Anyone Still Using ADF/NDB?

Keith Ward said:
I just came across that section in my Sporty's ground school course (I have a PPL, but am getting back into the game after a long time away, so I'm starting from the ground (school) up), and it made me wonder.

It almost seems like these days that VOR is the backup for the GPS (and like many of you, I use the panel-mounted GPS, and then ForeFlight as the backup GPS). But does anyone still use the really old nav stuff? I feel like I *should* learn it, just because, but then back when I was flying before, I promptly forgot all about it once I got my license.

Ultimately, is it still valuable to have that knowledge, or do you believe we've moved on?
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Take a look at charts of Alaska..... low frequency airways are alive and well.
 
Maxnr said:
Back in the last century, I strapped in the back seat of a Nat Guard Birddog as a safety pilot. The front seater (wearing the hood) was one of the four WW2 vets in our unit. The Birddog's only nav gear was a LF receiver with a manual loop. You know, that basketball hoop on the aft fuselage.

CPT "B" Showed me a manual loop NDB approach to the runway that was flawless. More impressive because the bearing selector and receiver controls are all mounted up in the left wing root between pilots.

You haven't seen c**p until you've used DECCA.
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The history of the development of DECCA is fascinating......the British led the way in the development of radio navigation systems (It was either succeed at it or be destroyed by the Germans). The British developed an HF system called "Gee" which, IIRC, was the very first hyperbolic navigation system ever deployed. It was developed under extreme secrecy, and the Germans were baffled for a while after British bombing raids on Germany suddenly became far more accurate than they had been previously. DECCA was essentially a low frequency version of Gee.
 
davidgfern said:
The history of the development of DECCA is fascinating......the British led the way in the development of radio navigation systems (It was either succeed at it or be destroyed by the Germans). The British developed an HF system called "Gee" which, IIRC, was the very first hyperbolic navigation system ever deployed. It was developed under extreme secrecy, and the Germans were baffled for a while after British bombing raids on Germany suddenly became far more accurate than they had been previously. DECCA was essentially a low frequency version of Gee.
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IN retaliation, the Germans developed a system called "Knickbein" (crooked leg) which essentially was a single beam of a four course radio range. Two transmitters at separate locations in Germany (or German occupied territory) transmitted "A" and "N" courses, with the beams steered so that they intersected over Britain at the desired target. German bombers would fly along one radio beam until they crossed the other beam, and dropped their bombs. The British eventually figured out how to jam Knickbein signals, and were able to "bend" the beams to get German planes to fly to locations other than the target, and drop their bombs over areas where no harm would be done.
 
I replaced my NDB with an XM audio receiver. Better for listening to the ball games.
 
I have a fond memory of rockin' to Sounds of Silence on AM radio on the ADF through the crappy cabin speaker going cross country in a rented 172 in the 1970s... only time I switched one on since my PP checkride.
 
Listening to AFVN 69/70, but not during combat assaults. Only when hauling ash and trash all day. Loved that ADF receiver.
 
Piperonca said:
Listening to AFVN 69/70, but not during combat assaults. Only when hauling ash and trash all day. Loved that ADF receiver.
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How about relying big time on the ADF while scud running....and you spot the crew chief's hand sneaking up to switch back to AFVN.
 
Maxnr said:
How about relying big time on the ADF while scud running....and you spot the crew chief's hand sneaking up to switch back to AFVN.
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No worries there - Chu Lai had no NDBs, nor did anywhere near. Compass and clock, map and eyeballs. No TACAN. Head east, you get the ocean; head west, you get the mountains. ADF was entertainment only.
 
brien23 said:
You need to get your money back from your instruction as you clearly do not understand the use of a NDB approach in actual IMC to Mins.
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Last NDB approach I shot was in the right seat of a T-47 in 1987.

Any instructor that even teaches them is wasting your time and money. There is a lot to learn in the PPL and instrument rating. There is no reason to teach things that do not advance your skills and knowledge but do spend your money. Far better that an instructor introduces an RNAV or ILS approach to a student than the NDB. In fact, I can make a case for an RNAV/ILS actually being good for student to learn a stabilized approach.
 
FlyBoyAndy said:
Are ADF/NDB only used for approaches or navigation too? I've just never used them or was with anyone that has, I think.
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Plano Pilot said:
If you look over near ILM there are still two ADF’s, CLB & DIW, with AR routes for running to S Florida and the Bahamas. These are more powerful stations that give a longer range than VOR’s. Back in the day I used them and GLS, near Galveston, when crossing the water.
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Navigation too... But that's even rarer than the approaches!

At one point in time, there were "colored" airways. I don't know if the colors had any meaning, but there are still a couple down in the Florida Keys off the Marathon NDB (B9 and B646 - "Blue") that are in operation. There's a charted segment of G13 ("Green") in the Outer Banks off the MQI (Manteo) NDB, but that one has apparently been decommissioned.

There's a couple of others using coastal NDBs in between that head out to sea, probably because the lower-frequency signals can propagate a bit better around the curvature of the earth. It looks like G13 probably once connected to L452 (toward Turks and Caicos) and M325 (to Bermuda) at OXANA at one point, though I'm not sure how those routes would have been defined prior to GPS.
 
There was a single NDB remaining near us when I did my IR. We did the approach a few times, just mucking about, on several flights. . .always ended up offset about 1/2 a mile, even though the NDB was on the field. I just figured we sucked at NDB, but my CFII pursued it, and the feds decided it was, in fact, in need of service. Which never happened, and it went away.
 
Sundancer said:
There was a single NDB remaining near us when I did my IR. We did the approach a few times, just mucking about, on several flights. . .always ended up offset about 1/2 a mile, even though the NDB was on the field. I just figured we sucked at NDB, but my CFII pursued it, and the feds decided it was, in fact, in need of service. Which never happened, and it went away.
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Well, TBH you probably sucked at it too... ;) An NDB is, as the name says, non-directional. There's nothing about it that can affect where you end up, provided you're receiving the signal properly. Now, the airplane may have been screwed up somehow and indicating incorrectly. Were you always offset the same 1/2 mile?

Of course, the other possibility is that everything was working fine and the approach is actually supposed to work that way. They can have a pretty big offset - 20 degrees, maybe? - before they get a letter instead of a runway number.
 
flyingcheesehead said:
Well, TBH you probably sucked at it too... ;) An NDB is, as the name says, non-directional. There's nothing about it that can affect where you end up, provided you're receiving the signal properly. Now, the airplane may have been screwed up somehow and indicating incorrectly. Were you always offset the same 1/2 mile?

Of course, the other possibility is that everything was working fine and the approach is actually supposed to work that way. They can have a pretty big offset - 20 degrees, maybe? - before they get a letter instead of a runway number.
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There could have been a systematic error due to distortion of the loop antenna pattern because of where it was installed on the aircraft..... there also could have been some anomalous propagation effects resulting from the topography around the airport----- hills or other tall metallic structures that act as electromagnetic scatterers that alter the phase center of the transmitting antenna.
 
flyingcheesehead said:
Navigation too... But that's even rarer than the approaches!

At one point in time, there were "colored" airways. I don't know if the colors had any meaning, but there are still a couple down in the Florida Keys off the Marathon NDB (B9 and B646 - "Blue") that are in operation. There's a charted segment of G13 ("Green") in the Outer Banks off the MQI (Manteo) NDB, but that one has apparently been decommissioned.

There's a couple of others using coastal NDBs in between that head out to sea, probably because the lower-frequency signals can propagate a bit better around the curvature of the earth. It looks like G13 probably once connected to L452 (toward Turks and Caicos) and M325 (to Bermuda) at OXANA at one point, though I'm not sure how those routes would have been defined prior to GPS.
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It is politically incorrect to refer to those low frequency routes as "colored" ------ they should be referred to as "African American" airways.......
 
davidgfern said:
It is politically incorrect to refer to those low frequency routes as "colored" ------ they should be referred to as "African American" airways.......
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...and since having separate airways is segregation, NDBs and VORs should be able to use the same airways.
 
dans2992 said:
You should be somewhat familiar with it, but I can tell you, I would never trust it enough to do an NDB approach in actual IMC to mins (without GPS overly or backup).

I know my skills, and NDB approaches are not one of my strong ones!!

The think DME arcs might also be getting long in the tooth. Never did them in training (probably because there weren’t many around Chicago, or my instructor overlooked them).
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At least NDB mins arnt normally that low anyways ;)

Pugs said:
Last NDB approach I shot was in the right seat of a T-47 in 1987.

Any instructor that even teaches them is wasting your time and money. There is a lot to learn in the PPL and instrument rating. There is no reason to teach things that do not advance your skills and knowledge but do spend your money. Far better that an instructor introduces an RNAV or ILS approach to a student than the NDB. In fact, I can make a case for an RNAV/ILS actually being good for student to learn a stabilized approach.
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I’d say that shooting a NDB and navigating NDB/VOR without moving map or GPS is a great thing to build situational awareness, toss in a ILS and a hold or two off a NDB or VOR intersection and that’s a great test of knowing where you are and where you’re heading.

Personally I’d do that stuff in a sim though to save money and to be able to time warp from point to point after established on a airway.
 
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flyingcheesehead said:
Navigation too... But that's even rarer than the approaches!

At one point in time, there were "colored" airways. I don't know if the colors had any meaning, but there are still a couple down in the Florida Keys off the Marathon NDB (B9 and B646 - "Blue") that are in operation. There's a charted segment of G13 ("Green") in the Outer Banks off the MQI (Manteo) NDB, but that one has apparently been decommissioned.

There's a couple of others using coastal NDBs in between that head out to sea, probably because the lower-frequency signals can propagate a bit better around the curvature of the earth. It looks like G13 probably once connected to L452 (toward Turks and Caicos) and M325 (to Bermuda) at OXANA at one point, though I'm not sure how those routes would have been defined prior to GPS.
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I recall reading a bunch of years ago that the colors denoted the primary orientation of the airway..... north-south routes were one color, east-west routes were another color, and diagonal routes were a third color (blue, magenta, and Amber, I think).
 
davidgfern said:
I recall reading a bunch of years ago that the colors denoted the primary orientation of the airway..... north-south routes were one color, east-west routes were another color, and diagonal routes were a third color (blue, magenta, and Amber, I think).
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Red and Green are East/West, Amber and Blue are north/south. Ref. AIM 5-3-4(a)(1)(b).
 
A555 (Amber) is still the main route from Florida to the Turks and on to Puerto Rico.
 
The last time I flew an airplane with an ADF receiver was in 1994 in a rented TB-21 Trinidad to AirVenture and back. We only used it to listen to AM broadcast for entertainment, and the country music and hellfire & brimstone preachers got pretty boring.

These days my nav backup to the panel mounted GPS is VOR, and the backup to that is the Avare app on my Android cellphone. I carry current paper charts if everything else goes TU.
 
flyingcheesehead said:
Well, TBH you probably sucked at it too... ;) An NDB is, as the name says, non-directional. There's nothing about it that can affect where you end up, provided you're receiving the signal properly. Now, the airplane may have been screwed up somehow and indicating incorrectly. Were you always offset the same 1/2 mile?

Of course, the other possibility is that everything was working fine and the approach is actually supposed to work that way. They can have a pretty big offset - 20 degrees, maybe? - before they get a letter instead of a runway number.
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Always offset to the right, on runway heading (no angle off), about 1/2 mile, perhaps a bit less. I put it down to my technique or the aircraft receiver, or some of both. The distance was consistent. My CFII tried it with another aircraft, same result, then called about it. As I recall, it went out of service, and wasn't brought back on line again. Maybe an oddity of propogation, as someone suggested. . .
 
Sundancer said:
Always offset to the right, on runway heading (no angle off), about 1/2 mile, perhaps a bit less. I put it down to my technique or the aircraft receiver, or some of both. The distance was consistent. My CFII tried it with another aircraft, same result, then called about it. As I recall, it went out of service, and wasn't brought back on line again. Maybe an oddity of propogation, as someone suggested. . .
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Yeah, kinda sounds that way. What was the approach?
 
I don't even know of any airports remotely near me that have NDB approaches. In today's day and age, there really is no reason to have an ADF anymore, sparing the football games or other interesting things you can pick up on AM radio. Even a non-WAAS 430 will get you into RNAV approaches, which are a heck of a lot more precise and easier to learn and fly.
I've also only rented maybe 2 or 3 planes with the ADF receivers still installed. The few pounds of saved weight seems to be a justified trade.
But heck, on the strand of old navigation, I have flown a plane with a LORAN in it. No idea if it would even power on, the electrical system on the plane was weak enough with only lights burning, but it was still installed. Talk about a timehop.. That technology predates my age rather significantly.
 
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