Leaving a holding pattern

[LeNautilus]

Hi All,

I've found on an approach chart this kind of situation:
-holding pattern over a VOR: inbound course 048°, right turn,
-ILS procedure: starts from the VOR on track 254° (downwind leg) and then later on, right turn to intercept the approach course.

It's a 154° left turn to join the downwind leg from the inbound course of the holding pattern.
Is it legal to do such a turn? Or would you do a right turn come back over the VOR and then continue on the downwind leg?
The chart is not giving any indication how to do it and I haven't found the info in any documentation.

Thanks for your answers!

[Nightrider]

When passing the VOR you stay in the holding, means a right turn, and continue towards the VOR. shortly before reaching the VOR you turn left to intercept the approach track 254°. This is the only way to stay inside the protected area....and more important, you stay clear of the departure path of the runway in use.

[Thone1]

I completely agree.
A holding has to be left via the fix, whatever turns you fly, you have to stay on the "holding side" as this is the only area where a safe ground separation is guaranteed.

*...*

Cheers,

Thomas

[LeNautilus]

Thanks guys.
That's also what I thought as it's the most sensible way of doing.

[Gooneyone]

I may be wrong, but to start outbound you need to cross the fix within +/- 30 degrees of the reciprocal of the outbound leg which in this case means you need to do a course reversal.
Cross the VOR, continue outbound for one minute on the 048 radial then turn right to intercept the 074 radial inbound, then proceed outbound on the 254 having crossed the VOR.
Hold altitude should be at or above MSA.

[Thone1]

I meant to ask you that in my original post: Where is that approach?

Thomas

[LeNautilus]

Thone1,
You might have flown this approach already, it's in Stuttgart, for rwy 07. I'm using a LIDO chart.
The holding is at TGO VOR, which is South of the airport.

Gooneyone,
If you fly on the 048°, you get closer to the airport. And I think the rule of 30° is to start a reciprocal turn or a racetrack pattern. This is just a downwind leg.

LeNautilus

[Gooneyone]

I'm not familiar with the term "downwind leg". Are you referring to a base turn, which takes you outbound then turns you on to the ILS? If so, the course reversal is required.
I'm also not familiar with the approach plate. Any chance of posting a copy - that would help.

[Mintheskies]

http://www.opennav.com/pdf/EDDS/ED_AD_2_EDDS_4-2-2_en_2008-07-31.pdf

If link doesn't work there it is
http://www.opennav.com/pdf/EDDS/ED_AD_2_EDDS_4-2-2_en_2008-07-31.pdf
http://nav.vatsim-germany.org/files/edgg/charts/edds/public/EDDS_ILS_RWY07.pdf

Charts are old and I'm doubtful they're true but that's the only stuff I cared to look for (else I did find a Stuttgart up to date chart, but in Arizona, or Arkansas, anyway yankee city).
I reckon they might have changed since there is an obvious problem to me regarding how the TGO part of the procedure is designed.

To me looks like Nightrider and Gooneyone got the right answer : keep the inbound track a bit after passing overhead TGO, then right turn to join radial 074 inbound (QDR 074 ?), which depending on your acft category, will require or not a slight left turn to join the track. Your own cuisine, still might work.

OR you could "build your own reversal turn" : it's a 1'23" outbound leg radial 048 outbound then right turn (standard rate 3° per second) and you should end up with your manhood right on the 074 inbound track, says my old instructor. This corrected for wind effect. Not necessarily dangerous as long as you stay above MSA, which seems to be 4,700'.

OR, safest solution in flight, request vectors.

[LeNautilus]

Great links meintheskies,
The approach depicted is the same as I have on my chart. I am calling "downwind leg" the part which is on track 254°, parallel to the runway. Same as on a visual approach.
I understand that in "real life" you'd most probably get vectors but I am getting ready for a sim assesment.
Based on what was said earlier on, when flying over the VOR, at the end of the inbound, right turn to come back to the VOR and then anticipate a left turn to intercept the 254°. I think building my own procedure turn would make it too complicated. Staying on the protected side of the holding should be sufficient.
Thanks for contributing.

[cosmo kramer]

Deleted my first reply, since I misread your question.

Stay at 5000 feet, at the holding inbound TGO, fly over TGO and turn left heading 209 to incept and follow radial 254 outbound (the "downwind" Initial Approach segment). When established at the radial descend to 4000 and continue the procedure. You are above the MSA in the turn and don't need to be concerned about protected airspace.

Incidentally, this is how the 737 FMC would do it as well.

As I wrote in my deleted reply, I would turn lead a mile or 2 before the VOR to avoid too much overshoot.

*edited for wrong radial*

[Microburst2002]

MHA is higher than highest MSA, so the holding protection is not an issue here.

Maintain not lower than 5000 and save fuel, time, money and global warming: After overflying Tango, fly right until a say 270-280º track and intercept the 254º radial. When stablished you can descend to 4000. There is no hurry to descend since you still have plenty of miles to touchdown.

If instructed to commence approach during the outbound, justturn right and intercept the 254º.

If instructed during the inbound, continue to the VOR and right to incercept.

[cosmo kramer]

You spare the earth of more global warming by turning left, like I wrote :)

[Gooneyone]

Sorry folks, I don't agree. TGO is listed as the IAF, which means that the 254 Radial is the outbound leg of the approach. If you mean to do it "by the book", you must cross TGO then fly outbound on the 048R then turn right to fly back to the TGO planning to cross TGO within +/-30 degrees of the reciprocal of the outbound leg.
If you can get another clearance, that's fine, but that's the way Jeppesen states it as from Doc 8168. If you are doing a sim assessment, it might be worth your while to clarify this with the instructor during the brief.

[Gooneyone]

Further to my last post, have a look at the site below. Pages 23/24/25 cover the area we are discussing. Hope this helps

http://goacp.chc.ca/ACP%20Documents/Pre-course%20assignment/ICAO%20DOC%208168.pdf

[bookworm]

PANS-OPS requires a course reversal to be entered from within 30 degrees of the axis. But this isn't a course reversal, is it? The downwind leg from TGO is not a course reversal, just an ordinary initial approach segment. I'm with cosmo -- left turn. But I have to confess to being slightly embarrassed at not being able to point to a specific regulatory reference that confirms that.

[cosmo kramer]

The key is the IAF. Doc 8168 specifies only the +/-30 if no IAF exists.

Reference:
Chapter 3 INITIAL APPROACH SEGMENT
3.2 TYPES OF MANOEUVRES
3.2.1 Where no suitable IAF or IF is available to construct the instrument procedure in the form shown in Figure I-4-1-1, a reversal procedure, racetrack or holding pattern is required.

3.3 FLIGHT PROCEDURES FOR RACETRACK AND REVERSAL PROCEDURES 3.3.1 Entry
3.3.1.1 Unless the procedure specifies particular entry restrictions, reversal procedures shall be entered from a track within ±30° of the outbound track of the reversal procedure. However, for base turns, where the ±30° direct entry sector does not include the reciprocal of the inbound track, the entry sector is expanded to include it.

By flying the holding you already overflow the IAF. How you position yourself for the Initial Approach Segment doesn't matter as long as you don't descend before established. I would say ATC would expect that you establish yourself in the shortest possible way though, hence the left turn.

By the way:

Chapter 3 INITIAL APPROACH SEGMENT
3.1 GENERAL
3.1.1 Purpose
3.1.1.1 The initial approach segment begins at the initial approach fix (IAF) and ends at the intermediate fix (IF). In the initial approach, the aircraft has left the en-route structure and is manoeuvring to enter the intermediate approach segment.
Corresponds pretty good to the approach in question. Only thing we want to accomplish is to get safe to the IF before the beginning of the Intermediate Approach segment (the segment that is constructed for us to slow down and lining us up for an intercept for the final approach.

To do this maneuver as required and descend when established.

[Spendid Cruiser]

The key is the IAF. Doc 8168 specifies only the +/-30 if no IAF exists.
It states only that reversals are required if there is no IAF. As far as I am concerned entry to a reversal with an IAF is limited as per the +/- 30º requirement.

But I have to confess to being slightly embarrassed at not being able to point to a specific regulatory reference that confirms that.
Course reversals are defined in detail in the ICAO Flight Procedures doc. If it doesn't fall under that definition, as you have already identified, then it is just and Initial Approach Segment as also defined in the docs.

Stay at 5000 feet, at the holding inbound TGO, fly over TGO and turn left heading 209 to incept and follow radial 074 outbound (the 254 "downwind" Initial Approach segment). When established at the radial descend to 4000 and continue the procedure. You are above the MSA in the turn and don't need to be concerned about protected airspace.
The outbound course is radial 254?? Anyway, I think a left turn is incorrect. As previously mentioned, you must keep your turns on the side of the hold, so the only option as I see it, is a right turn until you're on an intercept course for the initial approach segment. Not only is it a requirement to stay within the protected area of the hold, but given speeds of 4 nm/min, proximity to the high activity area and the spot heights I couldn't justify a left turn over TGO.

Incidentally, this is how the 737 FMC would do it as well.
The 737 FMC will just calculate the shortest path to the next waypoint and has nothing to do with any requirements.

[cf6-80c2b5f]

Is it possible that the approach was never intended to be initiated from the published hold at TGO? Could the holding at TGO simply be for the missed approach procedure?

If you look at EDDS 10-2, the REUTL FOUR ALPHA and the TEKSI 4 ALPHA arrivals use TGO as an initial approach fix for RW 07. The REUTL FOUR is inbound to TGO on R163 and the TEKSI Four is inbound to TGO on R077. Both of these routes seem to fit in better than initiating the approach from the published hold at TGO, although it doesn't solve the problem of what to do on a missed approach after you get to TGO and hold.

[bookworm]

Anyway, I think a left turn is incorrect. As previously mentioned, you must keep your turns on the side of the hold, so the only option as I see it, is a right turn until you're on an intercept course for the initial approach segment.

That doesn't seem consistent with what you write above. It is, as you say, just an initial approach segment. Why is there a requirement to "keep your turns on the side of the hold"? After passing TGO inbound for the final time, the hold is irrelevant.

The REUTL FOUR ALPHA is inbound to TGO on R163

which is a 90 degree left turn on reaching TGO. If you're prepared to make a 90 degree turn transitioning at the IAF from STAR to initial approach segment, why wouldn't you make a 154 degree turn from the hold to the initial approach segment?

[cf6-80c2b5f]

Quote:
The REUTL FOUR ALPHA is inbound to TGO on R163
which is a 90 degree left turn on reaching TGO. If you're prepared to make a 90 degree turn transitioning at the IAF from STAR to initial approach segment, why wouldn't you make a 154 degree turn from the hold to the initial approach segment?

Good question. Could it be that 90 degrees is the limit?

3 INITIAL APPROACH SEGMENT
3.1 GENERAL
3.1.1 Purpose
3.1.1.1 The initial approach segment begins
at the initial approach fix (IAF) and ends at the intermediate
fix (IF). In the initial approach, the aircraft has
left the en-route structure and is manoeuvring to enter
the intermediate approach segment.

. . . .

3.1.2 Maximum angle of interception of
initial approach segment
Normally track guidance is provided along the initial
approach segment to the IF, with a maximum angle
of interception of:
a. 90° for a precision approach; and
b. 120° for a non-precision approach.

(Doc. 8168)

348 (inbound to IAF) - 254 (outbound after IAF) = 89 degrees.

[Microburst2002]

This thread is a little bit like those Bizantin arguments about angel's sex.

First, we have to estate wether we are supposed to be under radar coverage (which is the most likely scenario) or it would be "conventional" ATC.

If in radar control the left turn is probably the thing to do, but better do it considering TGO as a fly by and not as a fly over intersection and fly slow enough so as not to invade the airspace overhead the airfield.

In in conventional control, they should tell you what to do.

As long as you are above the MSA and you don't make an incursion in someone else's path, you can do whatever you want.

[cosmo kramer]

Let's not mix things up, the Standard Instrument Arrival has nothing to do with it:
3.1.2 Maximum angle of interception of
initial approach segment
Normally track guidance is provided along the initial
approach segment to the IF, with a maximum angle
of interception of:
a. 90° for a precision approach; and
b. 120° for a non-precision approach.
This 90/120 deg requirement is for the transition between the initial and intermediate segment. The IF is 11.4 DME TGO on radial 254. Hence the incept angle in this case is 0 degs.

P.s.
Splendid, you are of course right about the radial, don't know what I was thinking when I wrote that :ouch:

[cosmo kramer]

One more thing. Just one advice for your check, not just relating to this question in paticular. Bear in mind that no checkers knows everything. Just look how different answers you get on this question. (30 deg, 90 deg, whatever you like, can't do it from that holding at all!)

Hence, if the checker is the stubborn and nit-picking type (that at the same time is not aware of the above paragraph), you may do it one way or the other and he will say what you are doing is wrong anyway.

Beware of this kind of personality type. In this case, just have a good explanation ready for what you did if it will ever become an issue. If you show that you thought about what you were doing you might save the check anyway (even if you did it the right way, and he doesn't agree). Big discussions and hitting the checker in the head with the books is not the way forward in a hiring situation. Even if you are right, perhaps he'll get annoyed and fail you on some other mistake that you did, or tell that you have a bad personality.

No normal thinking checker would fail you for turning left or right out of that holding anyway. He is probably more interested in seeing that you are able to make the correct entry. In fact he would probably give you a vector when he feel that he have seen enough holding stuff. :ok:

Be consistent, do the same every time. In the unlikely event that you have to exit that holding twice (or any other situation where you are in doubt), do it the same way both times. It's easy to teach you to do something different once you get the job. But if you do thing differently with each maneuver it make you appear that you are uncertain of what you are actually doing.

[Sciolistes]

All I can find on the subject is this:
1.5.3 Departing the pattern

When clearance is received specifying the time of departure from the holding point, the pilot should adjust the pattern within the limits of the established holding procedure in order to leave the holding point at the time specified.
I could interpret this to back up the right turn view, just keep the turn in the hold going until on a suitable intercept course.

[aerobat77]

when hold over TGO and cleared for the approach you leave via the fix and then turn preferably right, not left . of course only leave holding when cleared for APP and report "passing fix". turning left would mean a sharp turn . the TGO VOR is pretty close to the airport and you must look not to shoot through the final segment. due to law you left the hold after last time passing the fix and even turning left is nothing wrong as long aircraft performance permits. - you in every case have to position yourself on R254 TGO and follow the published procedure. the second important thing is to keep 5000ft until established on radial and the decend to 4000ft. descend point on final is VATER out of 4000.

but i must say i was x times in EDDS and always had been vectored, never did the standart procedure. what can happen is that radar tells you "cleared for ILS 07, position yourself 10miles final and report established".

when someone can help how to insert a screenshot here i can provide you with the very last ILS 07 chart since i am sitting on a boring standby duty in the crewroom now. :(

[cosmo kramer]

1.5.3 Departing the pattern

When clearance is received specifying the time of departure from the holding point, the pilot should adjust the pattern within the limits of the established holding procedure in order to leave the holding point at the time specified.

...refers to that you should adjust your timing and inbound turn in the hold to exit the hold over the fix at the cleared time. If you are making one more turn to the right you are still in the holding and are leaving it on the outbound leg.

I guess you could also adjust your timing that it will fit that you can make the turn to the right and then immediately further right that you that you hit the fix again and leave. But what would be gained by that? By making a 360 over the fix, you nose will still be pointed in the wrong direction, and you would have to make a left turn anyway.

If making a right turn and go directly for the radial, without overflying TGO - when and where did you leave the holding?

I'll agree to the fact that it's academical with the procedure in question, due to the similar distance and time to be flow to get established on the 254 radial.
Microburst2002 has the right answer in my opinion:
As long as you are above the MSA and you don't make an incursion in someone else's path, you can do whatever you want.

As an side note I flew the said TGO holding pattern last winter when they were clearing the runway from snow. We left the holding on a radar vector. Only case I can think about where to leave that holding in the without instructions from ATC would be by com failure. In that case I would definitely go for the shortest direction left turn, because it clearly shows ATC without doubt that you are about to leave the holding pattern.

[aerobat77]

If you are making one more turn to the right you are still in the holding and are leaving it on the outbound leg.

factually you indeed in the first time do the same you would do still inside the holding , but due to law i think you left tgo holding after passing fix last time and reporting it - the next right turn is then not turning outbound but positioning yourself on the published radial- even when it is here nearly the same manouver as turning outbound.

[Thone1]

Having looked at the approach chart I hereby withdraw my previous answer.
Somehow I got my own drawing wrong.

Using TGO as an IAF, exit the holding via TGO, right turn, intercept Radial 254 outbound.
This keeps you in the protected area, away from the visual circuit (even though you´re at 5000´) and gives you an alignment towards the outbound.

Haven´t flown this one yet, unfortunatly.

Cheers,

Thomas

[Spendid Cruiser]

Bookworm,
That doesn't seem consistent with what you write above. It is, as you say, just an initial approach segment. Why is there a requirement to "keep your turns on the side of the hold"? After passing TGO inbound for the final time, the hold is irrelevant.
You will have explain where I was inconsistent. Regardless, ICAO says stay within the limits of the pattern. To me that means stay within the pattern as much as possible. In terms of airmanship, given that the hold is designed for 230kts, it is fairly obvious that a 737/A320 turning left would end up over or passing the airfield/approach area, that seems like an odd choice and even may take you outside of the buffer zone.

[marsipulami]

When looking at the chart you could see that the TGO holding is for the missed approach only (dashed line as explained in the legends?? section).

Also, if part of the procedure it would be depicted in the vertical profile of the approach.

When part of the procedure, the holding line would be of the same thickness as the approach track itself.

[aterpster]

bookworm:

which is a 90 degree left turn on reaching TGO. If you're prepared to make a 90 degree turn transitioning at the IAF from STAR to initial approach segment, why wouldn't you make a 154 degree turn from the hold to the initial approach segment?

No doubt the TGO hold is not part of the ILS Rwy 07 IAP. It is a general purpose hold, which could be used to absorb an arrival delay for the conventional arrival route over TGO. It is probably more likely used to park a missed approach although it is not a part of the missed approach, per se.

Let's say I am parked there on arrival or after a missed approach and am going to proceed on the south downwind leg for an approach (or another approach after a missed approach hold). This gets into technique as much as procedure since this is not a course reversal hold. What I would do, assuming approach control leaves me to my own devices, when cleared via the south downwind track, I would return to TGO in the hold, then do a right turn around to incercpet the TGO 254 radial (heading 300 would be a good choice), and not leave 5,000 until established on the 254 radial westbound. You will be within the holding pattern protected airspace until you are within the downwind track protected airspace.

[bookworm]

This gets into technique as much as procedure since this is not a course reversal hold.

But doesn't this miss the point a bit? Pilots aren't supposed to have to consider where protected airspace is in deciding which way to turn (granted, it's a useful thing to know about to stay alive, but the system doesn't require it). There are supposed to be only two methods of assuring terrain clearance under IFR. Either:

A) I'm radar identified and either on a vector or on a direct clearance where ATC is assuring the terrain clearance

or

B) I'm following a procedure that has been designed to be safe.

I find it hard to believe that having missed an approach, the only way out of the TGO hold is by radar vectors or an ATC-assured direct. In that case either:

1) It's up to the procedure designer to check that I can make a left turn from TGO with adequate terrain clearance

or

2) It's not up to the procedure designer to check that I can make a left turn from TGO, and the "procedure" requires me to make a right turn of the sort that you describe.

If the procedure requires a right turn, I'd like to see where in PANS-OPS that's described (I'm not challenging you, aterpster). If the procedure allows me to make a left turn, surely the appropriate "technique" is to make a left turn, because it's shorter -- I don't normally make 270 degree turns just for fun.

In this particular case, the MVA in the area of a left turn is only 3500 ft, so it is a terrain-safe manoeuvre. But I don't know if it would be in general.

[bookworm]

By the way EDDM has a similarly oriented hold, inbound axis 082 at MIQ, with a downwind leg of 227 to position for the ILS 08L. But on the AIP chart, there is a dotted line extending east of MIQ on 082, and at a particular DME the dotted track turns left to pass over MIQ again and out on 227.

The dotted line makes an appearance elsewhere where the holding axis and initial segment are significantly misaligned, but apparently not at EDDS.

[aterpster]

bookworm:
　
But doesn't this miss the point a bit? Pilots aren't supposed to have to consider where protected airspace is in deciding which way to turn (granted, it's a useful thing to know about to stay alive, but the system doesn't require it). There are supposed to be only two methods of assuring terrain clearance under IFR.

I don't see that I am missing the point at all. In the context of this thread the point is: how does a pilot get onto the approach from the charted TGO holding pattern without ATC providing radar vectors.?


A) I'm radar identified and either on a vector or on a direct clearance where ATC is assuring the terrain clearance

or

B) I'm following a procedure that has been designed to be safe.


I stated that there is some procedure and some technique aspects. The procedural aspect is that the holding pattern is a right turn holding pattern. The technique part is: what is the point in that right-turn holding pattern where you turn to intercept the TGO 254 radial? Further, there are two procedural minimum altitudes for this transition from the holding pattern to the TGO 254 radial; 5,000 for any portion of the holding pattern and 4,000 once tracking westbound on the TGO 254 radial. The MVA chart has no application whatsoever in this case; in fact, it appears to me that a portion of the holding pattern is in radar airspace of 5,000.

I find it hard to believe that having missed an approach, the only way out of the TGO hold is by radar vectors or an ATC-assured direct.

As well you should find it hard to believe because your premise is incorrect.

1) It's up to the procedure designer to check that I can make a left turn from TGO with adequate terrain clearance

There is no such requirement. The holding pattern is a right-turn pattern and the inbound course of that pattern melds with the centerline of the TGO VOR at the VOR.

At EDDM, the procedure designer did design an alignment turn to depart the holding pattern. This could be because of separation requirements set forth to the designers by Munich ATC; or it could have been a better designer at Munich, or Stuttgart ATC didn't want such a left turn maneuver because it would impinge on critical airspace. we have no way of knowing.


It's not up to the procedure designer to check that I can make a left turn from TGO, and the "procedure" requires me to make a right turn of the sort that you describe.

Repeating myself, it is procedurally a right-turn holding pattern. That means all turns to the right to remain within holding pattern protected airspace.

If the procedure requires a right turn, I'd like to see where in PANS-OPS that's described (I'm not challenging you, aterpster). If the procedure allows me to make a left turn, surely the appropriate "technique" is to make a left turn, because it's shorter -- I don't normally make 270 degree turns just for fun.

Neither PANS-OPS nor TERPS permits a left turn in these circumstances. The technique part is whether you elect to return to first return to TGO to make the requisite right turn, then continuing around to intercept the 254 radial (two separate maneuvers, procedurally), or whether you turn right to intercept while already established outbound in the holding pattern (a more economic maneuver if already outbound when approach clearance is received, rather than returning to TGO.)

In this particular case, the MVA in the area of a left turn is only 3500 ft, so it is a terrain-safe manoeuvre. But I don't know if it would be in general.

The MVA chart is not a pilot navigation chart and, in any case, the MHA is 5,000 and a portion of the pattern is in three different MVA sectors, the highest of which is 5,000.

[Sciolistes]

Bookworm,
I'd like to see where in PANS-OPS that's described (I'm not challenging you, aterpster).
Where indeed? You know how difficult the relevant documentation is to read, you've commented as such in the past. It is a case of joining the dots. But there are statements relating to hold buffer aeras. My take on these things is that the very mention of which makes it absolutely obvious that the expectation is that aircraft are to remain within.

[bookworm]

I don't see that I am missing the point at all.

I'm sorry, the way I phrased that was unnecessarily confrontational. The point is that a left turn from the inbound to TGO is either protected or not. In your later post, you unequivocally state:

Neither PANS-OPS nor TERPS permits a left turn in these circumstances.

which addresses the question, in this case, quite directly.

But the more general case (and how it applies to this one) is not clear to me. Under what circumstances is a "short" turn from the hold into the initial approach segment not permitted?

Turning to the "technique" aspect:

What I would do, assuming approach control leaves me to my own devices, when cleared via the south downwind track, I would return to TGO in the hold, then do a right turn around to incercpet the TGO 254 radial (heading 300 would be a good choice), and not leave 5,000 until established on the 254 radial westbound.

But hang on a moment, once you pass through the holding axis on a heading of 300, that leaves you at 5000 ft on the wrong (NW) side of the hold tracking up without course guidance to intercept the initial segment. Why is making up that manoeuvre (which is not depicted on the chart) guaranteed to keep you above terrain, while a left turn after TGO is not?

My take on [statements relating to hold buffer aeras] is that the very mention of which makes it absolutely obvious that the expectation is that aircraft are to remain within.

The procedural aspect is that the holding pattern is a right turn holding pattern.

But I've left the hold after passing TGO, haven't I?

[aterpster]

bookworm:

But I've left the hold after passing TGO, haven't I?

If you turn left at TGO, you most certainly have departed the holding pattern. :)

[Sciolistes]

But I've left the hold after passing TGO, haven't I?
Good question. Your intention is to leave the hold, but you're clearly still in the protected area/buffer zone (whatever it is best called) whilst you turn right. I suppose that technically, during that right turn then you still are in the hold until such time as you have crossed the inbound leg on your way to intercept the intermediate.
But hang on a moment, once you pass through the holding axis on a heading of 300, that leaves you at 5000 ft on the wrong (NW) side of the hold
I think aterpster means that you continue a right turn until a track of 300º is achieved, that would place you in the with hold pattern area for most of the manoeuvre and WSW of TGO.
Why is making up that manoeuvre (which is not depicted on the chart) guaranteed to keep you above terrain, while a left turn after TGO is not?
It seems to me that turning left would probably take you 4nm away from TGO over the runway and short final and over the 2,000' spots for the intermediate intercepts. Conversely turning right should keep you with the 1000' clearance buffer zone of the hold and within 5º of the intermediate (or much closer and for much longer than a left turn) and away from the 2,000' spots.

[bookworm]

I think aterpster means that you continue a right turn until a track of 300º is achieved, that would place you in the with hold pattern area for most of the manoeuvre and WSW of TGO.

For "most" of it, yes. But you cross the axis and move to unprotected side before intercepting the 254 radial. So there's no more guarantee of terrain clearance than there is with a left turn from TGO. In practice, of course, there is terrain clearance in both cases, but as aterpster says, the pilot shouldn't use the MVA chart to make decisions about the correct procedure.

It seems to me that turning left would probably take you 4nm away from TGO over the runway and short final and over the 2,000' spots for the intermediate intercepts. Conversely turning right should keep you with the 1000' clearance buffer zone of the hold and within 5º of the intermediate (or much closer and for much longer than a left turn) and away from the 2,000' spots.

In practice, in this particular case, it does look as if a left turn takes you close to the airfield, but that should be no more a consideration in which way to turn in a charted procedure than the MVA chart. In practice the controller will be vectoring you, or, more likely these days, telling you to fly to DS430!

I'm sorry for labouring this one, but it does seem that there's still an ambiguity. If I'm inbound on track 343 to TGO on the REUTL4A arrival and cleared for the approach with no mention of the hold, surely I'm supposed to make a 90 degree left turn on to 254, and the procedure designer is supposed to check that I can do so safely, because it's part of the classic arrival-approach depicted in PANS-OPS fig I-4-1-1 "Segments of instrument approach". But because there's a hold depicted there turning left from the inbound leg is suddenly unprotected?!

What about the other IAF, LBU? That's a left-hand hold, inbound on 178, with the initial approach segment on the 233 radial. That's a 55 degree right turn. Leaving that hold, am I really supposed to turn 305 degrees left (or more likely 330 with an intercept)?

[bookworm]

You will have explain where I was inconsistent. Regardless, ICAO says stay within the limits of the pattern. To me that means stay within the pattern as much as possible.

OK. Earlier you wrote:

Course reversals are defined in detail in the ICAO Flight Procedures doc. If it doesn't fall under that definition, as you have already identified, then it is just an Initial Approach Segment as also defined in the docs.

If its "just an Initial Approach Segment" and not a course reversal, why would you not turn the short way to establish on it?

[aterpster]

bookworm:

I'm sorry for labouring this one, but it does seem that there's still an ambiguity. If I'm inbound on track 343 to TGO on the REUTL4A arrival and cleared for the approach with no mention of the hold, surely I'm supposed to make a 90 degree left turn on to 254, and the procedure designer is supposed to check that I can do so safely, because it's part of the classic arrival-approach depicted in PANS-OPS fig I-4-1-1 "Segments of instrument approach". But because there's a hold depicted there turning left from the inbound leg is suddenly unprotected?!

Indeed, if you arrive via the TGO 343 radial (without an instruction to hold) you turn left to intercept the 254 radial. And, in my circumstance of being in the hold then turning right to a heading of 300 degrees to intercept the TGO 254 radial, I would subsequently turn left from that 300 degree heading to intercept the 254 radial.

[Sciolistes]

Bookworm,

Two distinct issues. One was a response from somebody stating they didn't know where the definition for a reversal was and the other is discussing the issue in hand - leaving a hold.

Blooper: I see that I have been writing "intermediate" when I meant to write "initial" :O Perhaps that clears it up?

I'm advocating the green route.

http://dl.dropbox.com/u/6615175/EDDS.JPG

[bookworm]

Useful diagram. The blue route you draw is an interesting one: you assume anticipation of the TGO (fly-by) for the REUTL4A arrival, but not for leaving the hold.

If you allow similar anticipation, and scale the size of the hold to reflect the radii you've drawn, then there are a number of other possibilities. One is to make a left turn from the beginning of the inbound leg, but then one starts to ask "why not simply roll out of the inbound turn on a heading of 300?" Which is not so dissimilar from the green route!

If you don't allow such anticipation, the blue route is not so far away from the red route.

If you draw the same diagrams for the LBU hold, I think you'd be hard pressed to reject that 52 degree right turn on to the initial approach 230 track. That's much less extreme than the turn from the BADSO1A arrival. But one can keep finding examples of such holds at different angles (take a look at EDDF), so where do you set the limit? Is it "30 degrees max or you must manoeuvre in the hold" as for a course reversal? But there's no mention of that in PANS-OPS.

You can see why RNAV/RNP is so popular... ;)

[Sciolistes]

Thanks, wobbly hand drawn so don't give too much weight to where the lines fall. Yes, I was thinking about that anticipation. I think the 737 FMC would anticipate the turn on the IAF, but would pass fly over the 11.4d point before turning. But if you don't anticipate then you fly through TGO and onto the other side which is what we have been saying one should avoid!

One is to make a left turn from the beginning of the inbound leg
I think you may intercept 254º later than desirable (in reality, at 230kts the hold would be much bigger than drawn), IMHO best keep the right turn going until a suitable track for intercept of the initial has been attained.

[aterpster]

Turn anticipation shown arriving from REUTL to TGO, 5,000 feet, 240 KIAS, standard atmosphere, no winds aloft.

http://tinyurl.com/23pqthh

[DFC]

Can I start this post with a plea - that might seem obvious - at a turn point always turn the shortest way to the next track (unless there is something specified to the contrary).

Seems that some people have forgotten this very important principle and the fact that the turn area only protects turns in this direction.

Turns are specified either at a fix or at an altitude.

In this case TGO is a fix where a turn is specified.

This is not a reversal procedure (Procedure turn or base turn). Therefore the requirement to enter +/- 30 does not apply.

The fact that there also happens to be a hold at this fix is simply a distraction.

If cleared to proceed beyond the IAF one must cross the IAF.

If one is in the hold then when cleared for the approach one must route via the IAF and at the IAF turn in the shortest manner to establish outbound from the IAF.

At 5000ft one is terrain safe for the turn shortest way round and since one can not descend to 4000ft until established outbound in terms of when one can descend to 4000ft there is no gain by doing some unnecessary long turn.

Turning the long way round can cause a number of problems. Imagine how far the aircraft is going to drift during all that time when there is a very strong tailwind on the inbound leg of the hold. It is possible that some aircraft turning the long way round could end up pointing at TGO from the northeast. They would then have to cross TGO again (possible from an unplanned direction) and after crossing the fix turn right to establish outbound. The aircraft in this case would be in a situation where it is turning through was was designed as the inside of the turn area and the posibility of going outside the protected airspace is high.

Furthermore, one has to remember that the turn to establish on the Initial Approach segment must be made at a fix. If one continues the hold i.e. turns right at TGO then from the moment TGO is passed the aircraft is no longer tracking any navaid and is operating on DR. One simply compounds the problem here by trying to establish on the Initial Approach leg somewhere west of TGO.

The size of the protected airspace to cope with (the worst case) situation where and aircraft turns the long way round and then DR's to some point west of TGO will be far bigger than the airspace required for a simple turn.

ICAO 8168 is very specific with regard to fix tolerance for the IAF. Turning the long way round can negate the fact that TGO and the Initial Approach Leg complies with those requirements.

So in this case, no matter where one is in the hold, when cleared to proceed beyond the IAF one must route to TGO and at TGO - the specified turn fix - turn the shortest way round to establish on the initial approach.

Remember that the altitudes charted are minimum altitudes. There is no rush to get down to 4000ft just to fly level for an age. While I don't know what the local plan is, Non-Radar, procedural I would not be holding an aircraft at TGO, 5000ft with another aircraft on approach because if there is a missed approach you have a conflict. There is plenty of room to hold 1000ft above the missed approach altitude and once established on the initial approach, just look at all the miles available to loose 2000ft.

If it is not procedural (non-radar) then hey you are going to be vectored!! :)

[aterpster]

DFC:

Remember that the altitudes charted are minimum altitudes. There is no rush to get down to 4000ft just to fly level for an age. While I don't know what the local plan is, Non-Radar, procedural I would not be holding an aircraft at TGO, 5000ft with another aircraft on approach because if there is a missed approach you have a conflict. There is plenty of room to hold 1000ft above the missed approach altitude and once established on the initial approach, just look at all the miles available to loose 2000ft.

In this hypothetical discussion we don't know what the local plan is, either. But, it is a fact that the TGO 228 radial holding pattern is shown on an ILS 07 arrival chart, as well as on the approach chart. So, it is presumably there to absorb arrival delays on occasion as well as provide a terminus for the missed approach. If arrivals are held there on occasion, perhaps they are held at 6,000, or higher. Or, perhaps if arrivals are held there then alternative missed approach instructions are issued to an aircraft on the approach. We don't know any of that.

If radar vectors are used, then perhaps the missed approach holding becomes moot; or perhaps the arrival holding becomes moot.

The point of the hypothetical is: what is the best manner in which to depart the hold for the ILS 07 approach whether an arrival or a missed approach airplane. Turning left at TGO is not the prudent option. Returning to TGO if outbound in the hold may not be the best option, either.

However, turning left in a fly-by maneuver southwest of TGO is the proper method on arrival from the south without the hold being assigned. The illustration above shows how a modern FMS would calculate and excute the course change from the TGO 163 radial to the 254 radial absent the holding pattern.

As to descent, modern FMSes don't descend any sooner than necessary. "TOD" (top of descent) along the 254 radial in the illustration on Post 46 is where an aircraft arriving at 5,000 from the south would leave 5,000 for 4,000--well after being established on the 254 radial.

[Sciolistes]

Can I start this post with a plea - that might seem obvious - at a turn point always turn the shortest way to the next track (unless there is something specified to the contrary).

Seems that some people have forgotten this very important principle and the fact that the turn area only protects turns in this direction.
Shortest by what measure? Track miles or distance from the IAF? Turning left or right here achieves one but not the other!

Also, by my reckoning, if a medium jet turned left out of the hold it would intercept the initial just in time to start the descent. If it turned right it would have a nm to spare.

Neither tailwinds or DR is relevant as a right turn would stay with the holding pattern until a track of 300º had been achieved to intercept the initial.

It doesn't matter what way you cut it, staying south of TGO for any manoeuvring is covered by the hold, the initial and the arrival buffer areas.

[DFC]

Shortest by what measure?


By angular change. When pilots are expected to turn onto a new track or heading they are expected to turn "the shortest way" which means through the angle that is the smaller of the two options available.


Also, by my reckoning, if a medium jet turned left out of the hold it would intercept the initial just in time to start the descent. If it turned right it would have a nm to spare.




When cleared to leave the hold the aircraft must route to the IAF. From that moment on the hold is no longer an issue. The IAF in this case is a fix where a turn is specified and when the aircraft reaches ther IAF it is expected to make the turn towards the outbound track. This turn has nothing to do with the hold and the turn should be made towards the outbound track no matter what direction the turn fix is approached from.


Neither tailwinds or DR is relevant as a right turn would stay with the holding pattern until a track of 300º had been achieved to intercept the initial.




It is very relevant.

The only time it is not relevant is when the aircraft is tracking inbound to or outbound from TGO. While turning the aircraft is being drifted downwind. From the completion of the turn until the aircraft has established on the outbound radial the aircraft is operating on DR. The amount the aircraft drifts during the turn depends on how long the aircraft spends turning. the amount the aircraft drifts on the DR leg to intercept depends on what wind info is available and how the pilot uses it.

The easiest way to look at this is to remember that you want to spend the minimum amount of time with no tracking information. You do not help yourself in this regard by increasing the time spent turning.

Finally, it is very possible that having turned the wrong way, when a track of 300 is acheived the aircraft will be positioned in such a place that a track of 300 will not intercept the outbound radial and will fail tom return to TGO. not a good place to be eh?


It doesn't matter what way you cut it, staying south of TGO for any manoeuvring is covered by the hold, the initial and the arrival buffer areas.


In the buffer area, you do not have obstacle clearance guaranteed. Within the hold area obstacle clearance is guaranteed. In the holding area the obstacle clearance is based on the aircraft following a specific procedure and always regaining the inbound track and following it to the hold fix - TGO.

You fail to recognise that with a strong northerly wind, your aircraft will establish on the track of 300 some way south of the still air point for the start of the hold outbound leg. The aircraft will then track 300 which will cause it to miss TGO and leave the holding area. How do you know that where the aircraft leaves the holding area it will be within the middle half of the Initial Approach area (wher obstacle clearance is assured? Or that it will be within the turn area designed for a correct direction turn?

The turn fix is TGO. Treat it as such - a turn fix - a turn at the IAF. Forget the hold as soon as you are cleared beyond the IAF and route to TGO where you make an appropriate turn to establish outbound and not to fly tyhe hold again (unless you want ATC to repeat the clearance to proceed beyond the IAF because it looks to them that you are flying another hold) and they do not expect you to turn the wrong way.

[9.G]

I'll take a simplified look at that, being at 5000 ft is above MSA in all sectors (highest being 4700) thus it doesn't matter which way one turns as long as 5000 is maintained till established on 254 outbound. However I'd agree with the shortest way version simply coz the box would do it too. MVA in this sector is 4000 ft and then 3500 on downwind, so I presume that's what ATC will do as well. In this context 5000 ft holding over TGO is more suitable for MA.:ok:

[Sciolistes]

DFC,

Apart from TGO being a fix, I don't think I agree with anything you've written. I suspect in the absence of any clear an unambiguous guidance it is left to judgement. We've each made our points and we're not going to agree :\

[DFC]

No problem.

I am using DOC8168 as a reference.

What are you using?

Can you provide some reference to DOC8168 or TERPS that shows a turn area constructed for a "long way round" turn?

As someone said earlier, will you turn in the direction of the hold at the other IAFs when given onward clearance?

[Sciolistes]

Using the same ICAO doc, standard fare in the Jepps on the flight deck.
As someone said earlier, will you turn in the direction of the hold at the other IAFs when given onward clearance?
Would I keep the turn as much as possible within the 1000' clearance buffer area in IMC? Yes I would :ok:

[aterpster]

DFC:

Can you provide some reference to DOC8168 or TERPS that shows a turn area constructed for a "long way round" turn?

In this hypothetical there is a holding pattern we are parked in and there is a straight initial approach segment. The holding pattern at this location mandates right turns, which may seem to be the long way around if viewed as a "turn area" rather than a holding pattern.

Another aspect is that the charting makes the pattern appear to not overlap the initial approach segment. If you construct either the TERPs or the PANS-OPs containment areas for both the holding pattern and the R-254 initial approach segment, you will see that the holding pattern containment area extends well beyond the centerline of the TGO 254 radial.

I'll construct both the pattern and the initial segment using TERPs and post it. PANS-OPS would have some differences but they would not be significant.

[aterpster]

This is a to-scale illustration of the TGO holding pattern (230 knots @ 6,000) primary containment area and the TGO 254 radial initial approach segment's primary containment area. (using U.S. TERPs).

http://tinyurl.com/2avq4pd

[DFC]

PANS OPS has some quite significant differences. However, let's stick with one standard even if it is not the applicable one.

Can you please construct a turn area based on an aircraft flying inbound to TGO on the same radial that is the inbound leg of the hold and making a left turn at the fix?

Can you also plot the primary and secondary areas of the various holding and initial approach sectors you have described.

Thank you :cool:

As I said, being in the hold is simply a distraction and there is absolutely no requirement to continue in the hold once given onward clearance.

Having designated TGO as a turn fix the procedure designer has to design the turn area - in the appropriate direction. They do not expect aircraft to turn in the wrong direction. The protected airspace for the turn will be different from the protected airspace for the hold and by turning the wrong way you can cause problems because once established inbound in the hold, if then cleared to proceed beyond TGO on the Initial Approach leg, ATC are entitled to assume that you will turn left and base separation on that.

You could find that for example an aircraft which is established inbound on the hold and cleared for the approach is deemed separated from an aircraft on a departure because the departure protected area and the turn area (to the left) do not intersect. If you turn right without clearance you can cause big problems.

So like I said - can anyone give me an example from PANS-OPS or TERPS of a turn at at fix which is initially away from the desired onward track?

[DFC]

Would I keep the turn as much as possible within the 1000' clearance buffer area in IMC?


That is not what I asked.

I asked - Would you turn the wrong way at any of the other IAF's?

The procedure designer will have contructed a turn area - why do you feel the need to make up your own procedure?

Can you give us an example of another situation where you will turn the wrong way simply because there is a hold (which you are not cleared to follow) at the turn fix?

[aterpster]

DFC:

Can you also plot the primary and secondary areas of the various holding and initial approach sectors you have described.

I don't think we are communicating. The immediately preceding illustration shows the primary areas for both sectors, as you call them. The secondaries are irrelevant to this discussion, but they are two miles wide around the holding pattern and on each side of the initial segment primaries. I chose to leave them off for clarity and to show the airspace that is protected for ATC purposes, assuming non-radar ops.

There are not significant differences between PANS-OPS and TERPs except for the visual circling areas. An airplane doesn't know whether it's inside a cloud in Germany or Colorado.

As to "turn areas" as you call them, there would not be any turn area construction for a turn at TGO absent being in the holding pattern.

This horse has been beat enough.