Holding at IAF of RNAV

[Bladeangle]

Am keen to hear opinions (and actual references) in regards to holding at the initial of an RNAV (not published for holding) at a referenced MSA.

Have spoken to a local CASA FOI, seems to think it is NOT on at all because it is not a surveyed area. Fair enough, but if I am referencing a charted GRID or MSA with a GPS and requesting traffic from ATC why not?

Had a good look and I cant find anything on it...

[Oktas8]

The purpose of surveying a published holding area is to ensure that terrain clearance is achieved for the (surprisingly large) volume taken up by a holding pattern with all possible entries and all assumed winds, at maximum permitted IAS. It's expensive, but done to allow holding below Grid LSALT or MSA.

If you're holding above minimum safe altitude (MSA or whatever) and have accounted for maximum GPS error and the maximum size of the hold with the wind of the day, then it's safe. But make sure that you're far enough inside the MSA boundaries to make your MSA still valid even with all these cumulative error margins.

Pages GEN 3.3 -15 to -18 apply. Paragraphs 4.3, 4.6 and 4.9 would seem especially relevant to an unpublished GPS holding pattern.

Cheers, O8

[alphacentauri]

Couple of different thoughts on this.....

First, with my procedure design hat on. Holds are placed and protected not just to avoid terrain. There may be other considerations, like deconfliction with holding patterns for other procedures or clearance from other aerodromes and traffic. So from this point of view I would say it is a good idea to hold only where there is a published holding pattern.

From a pilot point of view. If you are within the 25nm MSA and can garauntee you will stay there and separate from other aircraft, then you are allowed to manouver as required within the MSA area at the MSA. After all, that is what the MSA is designed for.

In the world of litigation you should consider the following. If you do decide to hold away from a published holding pattern and you hit something or someone and cause damage. At the subsequent coroners enquiry the prime question will be; Why did you hold at an unpublished holding point? In thinking about your answer to this question add "Your Honour" to the end and see if you can come with an answer that doesn't sound irresponsible.

Food for thought....personally I'd be sticking the published patterns.

[MACH082]

If you're in a high performance aircraft your hold may take you over the instrument approach, or the missed approach.

If there are other aircraft using the approach you could become a hiderence to their operation.

If you have an emergency, all bets are off. Do what you need to do to satisfy the best outcome for your passengers and company asset.

[spocky]

Bladeangle, Feel free to hold at the IAF and make your own holding pattern...as long as the pattern is above the MSA or Grid there will be no problems.

However, if the MSA (unlikely) or Grid is at an altitude that would require you to do a steep descent after leaving the IAF, that would defeat the purpose of a stabilised approach. If that's the case just stick to the published pattern.

For what it's worth, we make our own holding patterns in the simulator quite often !!

Spock

[Bladeangle]

Thanks for the input thus far guys.

Confirmed my thoughts on the subject. Some good points, especially on procedure design, eg missed approach.

As for the FOI, he purely said "you can not hold anywhere there is not a published holding pattern". I walked away from him at this point thinking he might have actually had some knowledge on the subject of flying.

You shouldn't really need to do a sector entry at an rnav unless you were holding, would be easier to simply manoeuvre so that you fall within the capture region of one of the IAF's.

Cheers BA.

[nitpicker330]

What rubbish.

You can hold anywhere you damn well please as long as you are above MSA or en route LSA etc and can stay inside them.

Some people........

[alphacentauri]

Nitpicker, ask the blokes that held in the missed approach at Launceston a few years ago if they can 'hold anywhere'. After coming face to face with another aeroplane I'm not sure they will agree with you.


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[neville_nobody]

So when Centre says make standard pattern at 30DME on the 300 radial we are supposed to say 'unable'?

If you are above the MSA you can do as you please.

[alphacentauri]

If centre clear you for holding, then it becomes centres responsibility to clear you from other traffic, and (if in CTA) terrain. If you are above MSA then fill your boots, because centre is looking out for you

But OCTA...different story. The responsibilities are now yours. Terrain is easy to clear from, as everyone has stated. But conflict with other traffic, holding patterns, approaches, etc...well thats not so easy to clear from.

Perfect example of this are the position of the holding patterns at Cootamundra and Wagga RNAV's. If you hold wherever you like there is a good chance you will be in conflict with approaches at the other airfield. Conflicting traffic will be on another freq...bit hard to say you can guarantee separation.

Again, ask the guys involved in the Launceston incident if they thought holding where they did was a good idea.

[nitpicker330]

Well obviously ATC and Traffic permitting. Did I need to state the bleeding obvious?????:sad:

[Skydiveandy]

Bladeangle

The FOI may have been referring to the new requirement for ATO's to only test holding patterns on a published holding pattern.

This is fairly new and is only relevant to initial and renewal tests. This is only for testing and nothing else..

Andy.

[Jack Ranga]

"you can not hold anywhere there is not a published holding pattern"

Find another FOI

[Captahab]

from alphacentauri's post above
First, with my procedure design hat on. Holds are placed and protected not just to avoid terrain. There may be other considerations, like deconfliction with holding patterns for other procedures or clearance from other aerodromes and traffic. So from this point of view I would say it is a good idea to hold only where there is a published holding pattern.

Your theory is great but the reality of most NDB and VOR approaches are designed that the aircraft carrying out a missed approach will fly straight through the published holding pattern at the same level as the minimum holding altitude (YMAY Rwy 25 VOR as an example)
Why is it ok to design that way for those but not for holding on an RNAV as you imply.

You can hold anywhere as long as it is above the MSA and you have to use common sense to overcome the design flaws in both published and random holding patterns to avoid others.

[alphacentauri]

Yeah ok....I'll bite

With the YMAY VOR 25 plate open in front of me, the difference in height between min holding alt and minima at the Mapt is 2200ft. The missed approach gradient is only 2.5%, where you will reach 3400ft approximately 14nm away from the airfield.

Exactly how much clearance do you want?

[Captahab]

Are you saying that an Ejet or Q400 will only climb at 2.5% ?

[alphacentauri]

No, I am saying that is the gradient we use for clearance.

In the Albury case you would have to climb at nearly 8% for there to be a conflict.

[Captahab]

OK, now apply your theory to YMIA VOR Rwy 09 for a cat C a/c.

The holding should have been designed as a left pattern (still 290 inbound) to cater for missed approach, right works in (office) theory eh !

There are dozens designed this way when a little bit of reality consideration would have shown the the design flaws and hopefully the simple fix !

Please don't try to tell me that I can't use common sense and fly a left hold to avoid an a/c ahead on the approach if they go around.

[alphacentauri]

You'd have to climb at 5.5% to conflict with aircraft at the start alt in the pattern.

But if you have just left the aid at the start alt, only a foolish person above you in the pattern or joining the pattern would join at the altitude you have just left, especially as you would only be 300ft below them as turning inbound.

Please don't try to tell me that I can't use common sense and fly a left hold to avoid an a/c ahead on the approach if they go around.

According to everyone else on here you can hold anywhere....But let me ask you a question. If you do fly a left holding pattern and you hit someone/something, how are you going to defend youself. Does your ops manual include CASA approval to change the published direction of holding patterns as you see fit?


The turn direction of the pattern at Mildura would only have made a marginally better conflict with the missed approach....the holding pattern protection is huge and the change is conflict would be minimal

[Captahab]

5.5%, piece of cake.

Why (design) overlay the hold and the missed approach path in the first place.

[Captahab]

The turn direction of the pattern at Mildura would only have made a marginally better conflict with the missed approach....the holding pattern protection is huge and the change is conflict would be minimal

Nonsense, only potential overlap would have been at the navaid/missed approach point.

With the existing published procedure both a/c could/would be converging as they tracked away from the navaid.

You are in the process of confirming my thoughts on why we have poorly designed approaches.

[alphacentauri]

Nonsense, only potential overlap would have been at the navaid/missed approach point.

You sound like you know what you are talking about. How about you draw a holding a pattern protection area for Mildura and prove what you have just said.

You are in the process of confirming my thoughts on why we have poorly designed approaches.

I wouldn't be too quick to criticise something you don't understand.

[Captahab]

You sound like you know what you are talking about. How about you draw a holding a pattern protection area for Mildura and prove what you have just said.

Have a look at Rocky VOR Rwy 33, that is what I mean. The missed approach avoids the holding pattern but you are saying that it doesn't work ?

If the Mildura holding pattern was flipped over then it too would be clear of the missed approach and would look similiar to the Rocky VOR Rwy 33 situation.

Look, I agree that there are many things about the design that I know nothing about but on an almost daily basis I encounter aspects of design that could be improved and are often not realised until you are in the situation.

Joe bloggs in his unpressurised 402 etc doesn't have the ability to descend on the approach at 1000' per minute and may not have been exposed yet to the implications of arriving in the hold at the minimum altitude.

I am not planning on getting into a who is intelligent or stupid argument as a tiger poster has alluded to above, I am trying to highlight the fact that a small change in the design stage can make a big difference to the hands on application world. Its an area that the person with the rules and the CAD needs to consider, that's all I am saying.

Compare the location of the hold vs the MA on Mildura and Rocky and you will see what I mean - maybe its just me who thinks it could be better :oh:

[Zoomy]

Just my two cents.

If you need to hold on the approach and are inside and above the MSA then why wouldn't you fly over to the published hold. That way you fly straight down the approach without any more turns. :ok:

[MakeItHappenCaptain]

Please don't try to tell me that I can't use common sense and fly a left hold to avoid an a/c ahead on the approach if they go around.

Umm, dude, you can't use common sense and fly a left hold if the plate depicts a right hold.

ENR 1.5
3.1.3 Right turns holding patterns are standard holding patterns and must be flown unless the AIP chart depicts, or ATC directs, otherwise.

Broascasts at Non-Towered Aerodromes;
Instrument approach when, a. departing FAF or established on final approach segment inbound
b. terminating the approach, commencing the missed approach

Comms will allow the parties to organise separation if required.
There is no minimum distance outbound in the hold before you turn back in if you think there will be a conflict with an a/c in the missed approach in your scenario..:ok:

[Captahab]

Umm, dude, you can't use common sense and fly a left hold if the plate depicts a right hold.

Ease up on the dude stuff, this is the Aust part of DG&P, not Brokeback Mountain where you are :E

[MakeItHappenCaptain]

Not the first and won't be the last person I say that to.:ok::}
In the film Easy Rider, Billy (Dennis Hopper) speculates that George (Jack Nicholson) "must be some important dude". When George asks what the word "dude" means, Wyatt (Peter Fonda) tells him "dude means, uh, nice guy, dude means regular sort of person".

[alphacentauri]

Captahab, I do see what you are talking about. On the face of it I cannot dispute your logic. But it appears to me that you are working on deconflicting nominal tracks, whilst I have to deconflict protection areas. We really aren't comparing the same thing. Which is why I can't dispute what you say. But If I were to show you the design areas for these approaches you may be surprised how different they are from what you think they are. (and you wouldn't be the first pilot to be surprised at the approach protection areas)

[alphacentauri]

Don't talk crap.

Of the 6 designers currently certified by CASA. 4 of us hold or held ME-CIR. The other 2 were rated ATC looking for a change in career.

We currently have 3 trainees all of which have the minimum experience to design procedures as set by CASA.

We are currently recruiting so I can assume we will get your application since you reckon you can do our job better than us.


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[Captahab]

Captahab, I do see what you are talking about. On the face of it I cannot dispute your logic. But it appears to me that you are working on deconflicting nominal tracks, whilst I have to deconflict protection areas. We really aren't comparing the same thing. Which is why I can't dispute what you say. But If I were to show you the design areas for these approaches you may be surprised how different they are from what you think they are. (and you wouldn't be the first pilot to be surprised at the approach protection areas)

Another area of consideration that you touched on with your 2.5% example is that you were probably measuring that from the navaid. In most cases for a Rwy approach the missed approach (vertical aspect) is commenced once you reach the MDA which can be a long way before the navaid, the navaid is still used but only for lateral tracking to and point of direction for change of tracking if published.

[Oktas8]

In most cases for a Rwy approach the missed approach (vertical aspect) is commenced once you reach the MDA

The 2.5% (or other if specified) gradient starts at the published missed approach point. No sooner, no later. This usually isn't where the ideal profile intersects MDA - there's almost always a level segment.