Understanding how to fly a holding pattern

[eetrojan]

My plotter shows that as about 027, not 015.

Ah. You're right. Here's a corrected diagram. That slight adjustment appears to move the parallel leg closer to the inbound leg:

 

[dtuuri]

[Sarcasm Alert]
And ***warning warning warning*** Don't dare get any closer to holding airspace or try to correct for the wind or, heaven forbid, intercept and track that outbound radial! After all, the gospel tells you

a) Parallel Procedure. When approaching the holding fix from anywhere in sector (a), the parallel entry procedure would be to turn to a heading to parallel the holding course outbound on the nonholding side ...​

No wind correction or tracking permitted or you will be struck down. Or at least prove to some that you are still in holding airspace.
[/Sarcasm Alert]

Kind makes insisting on 5° and not one degree more seem a bit silly, doesn't it?

First of all, you are misreading that paragraph. If there's a crosswind, in order to fly parallel you must correct for wind. See page 21, Par 27(b)(2) of the original study where they assume 15° of wind correction being applied. While you're there, notice that it isn't the crosswind they were concerned about, but the tailwind when coming from the parallel entry sector (they refer to it as the random). Also, note that they made allowances for reaction time when crossing the fix (six seconds) and delay in starting the clock. Reasonable thinking, based on my experience. So, again, refer to figure 2 in that document to see how far-flung from the fix you would be by the time you cross the inbound course using a teardrop vs. the "recommended" parallel.

I don't care what donkey bridge (Dutch saying, I'm told) you use as long as it can deliver on the 5° tolerance. That's what was and still is "considered to be within allowable good operating practice". To aspire for less, to me, is indefensible.

EDIT: One more thing. Prior to these procedures being developed there were no special maneuvers. The airspace was, IIRC (see the appendix to the document above), about ten miles long under TSO N20a(?). That's it. You were on your own. Can you imagine, today, foisting these procedures onto the magenta line kids literally overnight? Why there'd be tears and gnashing of teeth. Sobbing and revolution all over the country. In the mid sixties, they grumbled a bit, sucked it up and figured out how to enter within 5° of the correct entry every time.

dtuuri

 

[aterpster]

Attached is a PDF of holding at LAX VOR, with the smallest pattern, progressing through three increasingly large patterns to the largest pattern. These are the primary areas only. A secondary of 2 n.m. surrounds the primary area when used for obstacle clearance.

 

[midlifeflyer]

How does ATC figure out where to put an airplane in a hold an and develop the correct holding instructions?

I'm not sure what you are asking.

Unless an enroute hold is published, unlike the ones CFIIs and DPEs make up to see if we really understand what we are doing, the ones ATC typically gives are simple. They are just giving you a place to stop; they don;t want it any more complicated than you do. Chances are that, just like a Class D Tower telling you to circle over some visual waypoint outside the Class D, they know what is around and have a few places but need to come up with something fresh once in a while.

Example: You are on V62 between TAFOY intersection and SAF VOR on the way to Santa Fe, NM
https://skyvector.com/?ll=35.4787140967722,-105.77481078642809&chart=301&zoom=2&fpl=TAFOY SAF KSAF

There is other inbound traffic to KSAF so they need you to hold (no radar coverage down to the surface there) until the traffic lands. ATC might simply say. "Hold southeast of the Santa Fe VOR. Expect further clearance at..."

Does that answer your question or did I misunderstand it?

 

[aterpster]

I'm not sure what you are asking.

Unless an enroute hold is published, unlike the ones CFIIs and DPEs make up to see if we really understand what we are doing, the ones ATC typically gives are simple. They are just giving you a place to stop; they don;t want it any more complicated than you do.

Example: You are on V62 between TAFOY intersection and SAF VOR on the way to Santa Fe, NM
https://skyvector.com/?ll=35.4787140967722,-105.77481078642809&chart=301&zoom=2&fpl=TAFOY SAF KSAF

There is other inbound traffic to KSAF so they need you to hold (no radar coverage down to the surface there) until the traffic lands. ATC might simply say. "Hold southeast of the Santa Fe VOR. Expect further clearance at..."

It's not that simple, particularly at a mountainous-area airport like SAF. Ironically, there is charted holding pattern on the 152 degree radial. ATC could use that, or they could use one of two other published (but not charted on the en route chart) holding patterns.

Attached is the Radio Fix and Holding Data Record for the SAF VOR. As you will note, ABQ Center must use one of those three patterns unless you are at, or above, 12,600.

I suspect they charted Pattern 2 because that works the best for them. Pattern 3 is the GPS pattern, which required evaluation of the next larger templates vice Pattern 2.

The statement that unplanned holding must be at 12,600 or higher, indicates to me that the center's MIAs (polygons) are insufficient in area to contained unplanned holding below 12,600.

Typically, to keep it simple, the controller would simply say, "Hold southeast of Santa Fe VOR as published. Maintain X,XXX." Once in the pattern they could descend you to as low as 8900 (or 9,000).

 

[coloradobluesky]

Do they draw in on their screen? Draw it on a piece of paper? Do they use a DG to figure out where the approach is from the hold? Do they have a template or some aid?

I'm not sure what you are asking.

Unless an enroute hold is published, unlike the ones CFIIs and DPEs make up to see if we really understand what we are doing, the ones ATC typically gives are simple. They are just giving you a place to stop; they don;t want it any more complicated than you do. Chances are that, just like a Class D Tower telling you to circle over some visual waypoint outside the Class D, they know what is around and have a few places but need to come up with something fresh once in a while.

Example: You are on V62 between TAFOY intersection and SAF VOR on the way to Santa Fe, NM
https://skyvector.com/?ll=35.4787140967722,-105.77481078642809&chart=301&zoom=2&fpl=TAFOY SAF KSAF

There is other inbound traffic to KSAF so they need you to hold (no radar coverage down to the surface there) until the traffic lands. ATC might simply say. "Hold southeast of the Santa Fe VOR. Expect further clearance at..."

Does that answer your question or did I misunderstand it?

 

[fiveoboy01]

Thanks. Let's modify the heading to 015 instead of 025, like this:

1) ATC’s instructions are, “Bugmaster AB123, Hold W of the ABC VOR on the 270 radial, make right turns”; and

2) your heading to the ABC VOR is 015 (instead of 025)

That way - I think - we're more clearly in the parallel entry world.

Winds calm, and given a Cessna 172 doing 90 kts, would the actual flight path for the entry and the hold look something like this?

Given your numbers, I think that should be a direct entry, not parallel. But it's close enough that either way could work. My method mathematically makes that a direct entry though. By 5 degrees anyways.

 

[fiveoboy01]

I take that back. It's been a while since I have calculated a holding pattern in my head and now that I have my brain straightened out, it would be a parallel entry. Doh. My brain calculation was off by 10 degrees

Anyways, I can share my method which is a combination of what my CFI taught me and my own methods.

A - What's your heading? (015)

B - What's your holding radial(or outbound course)? (270)

Now, take the direction of the turn. Is it right? If the outbound course is within 70 degrees to the right of your heading, it's a teardrop. If it's within 110 degrees to the left, the entry is parallel. Anything else is direct.

Reverse for left hand turns.

Also as said, if you quick draw it on a map, or you have the fix up on your GPS and can visualize the direction of the hold, it's pretty easy to just determine by looking what your entry will be.

Me, I had a hard time with these so I downloaded a holding pattern app on my ipad and drew them in a notebook then checked the "answer" to see if I was right. After drawing probably 50 or so, I finally found it "not difficult" anymore. But as you can see, I still screw them up

 

[SkyHog]

It depends what the pilot is doing. My answer to SkyHog's right 270, initially away from the hold, is a definite "I dunno." And I'd even agree that a turn away from the hold merits an explanation on a check ride.

I just saw this - why would you turn away? In what I'm describing, you would hit the fix and turn outbound, following that turn all the way around into the outbound leg. It would look like this (although, hopefully not quite so sloppy since I can't drag a mouse as straight as I can fly a plane):

In this scenario, i forgot to draw the arrows showing direction of flight, so the narrative is that the pilot flies directly to the fix, turns right all the way around to the outbound leg, then flies the outbound leg, turns inbound, flies the inbound leg, then turns outbound, etc. etc..

 

[azure]

In this scenario, i forgot to draw the arrows showing direction of flight, so the narrative is that the pilot flies directly to the fix, turns right all the way around to the outbound leg, then flies the outbound leg, turns inbound, flies the inbound leg, then turns outbound, etc. etc..

Nick, in your picture, what would you do if you were coming from the NE instead of due east? (I'm assuming up is north.) In any case, turning directly onto the outbound leg is VERY nonstandard and from some directions (e.g. northeast in your picture), very awkward, in other words involving a lot of turning.

It sounds as if you're advocating a direct entry no matter what direction you approach the fix from. Considering that there are alternatives, I have to ask why.

 

[midlifeflyer]

It's not that simple, particularly at a mountainous-area airport like SAF. Ironically, there is charted holding pattern on the 152 degree radial. ATC could use that, or they could use one of two other published (but not charted on the en route chart) holding patterns.

Attached is the Radio Fix and Holding Data Record for the SAF VOR. As you will note, ABQ Center must use one of those three patterns unless you are at, or above, 12,600.

As always, thank you for the explanation, Wally. So there are indeed "preferred" locations for those holds.

It sure seemed that simple when I was given that exact hold on a flight.

 

[midlifeflyer]

I just saw this - why would you turn away? In what I'm describing, you would hit the fix and turn outbound, following that turn all the way around into the outbound leg. It would look like this (although, hopefully not quite so sloppy since I can't drag a mouse as straight as I can fly a plane):

In this scenario, i forgot to draw the arrows showing direction of flight, so the narrative is that the pilot flies directly to the fix, turns right all the way around to the outbound leg, then flies the outbound leg, turns inbound, flies the inbound leg, then turns outbound, etc. etc..

By "away" I simply meant the beginning of the direct entry initial turn, which heads at one point 180° away from the holding course. By "why would you" I meant why you would prefer a 270° turn to the outbound direction rather than of a 90° one.

I completely accept your explanation that you do it for consistency. To me that's your choice if it works. Although I still question whether even a small wind from the south in your drawing would result in leaving the template area.

 

[Palmpilot]

I just saw this - why would you turn away? In what I'm describing, you would hit the fix and turn outbound, following that turn all the way around into the outbound leg. It would look like this (although, hopefully not quite so sloppy since I can't drag a mouse as straight as I can fly a plane):

In this scenario, i forgot to draw the arrows showing direction of flight, so the narrative is that the pilot flies directly to the fix, turns right all the way around to the outbound leg, then flies the outbound leg, turns inbound, flies the inbound leg, then turns outbound, etc. etc..

Your sketch shows an abrupt right angle turn where the plane crosses the holding fix for the first time, which would require an impossibly tight turn radius. If instead a normal rate of turn is used, half of the turn would occur on the non-holding side, so the plane would enter the outbound leg at half the normal distance from the inbound course. Then, at the end of the outbound leg, the turn inbound would take the plane past the inbound course, thus requiring additional maneuvering to intercept it. (I don't know whether that's a problem or not.)

 

[fiveoboy01]

And as Mark alluded, any significant wind would make it even uglier.

 

[aterpster]

As always, thank you for the explanation, Wally. So there are indeed "preferred" locations for those holds.

It sure seemed that simple when I was given that exact hold on a flight.

If you mean the one you described in your earlier message, and if you were below 12,600, year 2006 or later, then they were violating the restrictions set forth on the holding record.

Why am I not surprised?

 

[dtuuri]

If you mean the one you described in your earlier message, and if you were below 12,600, year 2006 or later, then they were violating the restrictions set forth on the holding record.

Why am I not surprised?

Well, he said they said, "Hold southeast", so that would mean the charted 152° radial. However, I was left with the impression he held on V62 (104°) because of the simplicity of "stopping" there.

dtuuri

 

[midlifeflyer]

Well, he said they said, "Hold southeast", so that would mean the charted 152° radial. However, I was left with the impression he held on V62 (104°) because of the simplicity of "stopping" there.

dtuuri

That's correct, Dave. And the entire holding instruction was indeed

"Hold southeast of the SAF VOR. Expect further clearance at..."

And I sure hope I'm recalling correctly. I recall the instruction itself because of how short it was. It's been a while. But I don't recall a charted holding pattern there at the time. I know I looked for one because the instruction was so short. ATC definitely did not instruct to "hold as published"

 

[midlifeflyer]

Your sketch shows an abrupt right angle turn where the plane crosses the holding fix for the first time, which would require an impossibly tight turn radius. If instead a normal rate of turn is used, half of the turn would occur on the non-holding side, so the plane would enter the outbound leg at half the normal distance from the inbound course. Then, at the end of the outbound leg, the turn inbound would take the plane past the inbound course, thus requiring additional maneuvering to intercept it. (I don't know whether that's a problem or not.)

Out of curiosity, I tried it on one of the online simulators. I set up the hold we have been discussing, south of the VOR on R180, an aircraft flying inbound from the east at 100 KTS and a wind from 180° a 20. At the northern apex of the turn, the airplane was 1.9 NM north of the holding fix.

 

[aterpster]

That's correct, Dave. And the entire holding instruction was indeed

"Hold southeast of the SAF VOR. Expect further clearance at..."

And I sure hope I'm recalling correctly. I recall the instruction itself because of how short it was. It's been a while. But I don't recall a charted holding pattern there at the time. I know I looked for one because the instruction was so short. ATC definitely did not instruct to "hold as published"

Perhaps he had had so much problem relying on pilots locating the charted holding pattern that he said, "Hold southeast of SAF VOR on the 152 radial..."

Just for drill I am going to plot P10 on V62. I need to do that occasionally to maintain my proficiency.

 

[dtuuri]

Out of curiosity, I tried it on one of the online simulators. I set up the hold we have been discussing, south of the VOR on R180, an aircraft flying inbound from the east at 100 KTS and a wind from 180° a 20. At the northern apex of the turn, the airplane was 1.9 NM north of the holding fix.

Can you compare that track to one with a tailwind?

dtuuri

 

[midlifeflyer]

Can you compare that track to one with a tailwind?

dtuuri

You mean a wind from the east? Not able to do that now but I would expect no worse in terms of incursion onto the nonholding side than a parallel entry. I would expect a possible issue in terms of being blown pretty close to the course line when reaching outbound, but you need to worry about that even with a standard direct entry, although not as much.

 

[dtuuri]

You mean a wind from the east? Not able to do that now but I would expect no worse in terms of incursion onto the nonholding side than a parallel entry. I would expect a possible issue in terms of being blown pretty close to the course line when reaching outbound, but you need to worry about that even with a standard direct entry, although not as much.

Which online simulator did you use?

dtuuri

 

[aterpster]

I did an assessment of holding east on V62. This is with 1:24,000 topo data so it's quite accurate.

My conclusion: an MEA hold (10,000) fits fine. But, it is not documented so it is not a "planned" hold. If the center had asked the Aero Nav TERPs folks to evaluate this pattern, it would have passed muster and could have been documented on the 8260-2.

 

[SkyHog]

Nick, in your picture, what would you do if you were coming from the NE instead of due east? (I'm assuming up is north.) In any case, turning directly onto the outbound leg is VERY nonstandard and from some directions (e.g. northeast in your picture), very awkward, in other words involving a lot of turning.

It sounds as if you're advocating a direct entry no matter what direction you approach the fix from. Considering that there are alternatives, I have to ask why.

It's all about consistency. If you do the same thing every time, you greatly simplify what many consider tough.

Remember, the "eliteness" of flying is what keeps so many from succeeding. Make it easy where you can.

To the first point, if you are northeast, same deal. Always.

 

[SkyHog]

Your sketch shows an abrupt right angle turn where the plane crosses the holding fix for the first time, which would require an impossibly tight turn radius. If instead a normal rate of turn is used, half of the turn would occur on the non-holding side, so the plane would enter the outbound leg at half the normal distance from the inbound course. Then, at the end of the outbound leg, the turn inbound would take the plane past the inbound course, thus requiring additional maneuvering to intercept it. (I don't know whether that's a problem or not.)

I'm not saying it's correct. Clearly, it isn't what's taught, so by default it is incorrect, but this is how it should be done.

That said, the small drift to the non-protected side that would occur only during the initial turn would be minimal. Does it really matter?

 

[fiveoboy01]

Eliteness? Try money.

Anyways, entries are not hard if you practice them on paper now and then. Do enough and figuring it out becomes easy.

2 miles away from the fix as shown in Mark's example isn't small and that's with a 20 knot wind. Give me the parallel entry and I at least stay close to the hold. Start doing it your way with some of the winds you can find aloft and youre going to get even further from the hold.

 

[Palmpilot]

...2 miles away from the fix as shown in Mark's example isn't small and that's with a 20 knot wind. Give me the parallel entry and I at least stay close to the hold. Start doing it your way with some of the winds you can find aloft and youre going to get even further from the hold.

If the plane were coming in at 70 degrees to the holding course instead of the 90 that Nick drew, then making a direct entry would be FAA-approved. Is that 20 degree difference going to matter all that much?

 

[fiveoboy01]

Apparently the person who created the various entries thinks so.

 

[Palmpilot]

Apparently the person who created the various entries thinks so.

That would matter if you were flying the hold at speeds comparable to the maximum permitted speed. I suspect Nick is talking about planes that don't have enough speed, and a large enough turning radius, for the size of the protected area to be an issue.

 

[fiveoboy01]

Ok, so we will make different entries for different aircraft?

That just clouds the issue further.

 

[Palmpilot]

Ok, so we will make different entries for different aircraft?

That just clouds the issue further.

If you fly both jets and piston singles, I can see how that could be a problem.

 

[fiveoboy01]

Well I sure don't... I'll never fly a jet. I just don't really think it's an issue. Holding pattern entries are, in my opinion, one of the harder parts of the IR initially, but the rating is known to be difficult anyways. Study up, and it becomes easier

 

[Kritchlow]

Any modern jet I have ever flown has this all coded in the FMS. Nobody figures anything out, but we do make an earnest effort to verify its correct.

I would think all the fancy GA avionics would be well above that....

 

[Palmpilot]

Thanks to this thread, I think I'll find it easier to remember which way the 70-degree line goes if I ever become eligible to fly IFR again.

I just don't have any reason to criticize Nick's approach if he's not flying anywhere near the holding speed limit.

As for technique, if the hold is not charted, I found drawing it to work best for me.

 

[fiveoboy01]

Any modern jet I have ever flown has this all coded in the FMS. Nobody figures anything out, but we do make an earnest effort to verify its correct.

I would think all the fancy GA avionics would be well above that....

Garmin just(or is sometime this month) releasing an update to their GTN units that lets you create a hold basically anywhere.

I have a 430W and if there's a hold as part of a missed approach or a course reversal, it's charted on the moving map and my autopilot will fly it, including the entry. I'm not aware of a way to create an ad hoc hold with it.

I just doodle the hold on my notepad and go from there. I don't expect it to happen much in real life after I get the rating.

 

[Kritchlow]

Garmin just(or is sometime this month) releasing an update to their GTN units that lets you create a hold basically anywhere.

I have a 430W and if there's a hold as part of a missed approach or a course reversal, it's charted on the moving map and my autopilot will fly it, including the entry. I'm not aware of a way to create an ad hoc hold with it.

I just doodle the hold on my notepad and go from there. I don't expect it to happen much in real life after I get the rating.

You should be able to create any hold you want.... I do not know your system but I'm guessing you can make a waypoint anywhere you like... p/b/d or p/b/p/b, or even Lat/long. From there insert that waypoint and build a hold. Again, don't know your system but betting that's possible.

 

[fiveoboy01]

I can create a waypoint anywhere yes, but I don't think I can actually create/overlay the racetrack on the moving map with that waypoint as the holding fix. I could be wrong on that, I'm still learning the box.

 

[Palmpilot]

I can create a waypoint anywhere yes, but I don't think I can actually create/overlay the racetrack on the moving map with that waypoint as the holding fix. I could be wrong on that, I'm still learning the box.

I think you can use OBS mode to define the inbound course to whatever fix you want to hold at. Having the box display a racetrack pattern is not really necessary, because you can fly the hold the same as you would using a VOR receiver.

 

[fiveoboy01]

I was going to talk about the OBS mode, but I thought what he was getting at was the full hold depicted(which you can do with the GTN series boxes).

 

[Palmpilot]

I don't know. If the feature exists in that model, presumably it would be described in the manual.