Help on NDB's

[Bruce]

Top of the day to all. I was flying one of the mission in a.. i think its a 737,, to London where one of the passenger had a heart attack and had to divert to Rotterdam airport. I was given the frquency for the NDB but dont know how and where to enter it and what guage to follow to that NDB. I did made to the airport because i had the direction compass on but i would like to turn it off and still get to the airport....Can any of the experts tell me how and where to input the frequency and what guage to follow to the NDB, and if i should have the switch  set NAV or GPS...Any help is apreciated.

[Dr.bob7]

first use a C172 to practice, (I love small airplanes plus im not sure where the ADF is in the 737 (Automatioc Direction Finder) in the C172 on your radio panel youll see a frequency 284.0 that is your ADF Frequency switch it to the NBDs given frequency and the compass with the thickorange arrow will move the arrow will stop on a heading, now find your magnetic compass heading and add that to ADF heading when you find the sum of the two lets say 249 Degrees you would turn to 249 Degrees

Ex:
Magnetic Compass: 030
ADF Arrow: 090
Your heading to the NDB: 120

(NDBs also have DME equpment)


ADF is relativly old now and isnt required to pass flight school so these might be gone within the next ten years

[Dr.bob7]

from your post i probly didnt need to explain how it works but hoped it helped

[Brett_Henderson]

Start here  :)  http://www.simviation.com/cgi-bin/yabb2/YaBB.pl?num=1208113107



You can skip ahead to part 5.1  (flying to an NDB), but it would be a good idea to start at the beginning  ;)

[dave3cu]

A simple explanation...

NDB freq is tuned on the ADF reciever.

The direction to the NDB is read on the ADF indictor. In the 737 the gauge is a dual needle RMI (Tooltip identifies it as the 'Backup VOR/ADF Indicator) located between the MFD and EICAS. 2 selectors allow you to select either of the needles to display ADF. An ADF needle simply points to the NDB, relative to your ac current heading.

[Bruce]

Just got back from lunch i am at work....Thanks for all the replys i will try your suggestion when i get home

[Brett_Henderson]

(NDBs also have DME equpment)

DME recievers require DME transmitters, that are asociated with a VOR, and some ILS, and some are stand-alone DME (tuned in on a standard NAV reciever).

I've yet to come across an NDB that transmits DME info, or even an ADF reciever that works with a DME.

If there is such a beast, I'd like to learn about it..

[macca22au]

No there is no such beast.  However airports like YARM in Australia still have an NDB but with a quite separate DME transmitter which is tuned like a VOR and provides  distance readouts.  Normally a VOR combines the two functions in the same frequency.

It means that timed holding patterns and descents using the NDB are replaced by accurate distance.  (However GPS approaches are replacing these now).

They are two separate installations.

On its own the NDB and the ADF receiver in the plane is a fantastic training instrument.  The ADF is a bird dog, all it ever does is point to the station.  It means the pilot is constantly adjusting for cross-winds, and when manuoevring is doing constant mental arithmetic.  I learned to add and subtract 180deg off any heading in a flash when using the NDB.

FSX is a great device for trying out the NDB.  And remember when you are making an approach in IMC you must have the audio turned up - the morse code (which we had to learn) identifier was the only way we knew the transmitter was working.  No sound, missed approach.  You can bet your life our instructors regularly turned it off.

[Brett_Henderson]

Yeah..  I cover tracking an NDB with wind in part 5.1...

The best single use for an NDB ?  (see my avatar text)...  It's a great reference to keep you from turning final too early (or too late) on an ILS approach. And being that close to an airport, it can double as a homing beacon. I'm gonna miss NDBs  

[Dr.bob7]

my mistake about the DME ive only used a NBD once on the sim and i think i was also tracking a VOR radial so i might of remembered the DME being set so my mistake

[macca22au]

Brett, you're right.  

Pilots of heavy jets doing training circuits use the on-field NDB to judge when to turn base.  When the needle falls to 45degs they can commence the turn.   It would work on  a quick smaller aircraft as well.  

But in your beloved C172 just about the end of the runway on downwind is about right!  No instruments needed.

In Australia the NDB is still very common.  Aircraft fly over great distances sometimes between Navaids, and the NDB was the cheapest to install.  Sometimes even we tuned an AM radio station through the ADF receiver - and as long as it was identifiable from station announcements it could be used for tracking purposes.  In thunderstorms the ADF was a lightning tracking device and useless for navigation.  

However I'm not up with modern stages in nav development in Australia but the GPS either installed (TSOd) or a portable device have taken over as the primary instrument.  (We can have 150 miles between ground stations in desert country). Most official fields with an NDB also have a published GPS approach.  Also it is clear that unofficially farmers and others who fly from property strips develop there own totally unofficial GPS approaches.

But you can't stop ingenuity in a big country.

[Brett_Henderson]

[quote]Brett, you're right.

[BillG]

Even better, some of the WAAS capable GPS units now include terrain avoidance, so you don't have to worry about flying into things :-) At least that's the way in the real world, in FSX I don't think you have this.

[macca22au]

Again in Australia we have some airports like Cairns where there are published WAAS approaches and departures that allow aircraft to take much more direct tracks, with absolute guidance between terrain.  It saves time and money for the airlines in a big way.

Cairns is tropical so in summer during the monsoon rain and cloud are standard, so the overall savings are large.

Now all we need is Navigraph or someone to bring them into the sim, as these are very much the coming thing.  The waypoints have quite different designators from the standard SID, STAR and enroute forms.

[macca22au]

And yes Brett, once upon the NDB as an ILS marker was common, and there is nothing more comforting than seeing that needle swing and know you are in the funnel.

I did my initial Instrument Rating in a C172 and in those days the nearest ILS was at Sydney International.  Imagine going down the glideslope at 90kts with jets behind.  On one occasion an Air NZ heavy was vectored around me and back on to final with some smart remarks from ATC and a word of encouragement from the ANZ pilot.

Ah, those were the days.  Now that is prohibited unless it is a full-on ILS to a landing - and the landing fees are now about half the capital value of the aircraft so effectively lighties have been pushed out.