NDB Approach question

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Walboy

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Assuming you're not receiving vectors, the beacon is your IAF, after intercept you make a left turn on course for the procedure turn and fly the approach from there.
 
Walboy said:
I would fly my own non published course reversal to the southeast of the NDB while maintaining 5000. Once I re-cross the NDB on a published segment I could descend and fly the published procedure turn.
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If you make your course reversal close enough to the NDB, I can't think of a problem with that method. You're supposed to turn outbound on the procedure turn when you cross the NDB, but I don't think it has to be a standard-rate turn the whole way around.
 
Walboy said:
I would fly my own non published course reversal to the southeast of the NDB while maintaining 5000. Once I re-cross the NDB on a published segment I could descend and fly the published procedure turn.
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What’s wrong with telling ATC what you plan to do? ...and what’s wrong with planning a straight in approach? There are a couple hints on the plate.
 
labbadabba said:
Assuming you're not receiving vectors, the beacon is your IAF, after intercept you make a left turn on course for the procedure turn and fly the approach from there.
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Agree. You are cleared direct to the NDB and to maintain 5000'. After flying to the NDB TL intercept the PT outbound, descend to 2800', turn around, and shoot the approach.
 
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My #1 rule of instrument flying - don't be creative.

There are no published NoPT segments. Therefore, approaching from any direction, you are required to execute the procedure turn. So, cross the NDB and immediately turn the shortest direction to get heading outbound on the 305 bearing.
 
RussR said:
My #1 rule of instrument flying - don't be creative.

There are no published NoPT segments. Therefore, approaching from any direction, you are required to execute the procedure turn. So, cross the NDB and immediately turn the shortest direction to get heading outbound on the 305 bearing.
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HILPT makes more sense coming from the northwest as stated in the OP. Need to tell ATC what you are going to do.
 
Since you're not receiving vectors, the default procedure is a full approach. In this example you would need to perform a procedure turn. The procedure turn "barb" is on the right side of the final approach course, but since a specific type of course reveral is not depicted, you can perform whichever type you want as long as it is performed on the protected side. Personally, I would fly to the NDB, make a left turn to the outbound heading (305), fly outbound for 2-3 minutes performing a racetrack reversal, then turn inbound back towards the NDB descend the 1060' to the MDA. NDB needle flips and no airport in sight, execute the missed, climb out and turn back to the NDB to hold.
 
Walboy said:
Thanks for this. I had not considered not recrossing the NDB going outbound. I think you're suggesting to descend somewhat off but parallel to the published segment to 2800.

My thought is that you MUST be on a published segment before beginning a descent.
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Yes once you've turned around to intercept the PT outbound and established you'd begin your descent.
 
Walboy said:
I know I should have the definitive answer to this question...but I'm not 100% sure. Link to KCAV NDB RWY 14 approach is below.

http://airnav.com/depart?http://155.178.201.160/d-tpp/1802/06369N14.PDF

Let's say you're 20 miles northwest of Clarion, IA (KCAV) and receive this clearance:

"N12345, fly direct clarion NDB, maintain 5000, cleared for the NDB RWY 14 approach"

What does ATC expect me to do when I first reach the NDB?

I know what I would do, but I'm not sure it's proper.
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Report it. Then after that they would be expecting you to either cancel or report executing the Missed Approach. As far as how you are going to maneuver while doing the Procedure Turn, they'll be expecting you to do it on the side depicted on the Chart, the 'barb' on Gov charts and stay within 10 miles. I'd just use a racetrack pattern. Nice and easy on this one because there is a picture of one as the Missed Approach Fix. AIM 5-4-9 1.

1. On U.S. Government charts, a barbed arrow
indicates the maneuvering side of the outbound
course on which the procedure turn is made.
Headings are provided for course reversal using the
45 degree type procedure turn. However, the point at
which the turn may be commenced and the type and
rate of turn is left to the discretion of the pilot (limited
by the charted remain within xx NM distance). Some
of the options are the 45 degree procedure turn, the
racetrack pattern, the teardrop procedure turn, or the
80 degree 260 degree course reversal. Racetrack
entries should be conducted on the maneuvering side
where the majority of protected airspace resides. If an
entry places the pilot on the non−maneuvering side of
the PT, correction to intercept the outbound course
ensures remaining within protected airspace. Some
procedure turns are specified by procedural track.
These turns must be flown exactly as depicted
 
Walboy said:
Thanks for this. I had not considered not recrossing the NDB going outbound. I think you're suggesting to descend somewhat off but parallel to the published segment to 2800.

My thought is that you MUST be on a published segment before beginning a descent.
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The Procedure Turn is a published segement. It does cover a lot of geography and you can be a ways off of the pretty bold black line while flying it, but a published segement nonetheless
 
luvflyin said:
The Procedure Turn is a published segement. It does cover a lot of geography and you can be a ways off of the pretty bold black line while flying it, but a published segement nonetheless
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The problem was that he was coming from the Northwest as mentioned in the OP, which means about a 180-degree turn to get onto the outbound course for the procedure turn. Based on a formula I found by googling, the radius of a standard-rate turn at 90 knots should be about a half mile, so you'd be a mile away from the NDB when you reach the outbound course if you start a standard-rate 180-degree turn when you cross it.
 
iamtheari said:
The problem was that he was coming from the Northwest as mentioned in the OP, which means about a 180-degree turn to get onto the outbound course for the procedure turn. Based on a formula I found by googling, the radius of a standard-rate turn at 90 knots should be about a half mile, so you'd be a mile away from the NDB when you reach the outbound course if you start a standard-rate 180-degree turn when you cross it.
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The published hold at the NDB solves that little problem which is one reason the HILPT is a good solution. If there are concerns with descent rate either ask for lower on the way to the NDB or ask for an extra trip around the hold. MSA within 25 miles is what? 2,800 ft? No worries using the plotted hold.
 
The real question is landing on a 3,400ft runway, 1,100 feet in the air. Isn't that just a little bit reckless? I mean, I don't want to judge...
 
Clark1961 said:
The published hold at the NDB solves that little problem which is one reason the HILPT is a good solution. If there are concerns with descent rate either ask for lower on the way to the NDB or ask for an extra trip around the hold. MSA within 25 miles is what? 2,800 ft? No worries using the plotted hold.
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Yeah. I wouldn't be using the term HILPT to describe it though. It is not an HILPT. Yeah, an HILPT is a 'racetrack' pattern. This is not 'In Lieu' of a Procedure Turn. What were talking is entering into a racetrack pattern as a method of doing the Procedure Turn. You could do this if there was no holding pattern depicted there. The Missed Approach hold being there does give you a nice 'picture' of it.
 
iamtheari said:
The problem was that he was coming from the Northwest as mentioned in the OP, which means about a 180-degree turn to get onto the outbound course for the procedure turn. Based on a formula I found by googling, the radius of a standard-rate turn at 90 knots should be about a half mile, so you'd be a mile away from the NDB when you reach the outbound course if you start a standard-rate 180-degree turn when you cross it.
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Yeah. Hitting the NDB, reversing course and getting established on the 305 Bearing From CAV, and then doing the 45 degree thing, or the 80/260 thing or some other thing you cook up to get established on the 125 Course To CAV works. Lottsa turns. Just seems like 'busy work' to me. I'd do the racetrack thing. Two turns.
 
luvflyin said:
Yeah. I wouldn't be using the term HILPT to describe it though. It is not an HILPT. Yeah, an HILPT is a 'racetrack' pattern. This is not 'In Lieu' of a Procedure Turn. What were talking is entering into a racetrack pattern as a method of doing the Procedure Turn. You could do this if there was no holding pattern depicted there. The Missed Approach hold being there does give you a nice 'picture' of it.
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You can do what you want for the course reversal. I would use HILPT and avoid your course reversal problems. Of course there are challenges for the HILPT on a windy day. NDBs can be fun. Okay, not really but they aren’t that hard unless ya go out of your way to make them difficult (or you’re outside the US without enough ADFs).
 
luvflyin said:
Yeah. Hitting the NDB, reversing course and getting established on the 305 Bearing From CAV, and then doing the 45 degree thing, or the 80/260 thing or some other thing you cook up to get established on the 125 Course To CAV works. Lottsa turns. Just seems like 'busy work' to me. I'd do the racetrack thing. Two turns.
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I’ve done them as the 45 degree thing and as HILPT. HILPT wins. Saves a lot of time.
 
Clark1961 said:
You can do what you want for the course reversal. I would use HILPT and avoid your course reversal problems. Of course there are challenges for the HILPT on a windy day. NDBs can be fun. Okay, not really but they aren’t that hard unless ya go out of your way to make them difficult (or you’re outside the US without enough ADFs).
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Yeah. You have chosen to do a holding pattern instead(in lieu) of the 'barb' thing. But you are not doing it 'In Lieu' of a procedure turn. It "is" your procedure turn. Perfectly legal. I still think the term HILPT shouldn't be used in a discussion like this because HILPT is a distinct Term.
 
luvflyin said:
Yeah. You have chosen to do a holding pattern instead(in lieu) of the 'barb' thing. But you are not doing it 'In Lieu' of a procedure turn. It "is" your procedure turn. Perfectly legal. I still think the term HILPT shouldn't be used in a discussion like this because HILPT is a distinct Term.
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Why do you think I would not be doing a hold?
 
This is how I would have done it back before GPS and when I did ADF approaches all the time.

Fly to the NDB and do one turn in the holding pattern to get down to 2800. You have to stay within 10NM of the NDB. When you turn outbound start your timer when you are abeam the NDB and intercept the 305 radial. Fly outbound for 1 to 1:30 minutes, depending on speed. Do the procedure turn and when you intercept the 305 radial inbound descend to 1740. Hold that until you see the airport and land or pass the NDB and go missed. Remember the 1740 is also the circling minimums so if you see the airport too late just circle.
 
RussR said:
My #1 rule of instrument flying - don't be creative.

There are no published NoPT segments. Therefore, approaching from any direction, you are required to execute the procedure turn. So, cross the NDB and immediately turn the shortest direction to get heading outbound on the 305 bearing.
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As you know, that's an on-airport NDB, no FAF.

Alas, few understand the principles these days.
 
RussR said:
My #1 rule of instrument flying - don't be creative.

There are no published NoPT segments. Therefore, approaching from any direction, you are required to execute the procedure turn. So, cross the NDB and immediately turn the shortest direction to get heading outbound on the 305 bearing.
Click to expand...

I had to fly an on-airport NDB approach on my instrument checkride That is exactly the way I flew it and the DPE seemed to be happy.
 
somorris said:
I had to fly an on-airport NDB approach on my instrument checkride That is exactly the way I flew it and the DPE seemed to be happy.
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I had an NDB on my checkride and the DPE was happy with HILPT.
 
Clark1961 said:
You can do what you want for the course reversal. I would use HILPT and avoid your course reversal problems.
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Of course, remember that you can't descend from 2800 until you're established on the final approach course, so you would need to plan your outbound (and therefore inbound) leg length based around this. If you were to use a standard 1 minute holding pattern, once inbound you would have one minute to descend from 2800 feet to the runway at 1155 feet, requiring a descend rate of 1645 feet per minute, a bit excessive in most of the airplanes we're flying.

This type of consideration would also be applicable flying the "standard" PT as well. I might go out 2.5 - 3 minutes on this one, depending on wind, and of course if I can reasonably ensure I'll stay within 10 nm.
 
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Walboy said:
For those advocating a HILPT, I want to make sure I understand exactly what you're saying. IF I understand, this would equivalent to superimposing a left hand holding pattern on the 125 bearing to the station (305 bearing from), direct entry. Once the NDB is crossed and you're turned outbound on a heading of 305, you would then begin a descent to 2800 even though you're not exactly on a published segment? Once on the published bearing to the NDB, then descent to MDA?

I guess I am all wrapped up on the regulation to be on a published segment before beginning the descent.

One thing I have found interesting in this discussion is the absence of one "by the book" maneuver. So, it would seem I'm not the only one who has wondered about this.

I have no idea what the MVAs are in this area and what would happen in real world. I just randomly picked an airport in NDB land.

Thanks everyone for chiming in.
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As Russ pointed out and already discussed ATC would have to approve a descent prior to being established on the inbound course. In practice for approaches in the boonies there usually isn’t a problem getting approval either several miles out or when crossing the holding fix. On the selected approach the MSA lets the pilot know obstacles aren’t a problem so if traffic isn’t a problem ATC should approve an early descent request. A position report may be requested.

OTOH, if radar is available then ask for a vector and avoid the course reversal problem. From a practice perspective plan to fly the approach from an airway rather than rnav. I know we have more tools and can almost always avoid an NDB approach but there are some lessons to be learned in trying to find a damn beacon in the middle of nowhere.
 
Walboy said:
For those advocating a HILPT, I want to make sure I understand exactly what you're saying. IF I understand, this would equivalent to superimposing a left hand holding pattern on the 125 bearing to the station (305 bearing from), direct entry. Once the NDB is crossed and you're turned outbound on a heading of 305, you would then begin a descent to 2800 even though you're not exactly on a published segment? Once on the published bearing to the NDB, then descent to MDA?

I guess I am all wrapped up on the regulation to be on a published segment before beginning the descent.

One thing I have found interesting in this discussion is the absence of one "by the book" maneuver. So, it would seem I'm not the only one who has wondered about this.

I have no idea what the MVAs are in this area and what would happen in real world. I just randomly picked an airport in NDB land.

Thanks everyone for chiming in.
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You ARE on a published segment. It starts at CAV. Yeah, it's a little different than the usual 'straight line' segment where you're either right on, a little left or a little right. How you navigate while on this segment has a lot of flexibilty. The only 'hard' requirements are you remain within 10 miles of CAV and do your maneuvering on the side of the course depicted on the chart, in this case, the Northeast side. If you were arriving at CAV from say, the Southeast you might say 'I wanna keep this simple and make one turn back to final.' You could then depart CAV heading about 330 or so, give or take, depending on the winds and the anticipated radius of turn based on your ground speed, then make about a 210 degree or so turn back to final. Just don't go out farther than 10 miles and don't get below 2800 until you're inbound. Doing a direct entry into a racetrack pattern if you were arriving at CAV from a generally out west direction could be a lot easier than trying to fly the Bold Black Line. You could hit CAV, reverse course to the left, then a right turn to establish on the 305 Bearing From CAV, then a right turn to 350, then a left turn to 170, then another left turn to establish on the 125 Course To CAV. Or you could turn left to around 305, give or take depending on winds, fly outbound paralleling the approach course for long enough that you can have a comfortable turn back to final but not so long you bust the 10 mile limit and then turn left to join final inbound. It's kinda like an hilpt. But don't let yourself get caught thinking about the 1 minute legs of a {quote}HILPT{unquote}. That could make for pretty dang steep approach.[/quote]
 
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Walboy said:
If this is directed at me, that's why I'm asking questions. I know I have some gaps in my knowlege.
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No. You are asking the right questions. I was speaking of today's pilot population in general. That's why I sent my response to Russ. He works with these criteria. There is an additional layer of understanding that is required when using an NDB procedure like this from the RNAV database, such as understanding the sensor FAF.
 
Good question/discussion. I don't have my IFR but went through the ground school and it's been a long time since I looked at an NDB approach. Funny thing is this airport is about a 10 minute flight from my house. :)
 
If your NW of beacon and given clearance, fly direct to beacon then left turn 290 degrees and fly straight (5 T’s) until tail of indicator points 305 then right turn go outbound course 305 and descend 2800. Do PT then back to beacon on 125 degree until crossing beacon and execute missed if not in sight. Its been years since my rating but thats my best guess/recollection
 
I would maintain 5000, crossing the NDB I would turn right to a heading of 345 and slow to 100 KIAS, time out bound 2:00 upon crossing the 305 degree bearing from the station and start descent to 2800 ft. Then a left turn to 170, intercept and descend to MDA.
 
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Clip4 said:
I would maintain 5000, crossing the NDB I would turn right to a heading of 345 and slow to 100 KIAS, time out bound 2:00 upon crossing the 305 degree bearing from the station and start descent to 2800 ft. Then a left turn to 170, intercept and descend to MDA.
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Just to be clear, the descent to 2,800 can be commenced overhead the NDB as soon as the outbound turn is started. The procedure turn area has an entry zone and a maneuvering zone. The altitude for both is 2,800 in this case. When there is an obstacle in the entry zone that requires a higher altitude until within the maneuvering zone, that entry altitude restriction will be charted in the profile view above the NDB.
PT Area.jpg
 
aterpster said:
Just to be clear, the descent to 2,800 can be commenced overhead the NDB as soon as the outbound turn is started. The procedure turn area has an entry zone and a maneuvering zone. The altitude for both is 2,800 in this case. When there is an obstacle in the entry zone that requires a higher altitude until within the maneuvering zone, that entry altitude restriction will be charted in the profile view above the NDB.
View attachment 60418
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I think it's important to understand what that protected airspace generally looks like...I've had a couple of jet instructors over the years who thought there was no protected airspace on the "unprotected" side. They considered a parallel entry to be inherently dangerous (I consider them to be inherently too much work ;) ).
 
MauleSkinner said:
I think it's important to understand what that protected airspace generally looks like...I've had a couple of jet instructors over the years who thought there was no protected airspace on the "unprotected" side. They considered a parallel entry to be inherently dangerous (I consider them to be inherently too much work ;) ).
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This is different than the protected airspace for a HILPT.
 
aterpster said:
This is different than the protected airspace for a HILPT.
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They have a lot of space on the other side. FIG 5-3-7 of the AIM has a pretty good picture of it even though it's about slant range correction. The picture of the pattern itself is accurate. Like the PT, there's almost as much space on the 'non holding' side as the holding side.
 
luvflyin said:
They have a lot of space on the other side. FIG 5-3-7 of the AIM has a pretty good picture of it even though it's about slant range correction. The picture of the pattern itself is accurate. Like the PT, there's almost as much space on the 'non holding' side as the holding side.
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True enough. Having said that there are only three templates for the 10 miles procedure turn, depending on altitude. For the HILPT there are 10 templates, depending on altitude.

For the conventional procedure turn, there can sometimes be entry maximum altitude (ALW example) and in some cases an entry zone altitude restriction (JAC example):

KALW ILS.jpg KJAC ILS Y.jpg
 
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