may be retrieved from the FMS database may be flown via FMS navigation except the final approach segment of an ILS" Now, we did still have to present the ground based info via bearing pointer, to verify that the navaid was functional at the time of the approach.

I'll add, it so long as you have the info provided in the cockpit, it doesn't matter what your "primary" information is. you certainly can couple the autopilot to the gps course in a non GPS NDB, but, you must have the NDB bearing information displayed.
 
MikeD said:
BTDT in actual, minus the GPS. Whats the difficulty and apprehension here even with doing it full panel? I mean, seriously. If the IAP requires NDB only, then fly the damn NDB instead of trying to urgently find every way to avoid it. What the hell have we come to? Is tracking an NDB course inbound or outbound that much of a rocket science maneuver nowdays, that the current crop of GPS-monkeys need to find every way to avoid it in order to keep their heads from exploding, or actually have to use a brain cell to do something more than mindlessly following a magenta line on a screen?
Click to expand...

Generally, I'd prefer to fly the GPS overlay for VOR and NDB approaches. Provided we "monitor" the approach either on the number 2 Nav, or the NDB, we're authorized to do this any time we want by our OpSpecs. Frankly, I like it better -the GPS is wayyyyyyy more accurate, it's pretty much impossible to lose SA, and the chance of screwing the pooch in mountainous terrain is much lower. Accuracy is nice, I prefer the GPS needle to a wildly swinging old-ass NDB in the mountains. While NDB is still my favorite enroute Navaid (it's the simplest to use in my opinion, and I can listen to the radio when I'm navigating by some other system) the GPS approach that overlays an NDB is a much tighter approach.

If I have the equipment to do the "overlay," it seems foolish not to use it.
 
ppragman said:
If I have the equipment to do the "overlay," it seems foolish not to use it.
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The fact that some are desperately trying to find a way to be able to fly the GPS instead of the NDB is what I find irking. Want to do it and can with an approach that allows it? Fine. Trying to find any way to avoid flying the NDB because it's scary or supposedly extremely inaccurate or too much work and brainpower or whatever? Thats sad.
 
Wait, wait, wait, I've seen this regulatory question answered before.

z987k said:
I've BTDT to. NDB approaches into box canyons where sometimes the signal is coming from the mountainside instead of the antenna, and all that fun.
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The tl;dr for MikeD is, "watching the needle for the primary approach navaid oscillate 180 degrees while you're on the final segment isn't cool, man."

None of this is an argument against maintaining the skill, mind you, but when the equipment isn't any good (etc.)...
 
Autothrust Blue said:
None of this is an argument against maintaining the skill, mind you, but when the equipment isn't any good (etc.)...
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Again, a legit excuse, but one which has nothing to do with the main argument. OF COURSE if the particular NDB approach navaid is bad, then don't use it. But that doesn't mean that every NDB is a completely inaccurate POS. NDB approaches are a great skill builder to have and are a great SA as well as instrument pilot skills honing tool. Why so many people want to mindlessly follow some magenta line all the time, something that takes nearly zero skill, is perplexing. No one wants a challenge, or use of some brain power to think, or a sense of accomplishment anymore, when there is a legitimate chance to be able to do it.

One would think that guys here having to fly an NDB approach, are being asked to perform celestial navigation with a sextant or something.....sheesh
 
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