How exactly does an NDB work?

[ktulu34535]

During my ground lesson today I was teaching the fundamentals of NDBs (I'm doing my instrument instructor first).

After all was said and done I was asked how exactly the NDB works.

I know how the loop antenna senses everything except whether to and from and the sense antenna makes that determination.

The station sends out a signal and then what? How does the actual antenna work? What is the principle of operation?

I've been looking all over for a detailed explanation on the web, AIM and various other pubs, where can I find a detailed explanation?

 

[VNugget]

http://www.avweb.com/news/avionics/183233-1.html

 

[LittleDeuce]

Do away with the NDB

VNugget's reply was exactly why this forum is invaluable.

But I still think the NDB's time has passed!

 

[B190Captain]

NDB's are certainly a navaid of the past.

 

[Gulfstream 200]

why do they still teach that useless stuff??

NDB's......
If the FMS cant do it, it should not be done.

 

[bobbysamd]

Do not do away with the NDB

I still think the NDB's time has passed!

I disagree.

The orientation and tracking procedures taught for NDB work are excellent training. Think about it. Most anyone can fly a VOR or DME hold. An NDB hold, especially with a fixed-card ADF, requires far more headwork. Moreover, in many parts of the world, and not necessarily those in the third world, NDB approaches are the only ones that are available.

Long live NDBs!

 

[B190Captain]

Re: Do not do away with the NDB

I disagree.

The orientation and tracking procedures taught for NDB work are excellent training. Think about it. Most anyone can fly a VOR or DME hold. An NDB hold, especially with a fixed-card ADF, requires far more headwork. Moreover, in many parts of the world, and not necessarily those in the third world, NDB approaches are the only ones that are available.

Long live NDBs!

You may disagree but it's the truth. NDB's are slowly being decommisioned across the country. It's like flying a 777 with a sextant.

 

[tarp]

I'll agree with Bobby.......

Some day we'll go to a triple red security threat and the Homeland Security folk (motto: " the sky is falling, the sky is falling") will enact the DOD GPS non-selective super-duper algorithm scramble.

Then they will shut the power off in the AFSS's which in turn shuts down all the Localizers and VOR's.

So give me the sextant and the stars - they can't revoke Polaris and give me an NDB. Heck, I can listen to news talk 630 in Washington DC and know that my big fat needle will lead me right to Montgomery Mall on the Beltway. From there I can follow the interstate or the river someplace! I used to carry a little cheat sheet with all the radio station antenna locations and then I could shoot an NDB approach anyplace I wanted. I remember when GAI (maryland) NDB went down for a while, we all just tuned in Radio 1130 (0.7 miles off the end of the runway) and kept doing our NDB-A approaches.

Any kid with MS-Flight whatever can fly a GPS or FMS. Real pilots know how to track an NDB!

And just wait till they privatize the airspace system. Let's see 3.6 billion for a satellite system or $18.00 at Radio Shack for an AM transmitter. If you think they dumped the idea of a $300K pilot fast, just think what the bean counters can do to your airspace!

Too jazzed up on Caffeine tonight. Must get sleep. PS. All of this was just good fun.

 

[cl-65link]

sexton- you mean SEXTANT?

 

[328jetdriver]

NDB's are great, you get to listen to great AM music or a good ballgame. they're not completely useless.