NDB's, do I have it right?

[Bill]

OK, flying your approach inbound heading TO the station:

Say your right of course on approach heading, and the needle is 10 degrees left of the nose (RB350). I would then turn left 20 degrees and fly that heading. The needle would, during the turn, swing up thru the nose and then end up 10 degrees right (RB010) after the turn. I would then fly heading until the needle is 20 degrees right (RB020), and then turn 20 degrees right back to inbound published heading. If I did everything right, when I roll out the needle should be on the nose (RB360), correct?

Ok, flying from the station:

Say you are left of course on approach heading, and the needle is showing 10 degrees right of the tail (RB170). I would turn 20 degrees right, and when I roll out, the needle should be 30 degrees right of the tail (RB150). I fly that heading until the needle is dragged 10 degrees back towards the tail until the needle is 20 degrees right of tail (RB160), and then turn left 20 degrees back to approach heading. If I did everything right, the needle should then be on the tail (RB180).

Is this it?

 

[Dave Theisen]

That's correct

 

[Let'sgoflying!]

My cfi-ia used to say something like
"Make the needle deflection equal to the course correction applied", as an easier way to say what you are describing.

Only thing to add to your description is: Now, what heading correction to apply stay on course? (likely you were being blown off course and need a crab angle to avoid that now)

 

[Bill]

Only thing to add to your description is: Now, what heading correction to apply stay on course? (likely you were being blown off course and need a crab angle to avoid that now)

I'd try half of the initial course correction and see how that goes. (ie, if I turned the 20 degrees to get back on course, try 10 degrees into the wind once I'm corrected and back on course)

 

[Bill]

My cfi-ia used to say something like
"Make the needle deflection equal to the course correction applied", as an easier way to say what you are describing.

Right, but the trick is its slightly different tracking to station vs tracking from station.

 

[poadeleted20]

OK, flying your approach inbound heading TO the station:

Say your right of course on approach heading, and the needle is 10 degrees left of the nose (RB350). I would then turn left 20 degrees and fly that heading. The needle would, during the turn, swing up thru the nose and then end up 10 degrees right (RB010) after the turn. I would then fly heading until the needle is 20 degrees right (RB020), and then turn 20 degrees right back to inbound published heading. If I did everything right, when I roll out the needle should be on the nose (RB360), correct?

Your system works only in a zero-wind situation. You could fly forever and not see that happen if there's enough wind from your left that put you off the desired bearing in the first place.

For that reason, I usually teach using double the correction, i.e., turning three times the error angle, and then leaving half the error angle in as a correction for the wind that blew you off in the first place. In this case, assuming the desired bearing off the station is 180 (360 course to the station), and you're on the 170 bearing (350 RB), I'd turn 30 left to 330 heading (initially giving a 020 RB), and hold that until the RB swings right to 030, then turn right to 355 heading (showing RB 005) and see if that takes care of the wind. You can fine tune from there.

In all cases, I teach putting the needle twice the original error over to the other side, i.e., initial turn of three times the original error.

 

[Bill]

In all cases, I teach putting the needle twice the original error over to the other side, i.e., initial turn of three times the original error.

OK, my guy is teaching two times the original error, but I can see where in high wind that might not be enough to get you back on course. Although if you try twice, and see the needle is not moving, or is moving too slowly, you could then add in the extra.

 

[spiderweb]

The better your SA the better you'll do this. With deference to Cap. Ron (who helped me greatly on this), tripling the correction works fast, but you also have to be fast, if you are close to the NDB. IOW, if you are way off on a PT, you might consider calling ATC and requesting another PT (or HPilPT).

Do remember what was said above: "When deflection = correction, you are on course." That is true, no matter what. Now, what you do once you are on course depends on what you are trying to do. So, say it with us,

"When deflection = correction, I am on course"
"When deflection = correction, I am on course"
"When deflection = correction, I am on course"

Amen.

 

[Ed Guthrie]

People seem to forget that you can watch the ADF for needle movement (or lack of) and rate of movement in order to give yourself real time feedback as to approximately appropriate wind correction heading (needle frozen even if off desired point) and quality of correction (needle moving towards where you need it to be at a reasonable rate to happen in your lifetime or not).

 

[Bill]

People seem to forget that you can watch the ADF for needle movement (or lack of) and rate of movement in order to give yourself real time feedback as to approximately appropriate wind correction heading

Thanks, Ed. I've found this to be real helpful on VOR approaches as well, not just needle displacement, but the rate it is moving.

 

[Tom-D]

I'd try half of the initial course correction and see how that goes. (ie, if I turned the 20 degrees to get back on course, try 10 degrees into the wind once I'm corrected and back on course)

The thing that broke the code for me was when I finally figured out the needle is pointing to where you should be..

 

[spiderweb]

The thing that broke the code for me was when I finally figured out the needle is pointing to where you should be..

I hate to do this, but I should point out that this isn't always correct. (Think flying outbound on an NDB approach.)

 

[Ed Guthrie]

I hate to do this, but I should point out that this isn't always correct. (Think flying outbound on an NDB approach.)

In bound or outbound, machts nicht. Needle left, course is left. Needle right, course is right, except...

Where the theory actually tanks is in an x-wind. In that case you could be holding an x-wind correction with needle on one side of nose/tail & desired course is the other side of nose/tail.

 

[spiderweb]

In bound or outbound, machts nicht. Needle left, course is left. Needle right, course is right, except...

Where the theory actually tanks is in an x-wind. In that case you could be holding an x-wind correction with needle on one side of nose/tail & desired course is the other side of nose/tail.

I was pointing out that the comment "the needle is pointing to where you should be," is not correct. If you are flying outbound away from the station, the needle is pointing to the station. You don't want to be at the station.

Good point about the crosswind correction. Again, though, the original statement that "when the correction = deflection, you are on course" still holds true. In this case, though, you don't change your correction; you hold it (crabbing).

 

[Ed Guthrie]

I was pointing out that the comment "the needle is pointing to where you should be," is not correct.

I suspect Tom meant that statement in a relative left/right perspective, not front/rear. YMMV.

 

[RobertGerace]

Guys...

I have a question. Does any of this matter?

I've spent about 4 hours over the last couple of weeks ripping all the NDB approaches out of my Jepp binders. I mentioned it to my instructor at SimCom and he told me that the FAA is decommissioning all of the NDB approaches.

 

[wsuffa]

Guys...

I have a question. Does any of this matter?

I've spent about 4 hours over the last couple of weeks ripping all the NDB approaches out of my Jepp binders. I mentioned it to my instructor at SimCom and he told me that the FAA is decommissioning all of the NDB approaches.

Well, not quite right.

FAA is decommissioning a lot of the NDB approaches. Airports that have alternate non-GPS approaches are the first to go. For example, KSAT is having it's NDB approaches eliminated - they're never used because the ILS is used instead. If NDB is the only approach, it's pretty safe to stay.

There's a complete list somewhere of the approaches that are listed for elimination.

 

[Let'sgoflying!]

I've spent about 4 hours over the last couple of weeks ripping all the NDB approaches out of my Jepp binders.

You will enjoy your FAA charts, Bob. (get the bound ones unless you want a IAP-snowstorm in your cockpit/on the ramp from time to time.)

 

[ScottM]

OK, flying your approach inbound heading TO the station:

Say your right of course on approach heading, and the needle is 10 degrees left of the nose (RB350). I would then turn left 20 degrees and fly that heading. The needle would, during the turn, swing up thru the nose and then end up 10 degrees right (RB010) after the turn. I would then fly heading until the needle is 20 degrees right (RB020), and then turn 20 degrees right back to inbound published heading. If I did everything right, when I roll out the needle should be on the nose (RB360), correct?

Ok, flying from the station:

Say you are left of course on approach heading, and the needle is showing 10 degrees right of the tail (RB170). I would turn 20 degrees right, and when I roll out, the needle should be 30 degrees right of the tail (RB150). I fly that heading until the needle is dragged 10 degrees back towards the tail until the needle is 20 degrees right of tail (RB160), and then turn left 20 degrees back to approach heading. If I did everything right, the needle should then be on the tail (RB180).

Is this it?

In a zero wind situation, you go it excpet for one littel detail. Plug that NDB into your GPS and fly that course instead ;-) , or at least use the track funstion to help out.

Doing the NDB stuff is great and all but in IMC use all the tools you have.

Scott

 

[RobertGerace]

You will enjoy your FAA charts, Bob. (get the bound ones unless you want a IAP-snowstorm in your cockpit/on the ramp from time to time.)

ROTFL! I already had the snowstorm happen once...in IMC...with ceilings close to approach minimums!

I just bought the bound subscriptions. About $600 per year. $1,400 less than Jepp. Sigh.

on NDB's...Bill S...thanks. I was hoping they would all go away. If I were Bill J...I would find a plane for my checkride that didn't have an ADF!!!!!

 

[wsuffa]

on NDB's...Bill S...thanks. I was hoping they would all go away.

I've got an ADF i'll sell you...

No really, it doesn't look like a bridge. Nor swampland.

 

[Bill]

If I were Bill J...I would find a plane for my checkride that didn't have an ADF!!!!!

Sorry, at least for the IR ride, I'll be in the plane with ADF. I must be weird, but I'm actually starting to LIKE NDB approaches.

Bill

 

[jdwatson]

Sorry, at least for the IR ride, I'll be in the plane with ADF. I must be weird, but I'm actually starting to LIKE NDB approaches.

Bill

You're weird. :-D