NWADC9
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NDB-on-field App With Vectors - When To Descend?

Thu Nov 18, 2010 1:59 am

I was flying an NDB approach at an airport with the NDB on the field with radar vectors during VFR for practice. The full approach has you cross over the NDB, head outbound at a 045 heading, do a procedure turn, and descend to 2000 MSL (the MDA). However, with radar vectors, we were already lined up with the runway at 3000 MSL. Would I have to fly to the NDB, do a 180, the procedure turn, get lined up with the runway again, and then descend, or could I start descending when cleared for the approach? ATC only said, "Cleared for the practice approach." My instructor had me descend since that region is relatively flat, and it was VFR out, but had it been IFR in actual, what would be the proper way to do it?

Here's the plate:
http://aeronav.faa.gov/d-tpp/1011/05842N23.PDF
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akiss20
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RE: NDB-on-field App With Vectors - When To Descend?

Thu Nov 18, 2010 2:55 am

If you are given radar vectors to an approach segment, are established on the segment, and are "cleared for the approach" you may descend to the minimum altitude of that segment and continue descending as per the published approach.

In this case it sounds like you were simply given radar vectors to the final approach course. Once cleared for the approach and positive course guidance had been attained, you would be authorized to descend to the MDA. If in doubt, ask ATC.
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LimaFoxTango
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RE: NDB-on-field App With Vectors - When To Descend?

Thu Nov 18, 2010 2:55 am

I assume you were vectored to intercept the final approach coarse. As long as you're established on the inbound track 225*, you are allowed to leave 3000' to 2000' once cleared for the approach by ATC. No difference from being vectored for any other approach I'd say, whether VOR or ILS.
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IAHFLYR
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RE: NDB-on-field App With Vectors - When To Descend?

Thu Nov 18, 2010 3:16 am

Quoting NWADC9 (Thread starter):
Would I have to fly to the NDB, do a 180, the procedure turn, get lined up with the runway again, and then descend, or could I start descending when cleared for the approach?

Since there are no step down fixes the approach, the approach would appear to have no obstacles identifed and you're legal to descend right down to the MDA when given vectors to intercept the final.

Quoting NWADC9 (Thread starter):
Would I have to fly to the NDB, do a 180, the procedure turn

In almost every case, if you're lined up within 30 degrees of the inbound heading the controller expects you to fly straight in without making the PT. If you are the least bit unsure, ASK!!!

Quoting AKiss20 (Reply 1):
In this case it sounds like you were simply given radar vectors to the final approach course. Once cleared for the approach and positive course guidance had been attained, you would be authorized to descend to the MDA. If in doubt, ask ATC.

  
Any views shared are strictly my own and do not a represent those of any former employer.
 
Mir
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RE: NDB-on-field App With Vectors - When To Descend?

Thu Nov 18, 2010 3:45 am

The regs and AIM say that you must fly the procedure turn (and thus must do the full approach from the IAF) unless you are getting vectors to final or are cleared for a straight-in approach. Thus, unless the controller specifies that there will be vectors to final or clears you for the straight-in approach, you have to do the full procedure.

With that said, there have been times where the controller obviously was not planning on me doing a procedure turn, but also wasn't saying either of those things. In those cases, I asked for clarification (something like "confirm I'm cleared for the straight-in approach?"). And that's what I'd recommend you do if you're unsure. The phraseology gets somewhat technical here, and let's face the fact: that US pilots and controllers tend to be pretty lax about phraseology. So if in doubt, ask. I don't think that some controllers really understand the rules that the pilots are supposed to abide by with regard to procedure turns and full approaches. AIM 5-4-9 provides some guidance here, and IMO the most important part of it is the last sentence of the note after 5-4-9-a.

Quoting LimaFoxTango (Reply 2):
As long as you're established on the inbound track 225*, you are allowed to leave 3000' to 2000' once cleared for the approach by ATC.

And as long as you're within 10 miles of the NDB.

Quoting IAHFLYR (Reply 3):
In almost every case, if you're lined up within 30 degrees of the inbound heading the controller expects you to fly straight in without making the PT.

But that's not what the regs and AIM say. I can be on the final approach course, but if you didn't vector me there or clear me for a straight-in approach, I am legally obligated to do the full procedure with PT.

-Mir
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DashTrash
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RE: NDB-on-field App With Vectors - When To Descend?

Thu Nov 18, 2010 3:51 am

Keep it simple...

Remain at your assigned altitude until established on a published segment of the approach.
 
flight152
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RE: NDB-on-field App With Vectors - When To Descend?

Thu Nov 18, 2010 4:09 am

Quoting DashTrash (Reply 5):
Remain at your assigned altitude until established on a published segment of the approach.


That's a pretty generic statement, with no final approach fix (because the navaid is on the field) there is no defined place to start a descent.
 
sccutler
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RE: NDB-on-field App With Vectors - When To Descend?

Thu Nov 18, 2010 4:40 am

I do not believe there is any basis for vectors to final for an NDB approach; I guess you can play any game you choose when practicing under the hood with a safety pilot, but I'd never, but never, accept a clearance for an NDB approach like this, except for the full procedure (not that I ever expect to have that offered in actual).

So my answer to the original question would be, "...I'd descend procedure turn inbound, after starting the approach at the IAF (CASTLE NDB)."
...three miles from BRONS, clear for the ILS one five approach...
 
Fly2HMO
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RE: NDB-on-field App With Vectors - When To Descend?

Thu Nov 18, 2010 4:51 am

Quoting AKiss20 (Reply 1):
If in doubt, ask ATC.
Quoting IAHFLYR (Reply 3):
If you are the least bit unsure, ASK!!!
Quoting Mir (Reply 4):
So if in doubt, ask.

Good to see people stressing this EXTREMELY important point. Many students take this for granted, and many CFIs overlook this.

Quoting Flight152 (Reply 6):


That's a pretty generic statement, with no final approach fix (because the navaid is on the field) there is no defined place to start a descent.

Not necessarily. In a case like OP's that "place" would be the point where ATC clears him for the approach.


Here's a trick question: say you're flying an old Mooney with a busted DME, no GPS. How do you know you're within 10nm from the NDB if you're giving vectors to final?

[Edited 2010-11-17 20:52:20]
 
Mir
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RE: NDB-on-field App With Vectors - When To Descend?

Thu Nov 18, 2010 4:57 am

Quoting Fly2HMO (Reply 8):
Here's a trick question: say you're flying an old Mooney with a busted DME, no GPS. How do you know you're within 10nm from the NDB?

You don't. So unless ATC can provide that information, I'm going to the NDB and flying the full procedure. Granted, there's no absolute guarantee you'd stay within 10nm that way either, but if you fly the approach profile correctly, you should be okay - far more reliable than trying to guess when you're within 10nm on the straight-in.

-Mir
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sccutler
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RE: NDB-on-field App With Vectors - When To Descend?

Thu Nov 18, 2010 5:15 am

Quoting Mir (Reply 9):
You don't. So unless ATC can provide that information, I'm going to the NDB and flying the full procedure. Granted, there's no absolute guarantee you'd stay within 10nm that way either, but if you fly the approach profile correctly, you should be okay - far more reliable than trying to guess when you're within 10nm on the straight-in.

We have a winner.

Remember, the axiomatic rules of aviation mistakes:

Pilot screws up, pilot dies.

Controller screws up, pilot dies.

I am aware of no reliable means to ensure you're on a protected approach segment, on an NDB approach like this one, without flying the full procedure.
...three miles from BRONS, clear for the ILS one five approach...
 
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akiss20
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RE: NDB-on-field App With Vectors - When To Descend?

Thu Nov 18, 2010 5:29 am

Quoting SCCutler (Reply 10):
I am aware of no reliable means to ensure you're on a protected approach segment, on an NDB approach like this one, without flying the full procedure.

I stand corrected, only making it more obvious how quickly IFR skills can deteriorate (it has been 3 months since I have flown due to going back to school in Cambridge, MA).

SCCutler and others are right in saying there is no definitive way to determine whether you are on the published (10nm) final approach path and thus safe to descend to MDA.

Are NDB approach MDAs typically lower than the controller's MVA for the sector containing the final approach path? I am very unsure of this, my gut says absolutely, but if they were not I would not see the difference between accepting the descent on final from the controller and accepting say a descent to glideslope intersection altitude while on the 45 for an ILS.
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jgarrido
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RE: NDB-on-field App With Vectors - When To Descend?

Thu Nov 18, 2010 6:32 am

Quoting NWADC9 (Thread starter):

Had you been IFR I'm sure the phraseology probably been something like:

"XX miles from the FAF. Fly heading XXX, maintain 3000 until established on the final approach course cleared NDB approach". The idea being that the controller is responsible for your obstruction clearance by keeping you at or above the MVA/MIA until you are established on final at which point you can descend as depicted on the approach. Then you are safe because the approach has been TERPS out to provide obstruction clearance. Being VFR the controller gave you fewer requirements so you could "do your own thing".


Quoting AKiss20 (Reply 11):
Are NDB approach MDAs typically lower than the controller's MVA for the sector containing the final approach path?

I can't say with 100% certainty but I would think yes. MVA's are drawn up for relatively large areas compared to the MDA of an approach only has to cover the area of the approach course.
 
KELPkid
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RE: NDB-on-field App With Vectors - When To Descend?

Thu Nov 18, 2010 6:50 am

Quoting AKiss20 (Reply 1):
Once cleared for the approach and positive course guidance had been attained, you would be authorized to descend to the MDA

   Once you are established on the final approach course, you can descend to the MDA...that means within +/- 5 degrees of the approach course, IIRC (been too long since I shot an archaic instrument approach   )..
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KELPkid
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RE: NDB-on-field App With Vectors - When To Descend?

Thu Nov 18, 2010 6:54 am

Quoting Mir (Reply 9):
Here's a trick question: say you're flying an old Mooney with a busted DME, no GPS. How do you know you're within 10nm from the NDB?

You don't. So unless ATC can provide that information, I'm going to the NDB and flying the full procedure. Granted, there's no absolute guarantee you'd stay within 10nm that way either, but if you fly the approach profile correctly, you should be okay - far more reliable than trying to guess when you're within 10nm on the straight-in.

(Assuming you're not cheating and looking at your non-IFR approved GPS attached to the yoke...)   Not "legal" to use for primary navigation in this instance, but it sure does wonders for situational awareness while IFR...  
Celebrating the birth of KELPkidJR on August 5, 2009 :-)
 
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akiss20
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RE: NDB-on-field App With Vectors - When To Descend?

Thu Nov 18, 2010 7:00 am

Quoting KELPkid (Reply 13):
Quoting AKiss20 (Reply 1):
Once cleared for the approach and positive course guidance had been attained, you would be authorized to descend to the MDA

Once you are established on the final approach course, you can descend to the MDA...that means within +/- 5 degrees of the approach course, IIRC (been too long since I shot an archaic instrument approach )..

This is true in general, but as was pointed out prior there is no way of knowing if you are on the published final approach course (as opposed to the extended centerline of the runway. The former ends 10nm from the threshold while the latter extends indefinitely). Without knowing if you are on the legal final approach course, you cannot descend to MDA.

Quoting jgarrido (Reply 12):
Quoting AKiss20 (Reply 11):
Are NDB approach MDAs typically lower than the controller's MVA for the sector containing the final approach path?

I can't say with 100% certainty but I would think yes. MVA's are drawn up for relatively large areas compared to the MDA of an approach only has to cover the area of the approach course.

That is what I figured. I know MVA sectors tend to be pretty broad, but also know they can get oddly specific sometimes to handle certain transitions in approaches.
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Mir
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RE: NDB-on-field App With Vectors - When To Descend?

Thu Nov 18, 2010 7:01 am

Quoting AKiss20 (Reply 11):
Are NDB approach MDAs typically lower than the controller's MVA for the sector containing the final approach path?

I don't know about typically, but I'd say that unless you're doing one in a busy area with lots of radar coverage, you should expect that to be the case.

Quoting KELPkid (Reply 13):
Once you are established on the final approach course, you can descend to the MDA...

Again, only if you're inside the ring specified on the approach plate. You could pick up and track the NDB bearing 20nm out, but if you descended below 3000' at that point you'd be descending into a world where there be lurking demons of solidity/nastiness.

-Mir
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IAHFLYR
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RE: NDB-on-field App With Vectors - When To Descend?

Thu Nov 18, 2010 1:11 pm

Quoting Mir (Reply 4):
But that's not what the regs and AIM say. I can be on the final approach course, but if you didn't vector me there or clear me for a straight-in approach, I am legally obligated to do the full procedure with PT.

-Mir

A controller is required to tell you the reason for a vector, "fly heaing 310, vectors NDB Runway XX final approach course.

Quoting Fly2HMO (Reply 8):
Good to see people stressing this EXTREMELY important point. Many students take this for granted, and many CFIs overlook this.

A simple asking has kept me out of more than my share of problems.
Any views shared are strictly my own and do not a represent those of any former employer.
 
mandala499
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RE: NDB-on-field App With Vectors - When To Descend?

Thu Nov 18, 2010 2:17 pm

Quoting Mir (Reply 4):
And as long as you're within 10 miles of the NDB.

But then it's an NDB approach.

Quoting Flight152 (Reply 6):
That's a pretty generic statement, with no final approach fix (because the navaid is on the field) there is no defined place to start a descent.

Hmm... The Jepp plate has an FF23 at 6.1NM from the threshold...    You can do 2000 to FF23 then go down at 3degs... but then it's only if you know where FF23 is... got RNAV? Otherwise... ASK!

Quoting Fly2HMO (Reply 8):
Good to see people stressing this EXTREMELY important point. Many students take this for granted, and many CFIs overlook this.

Also controllers from time to time...

Quoting Fly2HMO (Reply 8):
Here's a trick question: say you're flying an old Mooney with a busted DME, no GPS. How do you know you're within 10nm from the NDB if you're giving vectors to final?

Ask!    If not... state intention... But I would thought that "practice approach" would "normally" mean the full damn procedure!

But then... am on the other side of the world so... I'd go along with the guys who I quoted!   

My -2 cents!
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Pihero
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RE: NDB-on-field App With Vectors - When To Descend?

Thu Nov 18, 2010 4:03 pm

Quoting Mir (Reply 4):
The regs and AIM say that you must fly the procedure turn (and thus must do the full approach from the IAF) unless you are getting vectors to final or are cleared for a straight-in approach.

     
An instrument approach is designed to help you determine a final path to the runway, in the absence of an ILs glide slope... or a distance measurement device.
It follows that in this case, that final slope is only defined by how much care you've devoted to your outbound leg timing, in the real world, you'll have to follow the whole procedure.
Had that approach had a marker or another beacon to define a descent path, you would have been legal to descend to your sector MSA and pass the marker/beacon at the published altitude, configured for final.
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Mir
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RE: NDB-on-field App With Vectors - When To Descend?

Thu Nov 18, 2010 4:17 pm

Quoting IAHFLYR (Reply 17):
A controller is required to tell you the reason for a vector, "fly heaing 310, vectors NDB Runway XX final approach course.

I know. But not all of them do.

-Mir
7 billion, one nation, imagination...it's a beautiful day
 
IAHFLYR
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RE: NDB-on-field App With Vectors - When To Descend?

Thu Nov 18, 2010 5:41 pm

Quoting Mir (Reply 20):
I know. But not all of them do.



Stop it, say it isn't so!!  
Quoting mandala499 (Reply 18):
But I would thought that "practice approach" would "normally" mean the full damn procedure!



Not always the case. When I request a practice approach in a RADAR environment I expect to get vectors to the final approach course or if an RNAV with a "T" or "L" design to get vectors the final approach course or cleared direct to an IAF or IF on the procedure. If I want to do the full procedure turn/racetrack pattern then I specifically request that with the controller.
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akiss20
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RE: NDB-on-field App With Vectors - When To Descend?

Thu Nov 18, 2010 6:20 pm

Quoting IAHFLYR (Reply 21):
Quoting Mir (Reply 20):
I know. But not all of them do.



Stop it, say it isn't so!!

So much so that in the modern day I would argue that the controller expects you NOT to do a full approach and would only alter the approach clearance if he wanted one. Doesn't follow FARs, AIM, or 7110.65 but it's the reality.

Quoting IAHFLYR (Reply 21):
Quoting mandala499 (Reply 18):
But I would thought that "practice approach" would "normally" mean the full damn procedure!



Not always the case. When I request a practice approach in a RADAR environment I expect to get vectors to the final approach course or if an RNAV with a "T" or "L" design to get vectors the final approach course or cleared direct to an IAF or IF on the procedure. If I want to do the full procedure turn/racetrack pattern then I specifically request that with the controller.

Absolutely true for the NYC area. Controllers will always give you vectors to final unless if you ask for something else. I have always had to request full procedure, procedure turn, published missed approach etc.

In fact controllers in the area get pretty nervous about giving full approaches without radar contact. My CFII told me once that they tried to refuse him a VOR approach into Sussex (KFWN) in actual because once you get passed the IAF you are descending into a valley where radar coverage is spotty. He apparently had to go missed and once he tuned back to NY App from UNICOM he heard them semi-frantically trying to raise him.
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KELPkid
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RE: NDB-on-field App With Vectors - When To Descend?

Thu Nov 18, 2010 6:49 pm

Quoting AKiss20 (Reply 15):
This is true in general, but as was pointed out prior there is no way of knowing if you are on the published final approach course (as opposed to the extended centerline of the runway. The former ends 10nm from the threshold while the latter extends indefinitely). Without knowing if you are on the legal final approach course, you cannot descend to MDA.

Please tell me your instructor/flight school didn't teach you how to tell what NDB bearing you're on?    It is possible, even in a plane equipped with nothing but an NDB receiver with a plane ADF jane bearing indicator and a DG. My instructor taught me to mentally superimpose the ADF needle on top of the DG. In my case, it worked like a charm. Of course, the problem in general with an NDB approach is that NDB navigation is just not real accurate (which is reflected in the higher minimums).

Quoting Mir (Reply 20):
Quoting IAHFLYR (Reply 17):
A controller is required to tell you the reason for a vector, "fly heaing 310, vectors NDB Runway XX final approach course.

I know. But not all of them do.

-Mir

In my experience, controllers aren't too bad about telling you "vectors to final" when shooting an approach. An approach clearance following vectors to final usually includes "descend when established on final approach course, cleared NDB Alpha at XXX", which means it is up to you to determine when you are established on the final approach course.
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Mir
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RE: NDB-on-field App With Vectors - When To Descend?

Thu Nov 18, 2010 6:54 pm

Quoting IAHFLYR (Reply 21):
Stop it, say it isn't so!!

But that's the issue - I may know that they're vectoring me to final, but unless they say it, technically they're not, and I have to do the full procedure.

Quoting AKiss20 (Reply 22):
So much so that in the modern day I would argue that the controller expects you NOT to do a full approach and would only alter the approach clearance if he wanted one. Doesn't follow FARs, AIM, or 7110.65 but it's the reality.

It is commonplace. Which raises the question: do you just "go with the flow", even though it's not what you're supposed to do? If something happens, the FAA could find you at fault, even if the controller guided you into doing something outside of the FARs or AIM. On the other hand, nobody likes to discuss technicalities with ATC over the air.

-Mir
7 billion, one nation, imagination...it's a beautiful day
 
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akiss20
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RE: NDB-on-field App With Vectors - When To Descend?

Thu Nov 18, 2010 6:58 pm

Quoting KELPkid (Reply 23):
Quoting AKiss20 (Reply 15):
This is true in general, but as was pointed out prior there is no way of knowing if you are on the published final approach course (as opposed to the extended centerline of the runway. The former ends 10nm from the threshold while the latter extends indefinitely). Without knowing if you are on the legal final approach course, you cannot descend to MDA.

Please tell me your instructor/flight school didn't teach you how to tell what NDB bearing you're on? It is possible, even in a plane equipped with nothing but an NDB receiver with a plane ADF jane bearing indicator and a DG. My instructor taught me to mentally superimpose the ADF needle on top of the DG. In my case, it worked like a charm. Of course, the problem in general with an NDB approach is that NDB navigation is just not real accurate (which is reflected in the higher minimums).

Did you even read what I wrote?  

Of course I know how to tell what NDB bearing I am on (I did all my IFR in a /A 172 with ADF, I was doing partial panel NDB holds....) but my point/the point of others is that while you can tell if you are on the bearing, you cannot tell from vectors to final if you are within 10NM of the threshold. The final approach segment is only valid to 10NM from the threshold, so while you may be on the proper bearing to the NDB, you have no way of knowing if you are within 10NM. You can only descend to MDA once on the published final approach segment, which as stated is the final approach bearing up until 10NM of the threshold, thus you would have no way of knowing when you are on the published final approach segment and thus when you could legally/safely descend.
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Mir
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RE: NDB-on-field App With Vectors - When To Descend?

Thu Nov 18, 2010 7:20 pm

Quoting KELPkid (Reply 23):
My instructor taught me to mentally superimpose the ADF needle on top of the DG.

Which is the way to go. MB + RB = Mental Math = Trouble.

Quoting AKiss20 (Reply 25):
Did you even read what I wrote?

I think the confusion came from the fact that you said:

Quoting AKiss20 (Reply 15):
there is no way of knowing if you are on the published final approach course

when you actually meant the final approach segment.

The final approach course extends out indefinitely (or at least as far as navaid coverage allows), but the final approach segment is just the portion of the final approach course that is published on the plate as being beyond the final approach fix. In this case, since there is no published FAF, the final approach segment begins when you are established inbound and are within the 10nm ring specified by the approach plate. Your concept was correct, but your terminology wasn't.

In your previous post, you compared the final approach course to the extended centerline, but this isn't always going to be correct, as unless the final approach course is exactly lined up with the runway, it and the runway centerline are two different things (and with an NDB or VOR approach, this is often the case).

-Mir
7 billion, one nation, imagination...it's a beautiful day
 
Fly2HMO
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RE: NDB-on-field App With Vectors - When To Descend?

Thu Nov 18, 2010 7:20 pm

Quoting Mir (Reply 9):

You don't. So unless ATC can provide that information, I'm going to the NDB and flying the full procedure.
Quoting SCCutler (Reply 10):
We have a winner.

Indeed.

Quoting mandala499 (Reply 18):

Ask!

What if you suddenly become mute? Your radio dies? The controller has a heart attack? Or...     
 
KELPkid
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RE: NDB-on-field App With Vectors - When To Descend?

Thu Nov 18, 2010 7:24 pm

Quoting AKiss20 (Reply 25):
Of course I know how to tell what NDB bearing I am on (I did all my IFR in a /A 172 with ADF, I was doing partial panel NDB holds....) but my point/the point of others is that while you can tell if you are on the bearing, you cannot tell from vectors to final if you are within 10NM of the threshold. The final approach segment is only valid to 10NM from the threshold, so while you may be on the proper bearing to the NDB, you have no way of knowing if you are within 10NM. You can only descend to MDA once on the published final approach segment, which as stated is the final approach bearing up until 10NM of the threshold, thus you would have no way of knowing when you are on the published final approach segment and thus when you could legally/safely descend.

If the controller has you down to 3000' while vectoring, (likely in this case), when you are given vectors to final, and told "descend when established on final approach course, Cleared NDB Runway 23 at Newcastle" this means that you are (in theory, and assuming the controller is watching out for you) inside the 10 NM limit for the approach. Of course, controllers are human, and do screw up from time to time (as do pilots   ). The only way to know for sure is to have a GPS on board with UCP punched in as the destination, in which case the GPS will show how far from the field you are. Of course, if the GPS is not IFR certified, it cannot be used for primary navigation, or even "officially" to determine how far you really are from the field, but only for situational awareness.

In all truth, though, I would not stake my life on this approach. It might be a great training aid to learn how to shoot an NDB approach, but, as you point out, it is hard to tell where you really are. Especially when you are own nav. You could time the station passage (which you have to do for the procedure turn outbound anyways), but that has its own limits, especially in nasty, windy weather.

In looking at the approach plate, I'm really suprised that there's no GPS overlay for this one.
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Fly2HMO
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RE: NDB-on-field App With Vectors - When To Descend?

Thu Nov 18, 2010 7:30 pm

Quoting KELPkid (Reply 28):
Cleared NDB Runway 23 at Newcastle" this means that you are (in theory, and assuming the controller is watching out for you) inside the 10 NM limit for the approach

Even if you're not inside 10NM, you should (again, in theory) be guaranteed obstacle clearance even if you were outside of 10NM once he clears you for the approach. I don't remember what the 7110.65 general clearance limits are but no controller will willingly clear you into a mountain, purposely, at least, you hope  cheeky 

Quoting KELPkid (Reply 28):
In looking at the approach plate, I'm really suprised that there's no GPS overlay for this one.

While it may not be published, any modern GPS *should* have an overlay for all approaches for a given airport in it's database. Of course most of them have the disclaimer "only to be used for situational awareness"  



[Edited 2010-11-18 11:36:16]
 
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akiss20
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RE: NDB-on-field App With Vectors - When To Descend?

Thu Nov 18, 2010 8:17 pm

Quoting Mir (Reply 26):
Quoting AKiss20 (Reply 15):
there is no way of knowing if you are on the published final approach course

when you actually meant the final approach segment.

You are correct, I used the wrong terminology initially, if you read my last response, I corrected myself. Should have made that correction clearer. Apologize for the confusion

Quoting KELPkid (Reply 28):
this means that you are (in theory, and assuming the controller is watching out for you) inside the 10 NM limit for the approach.

Source? What is to prevent a controller from having you join the final approach course 15nm out? I have been vectored for 15nm ILSes before. Controllers can and do vector you to the final approach COURSE instead of the final approach SEGMENT (see above discussion)

The difference with this approach and many others is that there are no stepdowns on the final approach course, thus there is no positive fix by which you can say "okay I am now at point X on the approach, I can now descend to the minimum altitude for the next segment of the approach because I have just entered that segment"


This is a good exercise to keep my IFR brain alive, so please anyone correct any of the above statements if I am in error
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IAHFLYR
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RE: NDB-on-field App With Vectors - When To Descend?

Thu Nov 18, 2010 8:30 pm

Quoting AKiss20 (Reply 22):
So much so that in the modern day I would argue that the controller expects you NOT to do a full approach and would only alter the approach clearance if he wanted one



I can guarantee you that a controller does not expect you to fly the full procedure when they've told you it is vectors to the final approach course.

Quoting AKiss20 (Reply 22):
Doesn't follow FARs, AIM, or 7110.65



Where in the .65 does this back up your statement?

Quoting Mir (Reply 24):
but unless they say it, technically they're not



As you know that is why it is a required transmission per the .76, paragraph5-6-2(b)! And no, that does not mean it always happens, again as you know.
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KELPkid
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RE: NDB-on-field App With Vectors - When To Descend?

Fri Nov 19, 2010 12:20 am

Quoting AKiss20 (Reply 30):
Source? What is to prevent a controller from having you join the final approach course 15nm out? I have been vectored for 15nm ILSes before. Controllers can and do vector you to the final approach COURSE instead of the final approach SEGMENT (see above discussion)

Look at the 7110.65, Subpart b of section 4.8.1  
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sccutler
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RE: NDB-on-field App With Vectors - When To Descend?

Fri Nov 19, 2010 6:41 am

Fascinating discussion, good fun.

I have seen NDB/DME approaches (none here in US that I am aware of, still some in Canada). Quick, how many of you are carrying the DME Channeling Tables in your flight bag?

---

Have also seen some of the 2 NDB approaches which are common in Russia and former USSR - two NDBs, one each off of each end of the runway on extended centerline. Fly with two ADFs, on a single RMI-like display. Needles line up, you're aligned with the runway. Simple, effective, no calibration. Sometimes the easy way is good!
...three miles from BRONS, clear for the ILS one five approach...
 
Mir
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RE: NDB-on-field App With Vectors - When To Descend?

Fri Nov 19, 2010 7:22 am

Quoting SCCutler (Reply 33):
Quick, how many of you are carrying the DME Channeling Tables in your flight bag?

IIRC, they're in the NACO approach plates, in the introduction or something like that.

-Mir
7 billion, one nation, imagination...it's a beautiful day
 
jgarrido
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RE: NDB-on-field App With Vectors - When To Descend?

Fri Nov 19, 2010 7:56 am

Quoting SCCutler (Reply 33):
I have seen NDB/DME approaches (none here in US that I am aware of, still some in Canada).

They're around.

Here on Guam. We only have ILS approaches to 6. For 24 the only approaches are RNAV's and an NDB-DME. NWA's old 757 that are now DAL now can't do GPS approaches (let alone RNP) so the 3 or 4 months each year when the winds change you can see an airliner shoot an NDB-DME approach. It goes right over an 800ft hill a couple miles from the threshold too so if the wx is bad it's kind of a scary thing.

DME+RWY+24R" target="_blank">http://flightaware.com/resources/airport/PGUM/IAP/NDB_DME+RWY+24R
 
Max Q
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RE: NDB-on-field App With Vectors - When To Descend?

Fri Nov 19, 2010 8:54 am

Quoting KELPkid (Reply 23):

Please tell me your instructor/flight school didn't teach you how to tell what NDB bearing you're on? It is possible, even in a plane equipped with nothing but an NDB receiver with a plane ADF jane bearing indicator and a DG. My instructor taught me to mentally superimpose the ADF needle on top of the DG. In my case, it worked like a charm. Of course, the problem in general with an NDB approach is that NDB navigation is just not real accurate (which is reflected in the higher minimums).

Good technique.

Quoting Fly2HMO (Reply 8):


Here's a trick question: say you're flying an old Mooney with a busted DME, no GPS. How do you know you're within 10nm from the NDB if you're giving vectors to final?

No trick there, that is what timing is for.
The best contribution to safety is a competent Pilot.
 
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RE: NDB-on-field App With Vectors - When To Descend?

Fri Nov 19, 2010 6:44 pm

Quoting Max Q (Reply 36):
No trick there, that is what timing is for.

The only way that works is if you're doing the full procedure, noticed I said "if you're given vectors to final"
 
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RE: NDB-on-field App With Vectors - When To Descend?

Fri Nov 19, 2010 11:30 pm

Quoting Fly2HMO (Reply 37):

The only way that works is if you're doing the full procedure, noticed I said "if you're given vectors to final

If the controller won't tell you you can use cross radials to fix your position. I used to do it all the time flying single pilot freight.
The best contribution to safety is a competent Pilot.
 
Fly2HMO
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RE: NDB-on-field App With Vectors - When To Descend?

Sat Nov 20, 2010 2:47 am

Quoting Max Q (Reply 38):
If the controller won't tell you you can use cross radials to fix your position. I used to do it all the time flying single pilot freight.

Well of course, but I was referring to OP's posted approach specifically. Of course you can use cross radials and all that other stuff, but this plate has none of that published. There are no cross radials or other fixes published and adequately positioned that could easily aid in determining distance TO the station when given vectors to final. Remember, we were assuming very basic IFR equipment, no GPS, inop DME.

If you know any obscure method to find the distance to the station when given vectors to final, without asking ATC, given the equipment I mentioned, I'm all ears.
 
mandala499
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RE: NDB-on-field App With Vectors - When To Descend?

Sat Nov 20, 2010 5:35 am

Quoting Fly2HMO (Reply 39):
There are no cross radials or other fixes published and adequately positioned that could easily aid in determining distance TO the station when given vectors to final. Remember, we were assuming very basic IFR equipment, no GPS, inop DME.

Basic IFR? at least 1 OBS and 1 ADF and inop DME?
If you're using Jepp charts... it'll show that VOLAN is R-275/31.3 CIP... you can "cheat" by staying on or north of R-275 CIP @3000 and only descend when on tracking inbound the Final Course and south of R-275 CIP.

By doing that... you will intercept the final course before FF23 (@6.1NM from threshold).. and R-045 UCP/R-275 CIP is before the FF23 but within 10NM from the NDB.

Legal or not? I dunno... but where I am... the regulators don't care much about these things... if you get called by the FAA for doing the above then don't blame me either.    ... BUT... If based on the chart given... then... the "cheat" info isn't available (hence don't do it). But I guess the above "cheat" goes along the same methodology as:

Quoting Max Q (Reply 38):
If the controller won't tell you you can use cross radials to fix your position. I used to do it all the time flying single pilot freight.

Just me 100 Indonesian Rupiah...   
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Max Q
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RE: NDB-on-field App With Vectors - When To Descend?

Sat Nov 20, 2010 5:43 am

Quoting Fly2HMO (Reply 39):

Well of course, but I was referring to OP's posted approach specifically. Of course you can use cross radials and all that other stuff, but this plate has none of that published. There are no cross radials or other fixes published and adequately positioned that could easily aid in determining distance TO the station when given vectors to final. Remember, we were assuming very basic IFR equipment, no GPS, inop DME.

If you know any obscure method to find the distance to the station when given vectors to final, without asking ATC, given the equipment I mentioned, I'm all ears.

Without the benefit of other radio aids to fix your position and / or ATC distance updates I would insist on flying the full procedure. That would allow me to start timing with station passage overhead Castle outbound for the procedure turn.
The best contribution to safety is a competent Pilot.
 
Fly2HMO
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RE: NDB-on-field App With Vectors - When To Descend?

Sat Nov 20, 2010 7:00 am

Quoting mandala499 (Reply 40):

Basic IFR? at least 1 OBS and 1 ADF and inop DME?
If you're using Jepp charts... it'll show that VOLAN is R-275/31.3 CIP... you can "cheat" by staying on or north of R-275 CIP @3000 and only descend when on tracking inbound the Final Course and south of R-275 CIP.

By doing that... you will intercept the final course before FF23 (@6.1NM from threshold).. and R-045 UCP/R-275 CIP is before the FF23 but within 10NM from the NDB.

Good, very good.

Quoting mandala499 (Reply 40):
. BUT... If based on the chart given... then... the "cheat" info isn't available (hence don't do it).

It's appalling how much info NACO charts lack compared to Jepps. Then again, they're cheap for a reason   

Quoting Max Q (Reply 41):

Without the benefit of other radio aids to fix your position and / or ATC distance updates I would insist on flying the full procedure. That would allow me to start timing with station passage overhead Castle outbound for the procedure turn.

Yup, only way around it with the NACO chart it seems.
 
Pihero
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RE: NDB-on-field App With Vectors - When To Descend?

Sat Nov 20, 2010 1:36 pm

Quoting Max Q (Reply 41):
Without the benefit of other radio aids to fix your position and / or ATC distance updates I would insist on flying the full procedure. That would allow me to start timing with station passage overhead Castle outbound for the procedure turn.

MaxQ,
That's what I wrote earlier but people seem to be fixated on mixing the unmixable : an NDB and vectors.

Quoting Pihero (Reply 19):
An instrument approach is designed to help you determine a final path to the runway, in the absence of an ILs glide slope... or a distance measurement device.
It follows that in this case, that final slope is only defined by how much care you've devoted to your outbound leg timing, in the real world, you'll have to follow the whole procedure.

Secondly, and the regs are quite strict on this :
If a fix/another aid/... isn't part of the officiallypublished approach p[late, you're not supposed to implement your let-down.
As far as the regulator - and the chief pilot - is concerned, the plate has been sealed in the bible.

Btw, I really don't see the point of just making an ADF final. Might as well go visual and pretend to follow the needle.
But, as MaxQ has very generously gently hinted, there's a lot more of training and discipline to an ADF approach than people really think.
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Mir
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RE: NDB-on-field App With Vectors - When To Descend?

Sat Nov 20, 2010 10:04 pm

Quoting Fly2HMO (Reply 42):
It's appalling how much info NACO charts lack compared to Jepps.

Examples? Granted, I'm not a big user of Jeppesen enroute charts, so I don't have a whole lot of expertise there, but IMO the Jepp and NACO approach plates are very similar in terms of information displayed.

-Mir
7 billion, one nation, imagination...it's a beautiful day
 
Fly2HMO
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RE: NDB-on-field App With Vectors - When To Descend?

Sun Nov 21, 2010 3:35 am

Quoting Mir (Reply 44):

Examples? Granted, I'm not a big user of Jeppesen enroute charts, so I don't have a whole lot of expertise there, but IMO the Jepp and NACO approach plates are very similar in terms of information displayed.

Jepps tend to be more intuitive IMO and have much more information. Let's compare OP's approach:

http://i53.tinypic.com/27z9rg4.png

The NACO chart is extremely plain. What I find extremely absurd with this particular NACO chart is that there are 3 fixes shown where you have no possible way to identify them in the chart itself (though they probably show up in the enroute chart), unless you have a GPS. Also, there's barely any obstacles listed, and it's missing another airport nearby and a city. The Jepp chart has much more detail and gives you cross radials to identify those fixes in the outskirts and GPS fixes. My only criticisms with Jepps is that some can get pretty cluttered, and they're expensive. I can find my way around with either chart no problem but I much rather use Jepps if I can.

[Edited 2010-11-20 19:36:04]

[Edited 2010-11-20 19:37:24]
 
sccutler
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RE: NDB-on-field App With Vectors - When To Descend?

Sun Nov 21, 2010 5:14 am

Quoting Fly2HMO (Reply 45):
. What I find extremely absurd with this particular NACO chart is that there are 3 fixes shown where you have no possible way to identify them in the chart itself (though they probably show up in the enroute chart), unless you have a GPS.

Excellent illustration.

I sure wish I could afford the amazing cost of Jepps.
...three miles from BRONS, clear for the ILS one five approach...

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