Circling Man' Area

[lgw bean flicker]

G'Day All, greetings from the bean,

Just wondered if anyone knew the definition of the Circling Man' Area (ie the area aircraft need to stay in when carrying out a circling approach).

Cant seem to find it anywhere (can anyone provide the info or a reference for me),

Cheers

The Bean

[BOAC]

Tech Log forum Stickies - look up 'ATC' and 1.4.7.1 of ICAO doc 8168 answers your question. Good luck!

[issi noho]

the vis man' area for circling is determined by drawing arcs centred on each runway threshold. the radius of the arcs is related to;

1, ac cat
2, speed for each ac cat
3 wind speed - assumed 25 kt thru the turn
4,bank angle - the lesser of 20 degrees or rate 1

effectively;
cat a max spd 100 radius 1.68
cat b 135 2.66
cat c 180 4.20
cat d 205 5.28
cat e 240 6.94

IN

[dartagnan]

I have not the same numbers!!!here the speed in Nautical miles.


based on 1.3 x VSO= VAT
a 91kts
b 120
c 140
d 165
e 210 Kts

[issi noho]

dtgn

Those are the max Vat that refer to ac cats.

they imply a range of initial and final approach speeds and a max speed for visual circling (and missed app) as above.

best check 8168 to rest your mind.

The max speeds stated do not imply the norm, a circling approach is about alighting the general public safely following an instrument approach to a runway not aligned with a suitable wind for landing. Apply yourself appropriately to the conditions on the day. There are no prizes for doing it right just consequences when it goes wrong.

IN

[Zeffy]

TERPS Circling Areas are MUCH tighter

Originally Posted by issi noho

effectively;
cat a max spd 100 radius 1.68
cat b 135 2.66
cat c 180 4.20
cat d 205 5.28
cat e 240 6.94
IN

Caution: TERPS and PANS-OPS circling areas differ quite significantly.

TERPS circling areas:

• Cat A = 1.3 nm
• Cat B = 1.5 nm
• Cat C = 1.7 nm
• Cat D = 2.3 nm

Jeppesen charts indicate "TERPS" or "PANS-OPS" via a little vertical notation at the lower left edge of the approach chart.

A B767 recently came to grief while circling to land at PUS.
http://aviation-safety.net/database/...0415-0&lang=en

The accident was a horrifically vivid illustration that absolutely zero margin is provided beyond the circling containment area -- the boundaries could well be considered to be vertical walls of concrete.

The B767 hit the mountain while operating at the Cat C circling MDA and only a scant distance beyond the 1.7 mile radius. (Busan is a TERPS airport).

Big red flags should be raised any time a pilot sees circling MDA's increasing with aircraft category.

Also be mindful that the circling containment areas are simply lines drawn on topo maps and do not account for tailwinds. Precise airspeed control is important, but indicated airspeed alone may not provide sufficient protection during conditions of strong surface winds.

Take care,

Z

[Capn Bloggs]

How on earth any airline/operator would allow a Cat C aircraft to circle in the Terps circling area is beyond me. Surely the regulatory authorities would not permit it? PANS OPS 4.2nm is easy, but not 1.7nm...

[issi noho]

quite right I should have acknowledged TERPS

PANS includes a 25 knot increase in TAS due to wind but only in so much as how it affects your radius of turn due to speed not drift.

Like I tried to say before if this is the hardest thing you need to do today apply yourself to it and manage your flight deck to best effect, make real good use of PNF.

[reynoldsno1]

ISTR the B767 at PUS descended to ILS minima for the reciprocal runway before circling for the runway in use (that had no straight-in approach), so was not at circling MDA - I might be wrong, memory is not what it used to be....

Either way, TERPS circling areas are impossible Cat C and above....

[Capn Bloggs]

issi,

if this is the hardest thing you need to do today apply yourself to it and manage your flight deck to best effect, make real good use of PNF.

Quite true. But even more importantly, the company must have clearcut, well researched "circling" SOPs so that their crews don't come unstuck as the 767 crew did. Min WX circling is not difficult when you are trained and practiced and is actually good fun, but if you don't know what you are doing, well ,the statistics speak for themselves. And of course if your PNF is screaming at you to go round, do it!

[issi noho]

ah bloggs

in your co, given the option of keeping runway on PF or PNF side which do you take?

my company has no preferred and, in sim at least, I have watched too many PF's take on too much and let themselves down with handling. This is always a problem as you are in an unfamiliar high drag config.

thankfully, our route structure doesn't put us to the test very often but there are no rigid SOP's in place, mostly because the fleet dept don't want to run a risk of getting it wrong.

[Capn Bloggs]

issi,

in your co, given the option of keeping runway on PF or PNF side which do you take?

No rules about who's side the runway should be on. However is it definitely preferable to have the PF on the runway side. We do have guidance on downwind timing, checklist completion, and quite strict support calls (sink, speed, bank angle). I don't mind being PNF on the "blind side" as I don't have to worry about flying: I can watch everything else and growl if it becomes appropriate. If bloggs in the right seat can't line the jet up with the runway without breaking the rules, no big deal, we'll just make it a tad wider next time. Being PF on the blind side is more difficult but still doable.

[Zeffy]

Originally Posted by reynoldsno1

ISTR the B767 at PUS descended to ILS minima for the reciprocal runway before circling for the runway in use (that had no straight-in approach), so was not at circling MDA - I might be wrong, memory is not what it used to be....

From the Flight Safety Foundation Dec 2005 Accident Prevention, "Boeing 767 Strikes Mountain During Circling Approach":
http://www.flightsafety.org/pubs/ap_2005.html
(Free registration)

“The last data about the status of the aircraft recorded on theFDR showed altitude 704 feet, airspeed 125 knots, groundspeed 133 knots, heading 149 degrees, right bank 26.8 degrees, and pitch angle 11.4 degrees,” the report said.

[emphasis mine]

Cat C circling MDA was 700' MSL; Cat D 1100.

Capn Bloggs - How on earth any airline/operator would allow a Cat C aircraft to circle in the Terps circling area is beyond me. Surely the regulatory authorities would not permit it?

From FAA's AC 120-29A, 4.3.10.11. Circling Approaches:

e. Operators may be authorized to perform circling approaches as published, or may choose not to train flightcrews to accomplish circling maneuvers and accept corresponding high minima limitations regarding circling approaches. If an operator chooses not to train for circling approaches, a 1000 ft HAT DA(H) or MDA(H) and 2 mile visibility limit, or greater, is typically included in OpSpecs to limit use of circling minima for that operator or aircraft type.

f. It is recommended that unless special circumstances exist, wide body (long wingspan) aircraft or aircraft needing to accomplish circling maneuvers at speeds in excess of 165 KTS ground speed should not typically be authorized circling minima below 1000 ft. HAT and 3 miles meteorological visibility.

And so we have the "1000-2 society" for narrow body and the "1000-3 society" for wide body operators, with no (FAA) requirement whatsoever to train crews for circling.

[Capn Bloggs]

Zeffy,

Thanks for that. I think the FAA has lost the plot here. While they impose visibility and altitude limits on operators who choose not to train, the fact that it is impossible to safely fly a Cat C aeroplane within the established norms of flying eg aligned on final by 500ft-ish (1.7nm about) and stay within the circling area of 1.7nm seems to have completely eluded them.

Or are Americans/Terps operators allowed to just ignore the circling area limits if they satisfy those FAA-imposed limitations, in effect doing a Visual Approach?

[GlueBall]

Irrespective of TERPS or PANS-OPS distances and speeds, the Circling Approach is supposed to be a visual maneuver, conducted in VMC. Obviously the 76 at Busan had encountered IMC, in which case the pilots should immediately have discontinued the approach.

[Capn Bloggs]

Glueball,

the Circling Approach is supposed to be a visual maneuver, conducted in VMC

Not so. In Oz, "Visual Circling", as it is called, is not required to be flown in VMC but within the minimums of the chart, normally 4km vis. And given that VMC is only 5000m vis down low, even that is extremely dodgy if you are outside the circling area, which I can only assume you'd be if you were terpsing it. If there is a mountain just outside the 1.7nm circling area and it suddenly comes into view on the nose, you're probably going to go very very close to it, especially if you are looking over your (or the FOs) shoulder for the runway.

[Zeffy]

What's wrong with this picture?

Originally Posted by Capn Bloggs

...Or are Americans/Terps operators allowed to just ignore the circling area limits if they satisfy those FAA-imposed limitations, in effect doing a Visual Approach?

That seems to be the underlying philosophy, Capn.

It appears that the airlines and FAA have convinced themselves that if the destination wx is 1000-2 or -3, the crews won't be performing an IFR circling maneuver, they'll simply be flying a visual approach -- therefore, no training $$$ required.

As you've noted, several elements of the plot have been missed.

Most significant to me is the fact that many circling MDA's are relatively high. At an airport like this
http://www.naco.faa.gov/d-tpp/0612/00652IL11.PDF
the Cat C HAA is 710-ft; the Cat D is 990-ft. And it's certainly not hard to find airports with circling HAA's much higher than these.

So it entirely possible that card-carrying members of the 1000-3 society could find themselves facing a circling approach in minimum weather -- a scant 300 feet above the obstacles -- with zero training and practice.

Many of my corporate-pilot peers have been drinking the same Kool-aid -- emulating our air carrier standards.

"...We won't circle unless the weather is 1000-3".

Well, OK -- so what do you do at mountain canyon airports with HAA's over 1500'?

"Oh, if the HAA is higher than 1000 feet, we'll fly the published MDA".

So, at airports located on billiard-table landscapes, they'll be maneuvering at close to traffic pattern altitudes with comfortable obstacle clearance margins.

But in obstacle-rich environments, they'll be struggling to keep the beast within the TERPS maneuvering area... flying only 300 feet above the obstacles... probably oblivious to the magnification of cold temperature effects on baro-altimeters with increasing height above the station...

[Zeffy]

Originally Posted by On the Straight and Level

...How would you be alerted to the fact that the circling minima is based on TERPS? Is it simply a case that if you using Aerad booklets then minima and radius WILL be predicated on Pans-Ops?

I'm not an Aerad subscriber, but if the max circling speeds are shown on the chart, they should reflect TERPS or PANS-OPS.

TERPS Max Speeds:
A = 90
B = 120
C = 140
D = 165

issi noho already posted the PANS-OPS speeds.

If the lower values above are depicted, the procedure was drawn to TERPS.

Hope that helps.

[issi noho]

From the thales terminal chart legend - aerad

minima charts - minima conform to jar-ops 1 or 3, as approp

further

minima for US are for public transport aeroplanes based on FAA regulations and conform to UK jar ops 1 criteria.

for circling or cloud break procedures minimas are quoted as MDA of HAA (height above ad)

..

Jar ops 1 says nothing about the criteria on which the procedure was drawn, but dictates that you must stay within the prescribed area.

UK caa issued FODCOM 13/2003 which mandates that UK operators should provide information to crews regarding the differences between the 2 systems and information to determine how the minima is generated.

The answer to the question is

In the AERAD grey supplement pages AER48/49 is a table by country which determines the criteria (TERPS or PANS) for approach design

IN

[Capn Bloggs]

Our Oz Jepp approach charts have, on the side of each chart, "PANS OPS 4".