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How does your company describe circling approaches?

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How does your company describe circling approaches?

Old 10th Dec 2013, 12:32
  #61 (permalink)  
 
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But where are the times noted in the FCTM, or any document?

Ive been taught it in the sim, and used it on the line but have never seen it mentioned in the books.

Visual approaches I don't use timing and just use an extended centre line and dme readings as a cross check.
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Old 10th Dec 2013, 14:04
  #62 (permalink)  
 
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Ive been taught it in the sim, and used it on the line but have never seen it mentioned in the books.
I have only seen detailed explanations in the material supplied by my flight school during my initial instrument training.
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Old 10th Dec 2013, 14:07
  #63 (permalink)  
 
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B737900er, it's not described in the FCTM. In my opinion it is not within the responsibility of Boeing either, but the airline to make a decision of the appropriate method, given they may operate under different regulations or set higher requirements than what is regulated by the authority.

As I wrote previously, e.g. my airline decided to raise the circling minima to 3000 meters visibility given the fast speed of the -800. Hence, min visibility and timing are interconnected, and at my airline it has been considered as show in the calculation in my post on page 1 of this thread (before the discussion was derailed by AirRabbit). Another airline could in theory decide on 5 km min visibility and describe the circling as a visual approach if so inclined.

I think most of us would agree that a visual approach is flow looking out the window, with the only necessary working instrument being the airspeed indicator.
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Old 10th Dec 2013, 14:43
  #64 (permalink)  
 
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Cosmo - cheers for the clarification.

I recall seeing a sentence in the FCTM that timing is no longer the preferred method due to the available functions of the FMC (presumably the fix page).

Funny enough I can no longer find that statement in the newest revisions.
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Old 10th Dec 2013, 18:46
  #65 (permalink)  
 
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Originally Posted by cosmo Kramer
I am not criticizing your experience, which I have no possible way to evaluate or judge. What I am saying about your experience is I don't care!
…and you’ve made that abundantly clear.

Originally Posted by cosmo Kramer
This is a discussion forum, what counts here are what arguments and knowledge you present. Your post are longwinded, full of adjectives and small anecdotes that are irrelevant to the point.
Irrelevancy is often in the eye of the reader … and not all readers read the same thing into what is written … which is why I diligently attempt to say the same things differently to allow for just those kinds of potentials. Obviously, I haven’t yet found the formula to allow some here to understand my points. However, I guess I should offer my “thanks” for the compliment on my writing “style.”

Originally Posted by cosmo Kramer
I didn't eat 5000 meals crossing the Atlantic (too young and also no desire), I don't waste my time doing lunch meetings. I became a pilot because I like flying, to which such activities are contra productive.
I wasn’t saying that you DO eat 5000 meals crossing the Atlantic – I was attempting to refute that specific allegation … which you made as I’m sure you recall the following...
Originally Posted by cosmo Kramer
(And yes, I don't care how many hours you have... eating a meal and taking a nap 5000 times over the Atlantic doesn't really make anyone an expert in circling approaches).
…which was most certainly thrown in my direction.

Originally Posted by cosmo Kramer
I don't care how many hours you have, or how many Pepsi's you drank or canapés you ate at some lunch-meeting being an international "negotiator".
…and, just in case you continue to have that opinion, I think you might want to know that there are some here who do spend some valuable time in, as you describe, “international lunch meetings,” but I would suspect that they each believe they are contributing to the overall safety of ALL the world’s aviation operations – and very few, if any, of whom are specifically aware of, nor likely care, that you think they are wasting their time.

Originally Posted by cosmo Kramer
I do however, operate a 737-800 (as PIC if that matters to you, you seem very hung on status) into dark desolated (no MacDonalds to steer for) 1 runway-1 taxiway airports, surrounded by mountains on a regular basic. And occasionally do a circling at said airports (because the mountains do not allow to approach from either side). That I do according to the SOP of my company in a safe and efficient manner, as I am paid to do.
My suggestion would be that you slow down your reading rate – just a bit – in order to comprehend what is written … you might recall that what I wrote was a very brief history of why the US rules were changed from what is essentially the language you described (which was … “the basic assumption is that the runway environment should be kept in sight while at minimum descent altitude/height (MDA/H) for circling.” I attempted to explain why the US chose to refine that kind of wording, in that the term “runway environment” was thought to be insufficiently accurate – as it was learned that some pilots were using objects that should never have been used for the purposes that some pilots were using them … hence the new language … as I said:
Originally Posted by AirRabbit
That language seemed to be adequate until it became apparent that the McDonalds Hamburger “Golden Arches,” the “Freeway Entrance Sign” and the “time and temperature display” for some business advertisement, that happened to be located across the street from the airport, adjacent to the runway soon came to be the kinds of things that pilots were using as circling and landing references. Unfortunately, the folks that own McDonalds’ franchises and all those other references are under no requirement to maintain their advertising or their signs in any particular manner and may, at any time, adjust, rebuild, move, or remove such signs. It became apparent that simply describing the “environment associated with the approach end of a runway” might not necessarily ensure that pilots who were using such references could be assured of a safe and accurate final approach segment and landing. It was at that time that the FAA changed the rules to cite “an identifiable part of the airport” for those required references … since airport diagrams are required and flight crews are required to have those diagrams with them when flying and buildings and structures on an airport are very closely regulated, marked, and shown on those airport diagrams.
I’m just trying to understand your thought processes, cosmo… because what you wrote doesn't seem to make sense ...
Originally Posted by cosmo Kramer
As you can see, it is the runway that should be kept in visual contact. Not airport surroundings. Neither does it say that the Pilot Flying, should be the one to keep the runway in sight, for multi pilot airplanes.
Originally Posted by cosmo Kramer
If you are on downwind, 1 nm past the threshold, still going in the opposite direction, you will not able to fly with reference to the runway.
So … which is it? "The runway is kept in visual contact" … or … "you will not be able to fly with reference to the runway" … ? You can do one or the other … but I would submit … not both at the same time.

...and, since, according to you, the requirement says "...Visual manoeuvring (circling), 7.2.2. After initial visual contact, the basic assumption is that the runway environment should be kept in sight while at minimum descent altitude/height (MDA/H) for circling"... just who should it be that keeps "the runway environment in sight while at MDA"??? I ask only because in most cases, directions that are issued regarding how the airplane is to be flown are directed to the pilot doing the flying. Right?

Originally Posted by cosmo Kramer
I don't say that to assert myself, but to explain the reason I felt I had something to contribute to this thread... What was your motivation, except for an opportunity to flash your, for your age quite (sorry) common CV?
So … am I to understand that when you post something, the motivation is pure and contains heartfelt comments from a professional aviator … but when someone like me posts something it can only be “an opportunity to flash my quite sorry (and) common CV?

Originally Posted by cosmo Kramer
If you take the time and look back in the thread, you will see that everyone here use the method I described (including US colleagues). That except for a few cheers to you from General Aviation pilots.
As I read back through this thread I see that there are some who, very definitely, indicate that they do much as you do. I also see that some describe what they do in a manner that could be taken in one of several ways – meaning I am unsure of the specifics of what they describe – and, of course, there are some here who describe their actions as being similar to the procedures I’ve described and some who simply agree with what I’ve posted. I would hope that no one here blindly takes anything written on any forum – including this very fine forum – as justification for changing the way they comply with the way their company wants them to perform. What I do hope for is that those here who are unsure or would like to examine their own understanding of the issue brought to light in this or other forums would take those questions to their training department and have a frank and open discussion about what should be done – and how the airplane is to be flown.

Originally Posted by cosmo Kramer
Face it, you are off track. And maybe it is time you review your perspective
.
Everyone is entitled to their own opinion – and that includes both of us.

Originally Posted by cosmo Kramer
By the way, why aren't you out drinking beer? Colleague doesn't want to pay anyway? Time to throw the towel in the ring.
Well, the fact is that when you posted your response to my post – I had made arrangements to do just as you suggest. In fact, since I’m not scheduled to work for another couple of days, I just might repeat that activity with some close friends who I’ve asked to take a read of this particular thread, specifically the thoughts you have expressed. If they’re printable, I’ll let you know what they say.

Last edited by AirRabbit; 10th Dec 2013 at 19:55.
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Old 10th Dec 2013, 19:58
  #66 (permalink)  
 
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So … which is it? "The runway is kept in visual contact" … or … "you will not be able to fly with reference to the runway" … ? You can do one or the other … but I would submit … not both at the same time.
I can indeed have both:
Fly (aviate) is maintaining altitude, altitude and speed. Or the longwinded version :
Every time you, as a pilot, move a control surface, make a power adjustment, or anything that will affect the existing condition of the airplane (and I use the term “condition” to mean the airplane’s attitude, altitude, airspeed, angle-of-attack, direction of flight, configuration, energy state, etc.), AND you should know that what you are doing is correct and proper to regain or maintain the airplane condition that YOU desire and/or the condition you want for the airplane in the next second … application by application.
You can't do that looking over your shoulder. Especially with mountains, strong wind and turbulence, your would have to work to keep the aircraft on the desired path, that may be with a very limited margin defined by MDA/cloudbase - being too close to do a 180 and too far to keep the runway or associated lights in sight. On a dark, poor vis, rainy night, I would even recommend you fly (aviate) with reference to your ADI, as previously described a few posts back. Not looking out the window for the nearest MacDonald.

Keeping the runway in sight is navigate. To rely on that sight alone for navigation, with all associated optical illusions due to darkness, rain, unusual altitude, poor runway lightning seen from an angle etc., I maintain is reckless.

So … am I to understand that when you post something, the motivation is pure and contains heartfelt comments from a professional aviator … but when someone like me posts something it can only be “an opportunity to flash my quite sorry (and) common CV?
I wrote because the subject interested me. And, frankly, there is an egoistical reason for all me to post on this forum too - my own benefit of being forced to look things up and refreshing my memory (like where is what exactly written).

You on the other hand jumped in with a completely off-topic post where you are trying to assert yourself as some master, who discovered a new trend before anyone else. There after, again "the master", is telling us everything we do is wrong and continue to "back up" your argument with a CV that is (sorry to say) not that particular extraordinary. It usually comes with growing older that you did a lot of "stuff".

Previous in my career I flew with 20,000 hour Captains, that didn't know the alternate planning minima and could handfly if their life depended on it (certainly not without the FD). So I learned that doing stuff for a long time is no guarantee of competence. In fact I have the experience that the less people feel they need to assert themselves, usually the more competent they are....



P.s.
I wasn't complementing your writing style, being clear, concise and to the point is something to admire. And "quotation marks" around a word means that it shouldn't be taken literal, that in fact the writer means something else than the typical meaning of the word or as a plain expression of irony.
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Old 10th Dec 2013, 20:36
  #68 (permalink)  
 
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Don't have time to read all of them now, but the first of you example, just begs for a comment, as it supports my case:
The pilots assumed this was a routine flight. After all, the weather was good and there was nothing wrong with their aircraft just minutes before landing.

As it turns out, the captain, who was the pilot flying, was compelled to attempt a night visual approach to the runway, even though the VOR Runway 17 instrument approach was briefed and set up earlier.
It just highlights that a night visual is a difficult maneuver, even into an airport with wich the crew was familiar at daytime.

Exactly the reason an even more difficult night-circling approach should be dealt with in an almost scientific systematic manner. It should not be taken lightly and regarded as a tight visual approach, and as such the timing method is a good system to ensure that you are where you want to be.
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Old 10th Dec 2013, 20:53
  #69 (permalink)  
 
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OK … I’m getting confused trying to stay up with what it is you are trying to say …

Originally Posted by cosmo kramer
Here is is no requirement to have the runway in sight, as long as you can find your way with other identifiable terrain features (e.g. follow a coastline that leads to the airport). Hence you fly it looking out the window…
Who “flys it” looking out the window? The pilot flying? The pilot looking out the window? Or is one pilot doing both? I thought you said that wasn’t the way you flew?

Originally Posted by cosmo kramer
You can't do that looking over your shoulder. Especially with mountains, strong wind and turbulence, your would have to work to keep the aircraft on the desired path, that may be with a very limited margin defined by MDA/cloudbase - being too close to do a 180 and too far to keep the runway or associated lights in sight. On a dark, poor vis, rainy night, I would even recommend you fly (aviate) with reference to your ADI, as previously described a few posts back. Not looking out the window for the nearest MacDonald.
When I described a pilot moving a control surface or making another flight control adjustment you come back with a statement that again says “…you can’t do that looking over your shoulder…” indicating that you can’t do that when looking out the window …?

Originally Posted by cosmo kramer
Keeping the runway in sight is navigate. To rely on that sight alone for navigation, with all associated optical illusions due to darkness, rain, unusual altitude, poor runway lightning seen from an angle etc., I maintain is reckless.
And here … we’re going back the other way … relying on looking out the window is a proper way to navigate, but it’s reckless.

I’m not trying to make you angry … I’m just pointing out an apparent lack of continuity in your thought process.

Originally Posted by cosmo kramer
You on the other hand jumped in with a completely off-topic post where you are trying to assert yourself as some master, who discovered a new trend before anyone else. There after, again "the master", is telling us everything we do is wrong and continue to "back up" your argument with a CV that is (sorry to say) not that particular extraordinary. It usually comes with growing older that you did a lot of "stuff.
Actually, I “jumped in” to comment on what appeared to be the generation (and acceptance) of yet another in a series of “cheat-sheet” methods to reduce the amount of flight awareness that simply must be maintained during flight operations. And I’m still not sure that what was being described is not one of those “feel-good-rules-of thumb” that have little to do with the task at hand. In fact, I cannot believe that with the amount of time and experience you claim, that you have not seen a pilot attempt to drag out from memory a set of specifically-committed-to-memory-values that is thought by that pilot to be “the way” to address the situation at hand. I wouldn’t be at all surprised to learn that the Asiana 214 tragedy involved at least some pre-conceived “it’s-always-worked-before” kind of “semi-procedure” that, when it was failing, because it HAD always worked before, neither pilot at the controls recognized that something was wrong and going even more wrong – until the stick shaker shook them back to reality just in time to push up the throttles and have the tail smack the sea-wall. You, and others who believe as you do, will just have to pardon the fact that my interest and commitment to urge the elimination of such “cheat-sheet” methods, because invariably they allow semi-competent pilots to attempt to operate airplanes with passengers aboard. My skepticism and my digging into what is visible only on the surface, together with others who share my concerns, has been one of my primary responsibilities for a good share of my career. I can appreciate that some don’t like to have something that they’ve become accustomed to doing to be criticized … but I would hope that understanding why such criticisms are made – that being to better ensure that pilots remain aware of what their airplane is doing, understand why it is doing that specific thing, and agree that what is being observed is what was asked for by the pilot at the controls.

So, please continue to attempt to belittle me or criticize my thoughts or motivations if you choose – you aren’t the first … and likely won’t be the last … and I say that because such criticisms do, on occasion, make sense, and requires those of us who believe the way we do that some additional issues have to be addressed. That is a good thing … and I don’t object … at all. However, apparent disconnects with the criticisms … an appearance to stubbornly hold on to issues that are inherently inaccurate or have been known to generate problems simply cannot be allowed to go unchallenged and uncorrected.

As I said previously – I hope you continue to operate safely and continue to enjoy the best profession on the planet.
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Old 10th Dec 2013, 21:14
  #70 (permalink)  
 
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I’m not trying to make you angry … I’m just pointing out an apparent lack of continuity in your thought process.
You apparently didn't read my posts.

Cirling approach, downwind, runway behind you, poor weather:
You can't fly (aviate) the aircraft looking out the window, because you may have nothing but a black windscreen a head of you. Hence, you are forced to fly on your ADI.

Visual approach, anywhere one the approach, runway might not even be visible (shallow fog, behind next mountain etc.), good inflight visibility, terrain features recognizable (airport up that valley, behind the next mountain):

Cosmo Kramer:
I think most of us would agree that a visual approach is flow looking out the window, with the only necessary working instrument being the airspeed indicator.
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Old 10th Dec 2013, 23:33
  #71 (permalink)  
 
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Originally Posted by cosmo Kramer
You apparently didn't read my posts.

Cirling approach, downwind, runway behind you, poor weather:
You can't fly (aviate) the aircraft looking out the window, because you may have nothing but a black windscreen a head of you. Hence, you are forced to fly on your ADI.

Visual approach, anywhere one the approach, runway might not even be visible (shallow fog, behind next mountain etc.), good inflight visibility, terrain features recognizable (airport up that valley, behind the next mountain):
This is just the kind of thing I’m trying to point out …

Originally Posted by cosmo Kramer
As you can see, it is the runway that should be kept in visual contact.

There is no requirement to have the runway in sight, as long as you can find your way with other identifiable terrain features…

A circling is rightly a visual maneuver, but flown in IMC conditions.

You are proposing to fly looking out the window when flying downwind. What visual reference do you expect to have?

I think most of us would agree that a visual approach is flow looking out the window, with the only necessary working instrument being the airspeed indicator.
My guess is that you’re having at least some difficulty in recognizing the fact that your statements directly contradict each other. That leaves those of us trying to understand a bit in “a fuddle.”

You say a visual approach is flown looking out the window. You’ve posted quotes from various sources that indicate that a “circle-to-land” is visually flown from the point in which you reach visual conditions until you land. You’ve also said that you cannot fly a circle-to-land if you have to look out the window. What does that mean?

You say that a circle-to-land is “rightly a visual maneuver but flown in IMC conditions.” Do those IMC conditions have a minimum value for you to be legal to initiate the approach? Where do you find what those minimum IMC conditions have to be? What do those numbers mean? What are you supposed to do with that information?

You’ve said that on a “Visual approach, anywhere on the approach, the runway might not even be visible.” Is there anything that the pilot must be able to see to fly a “visual approach” or is it just “the ground.” If it is just the ground – is there no particular object on that ground that must be seen?

If we intend to fly an instrument approach with a circle-to-land clearance, do you not think that those minimums are published for a reason? I’m curious – presuming the ceiling and visibility is exactly what is printed on the chart … what is it that you expect to be able to see when you get to the point where you are about to break off from the instrument approach and being the circle-to-land maneuver? Do you expect to see … the airport … the runway … or some other identifiable ground object? If it is some other object – how would you know what to look for unless it’s printed on the chart? If it is the runway and you later lose sight of that runway (which you say may happen) ... now, what do you do? If, as you say, you know that the runway might not be visible when you get down to circling minimums – why is it you believe you are authorized to begin the approach? Unless, of course, there is some other feature that you can identify visually … but what would that be? There are requirements that exist that tell you when you must initiate a missed approach … right? Would it not be that you lost sight of something – what is that something? Is it what you had in sight initially? What is it that you have to see to continue? Is that information included on the approach chart under "circling minimums?"

Cosmo, my friend … I think confusion is beginning to reign supreme … and it’s not me that’s confused.
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Old 11th Dec 2013, 03:36
  #72 (permalink)  
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AirRabbit, you have written quite a few words on this thread so far. However, I don't see your answer to the original question! Can we have a concise summary of how you would perform a circle to land procedure? For the example lets use a Cat C aircraft, Boeing 737 if you like.
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Old 11th Dec 2013, 03:51
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Originally Posted by Screwballs
AirRabbit, you have written quite a few words on this thread so far. However, I don't see your answer to the original question! Can we have a concise summary of how you would perform a circle to land procedure? For the example lets use a Cat C aircraft, Boeing 737 if you like.
Sure thing Screwballs – just let me know what airport, what runway to approach and what runway to land after circle, "existing" weather conditions, and, if you have access, an appropriate approach plate. If you don’t have one, I may be able to come up with one. I’ll await your information.

...and, as I've been saying, the reason I posted anything here is that it seemed to me that some inexperienced aviators may have thought it wise to jump on the series of suggested numbers that were being thrown around very casually. I know that many "newbies" have a tendency to take some of those "number references," commit them to memory for a given set of circumstances, and may at some point in the future be tempted to apply those "number references" to some different, but similar-looking circumstances, and without knowing for sure what they're doing, choose to apply the wrong application to the set of circumstances with which they have been confronted. There seems to be a marked increase in that kind of "cheat-sheet" approach when difficult sets of circumstances present themselves. I've said that I wouldn't be surprised to hear that the Asiana tragedy at SFO may have had just such an "its-always-worked-before" set of "canned procedures" that were used by that crew.

Last edited by AirRabbit; 11th Dec 2013 at 04:35.
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Old 11th Dec 2013, 04:43
  #74 (permalink)  
 
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Woah, chill out guys. The question ways about 'how your airline describes circling'. Just do it the way your manual tells you too, I have never done a circling approach in anywhere near minima conditions. I only use a timing method as that is how I was taught and it makes it easy in the Sim where the visuals might not be the best.
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Old 11th Dec 2013, 08:50
  #75 (permalink)  
 
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My current airline (as well as my previous one) solved this whole problem rather bluntly as reflected on the back of my certificate in the limitations section, which reads in part:

ATP CIRC APPCH - VMC ONLY
CL-65 ERJ-170 ERJ-190 CIRC APPCH - VMC ONLY

Besides, there are only two airports where we do any kind of circling with any kind of frequency, those being LGA and DCA, in the former case only if one is to consider Expressway Visual Rwy 31 a circling approach.
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Old 11th Dec 2013, 13:39
  #76 (permalink)  
 
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…..or set higher requirements than what is regulated by the authority.

e.g. my airline decided to raise the circling minima to 3000 meters visibility given the fast speed of the -800.


I did fly a CAT C a/c and the promulgated minimum vis was 2400m, as now. The local XAA FOI did a calculation regarding the radius of a continuos turn from downwind to finals. He concluded that 2400m was not enough to keep the runway in sight at the spacing required to make a rate 1 turn onto finals. He enforced 3600m (CAT D) on the airline. We disagreed by performing in the sim and found a downwind spacing of 2400m to be sufficient for the turn. No success. His opinion was that 2400m vis at 500' agl was not healthy and that was it. Minima are just that.
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Old 11th Dec 2013, 14:08
  #77 (permalink)  
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Sure thing Screwballs – just let me know what airport, what runway to approach and what runway to land after circle, "existing" weather conditions, and, if you have access, an appropriate approach plate. If you don’t have one, I may be able to come up with one. I’ll await your information.
A theoretical, sea level airport. 09/27 4000m nil slope dry runway. ILS on 09. Minima for Cat C. Company minima 1,000ft AMSL. Actual weather 10km visibility. Cloud base is minima plus 200ft(1,200ft). Nil significant weather. Wind is only 270/10. ATC request you circle to land on 27. Nil terrain issue, MSA in all sectors 1,100ft. Temperature 15. QNH 1013.25. Boeing 737-700 at a nominal weight. Approach speed 140. It's 1224Z on the 17th of February. 2012. You are on the prime meridian. The sun is up. If I haven't mentioned it, it isn't there.

So back once again to the original query: how do you describe the circle to land, specifically the downwind leg and turn from there through base to final?
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Old 11th Dec 2013, 16:58
  #78 (permalink)  
 
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Hi Screwballs - I'd be happy to describe how a circle-to-land maneuver should be conducted at the "theoretical" airport you have described ... but, in that you're describing a theoretical, not a real, airport, I doubt there is an approach plate available. As you would certainly recognize, having the information available on that plate is crucial to the performance of any such instrument approach - regardless of whether or not a circle-to-land is planned. While the information you provided is relatively comprehensive - there is substantial information that is not available in your description: the layout of the airport, including the locations of runways, taxiways, tower, hangars, fire departments, airport locator beacon, and other buildings, the location and elevation of any obstacles, the ceiling and visibility required for the approach, the ceiling and visibility required for conducting the circle maneuver, minimum altitude to maintain during the circle, other restrictions to any circle authorizations, limitations to and locations of appropriate reference points for the ILS to be flown (OM, MM, IM, FAF, MAP and the means used to identify those points), any instrument procedures and similar reference points for authorized instrument procedures for the runway of intended landing (if any), and, unfortunately, the list could go on rather extensively. In fact, a picture is worth 10,000 words. However, and I think importantly, before we get to whatever potential solution might be appropriate to answer your request of me … I think there may be a larger question to resolve first.

In your opening post you said…
Originally Posted by Screwballs
The reason I am wondering about is to do with the protected area and the tightness of the turn to final. Cat C aircraft will have 4.2nm to manouevre inside safely. And this is based on a max speed of 180 knots with a 25 wind plus correction for TAS gives a speed of 215 knots for the circling area. (Jepp Text pg. 233 Table I-4-7-2) However, with that speed and timing based on 1,000ft AAL circle to land, you would end up approximately 2.7nm from the threshold.* Plus a turn inbound would still give you a margin on the 4.2nm. And that's at 215 knots! The normal reality would be closer to approximately 160 knots or so.
I’m not sure what it is you are saying here. Why would you presume that you would have to circle at 215 knots? I think that if you check the approach plate for an ILS at any airport/runway you know well, you’ll find the distance from the OM to the runway threshold is on the order of 4.5 to 5.0 miles. You’re describing a “safe maneuvering radius” of 4.2 nautical miles, which is over 25,500 feet – more than twice the distance of some of the longest runways in the world. Additionally, the safe circling distance from the end of the runway you are describing would be just inside of that OM/FAF location. Given the fact that most ILS OM/FAFs are at 1500 feet AGL, and you’re describing a circling altitude of 1,000 feet AGL, it would seem to me that you should find yourself quite comfortable with those circumstances. The circling distances are calculated for the various categories of airplanes in accordance with their maximum gross landing weight and the airspeed they would have to maintain to be safe at those weights – plus whatever margin above that distance the airport/approach planners allow. Of course, we all recognize that a circle-to-land authorization does not guarantee that everything will work out well and that the landing is guaranteed. That’s why they have missed approach procedures. However, IF the airplane is flown carefully and within the parameters prescribed, and there are no unusual “winds aloft,” there is little reason that the approach and landing could not be safely accomplished – and they are – regularly. Again, my interest was initiated strictly due to what appeared to be the attempted structure of a “set of numbers” solution to a set of specific circumstances that inexperienced pilots might want to apply to a different circumstance that could easily get them into trouble. And, I continue to think there is more to learn about the Asiana landing accident at SFO along these specific lines.

However, given all these issues, if you desire that I describe how a specific circle-to-land should be flown, I can still do that for you, IF the information that is typically available on an approach plate is available for that description.

Last edited by AirRabbit; 11th Dec 2013 at 17:57.
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Old 12th Dec 2013, 00:41
  #79 (permalink)  
 
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It all depends on how sacrosanct your stabilised approach criteria is. If you need to be stabilised at 500ft AGL on final, you must turn base abeam that point (ie 1.6nm/2900m/40sec at 140GS). It is impossible to remain within circling visibility criteria from the threshold (we need to keep the runway environment in sight;not withstanding metallic obstacles to vision!) while still complying with the turn point.

Flyboy Mike's outfit realises that by ruling:
ATP CIRC APPCH - VMC ONLY
CL-65 ERJ-170 ERJ-190 CIRC APPCH - VMC ONLY
circling in VMC only.

and Rat 5's FOI was also onto it:
The local XAA FOI did a calculation regarding the radius of a continuos turn from downwind to finals. He concluded that 2400m was not enough to keep the runway in sight at the spacing required to make a rate 1 turn onto finals. He enforced 3600m (CAT D) on the airline. We disagreed by performing in the sim and found a downwind spacing of 2400m to be sufficient for the turn. No success. His opinion was that 2400m vis at 500' agl was not healthy and that was it.
VMC flight at low level can be safely accomplished within a 4.2nm circling area so you do retain MDA protection; not sure about in a TERPS area...

As for altitudes, it is obvious that 3" per hundred doesn't work: If you're circling at 500ft, you're not going to turn at 15" and if you have any hope of getting wings level by 500ft on final on a 3° slope.
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Old 12th Dec 2013, 00:54
  #80 (permalink)  
 
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Capn Bloggs:


VMC flight at low level can be safely accomplished within a 4.2nm circling area so you do retain MDA protection; not sure about in a TERPS area...

See Post #37 for TERPs. Perhaps in 10-15 years the new TERPS CTL protected airspace will migrate throughout all TERPS IAPs.


In the meantime, 1.7 miles for CAT C and 2.3 miles for CAT D is absurd.
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