Circle to land minimas

[Valmont]

Hi,

Yesterday, i had a discussion with a captain and we would not agree on the circle to land minimas.

He was convinced that the circle to land minimas were linked to the runway we would land on. i.e. we were shooting the ILS 06 circle to land 24 and he pulled out the VOR 24 app plate to read the circle to land minimas.
And his point was that next to the circle to land minimas for each approach, it's written: Circling height based on rwy XX threshold elev of XXXX ft.
For example, for the ILS 06 circling minimas: based on rwy 06 threshold elev of XXX. Remplace ILS 06 and rwy 06 by VOR 24/rwy 24.

But it makes no sense to me, the circling minimas are linked to the approach we are shooting initially. So i'd read the minimums straight out of the original approach plate (i.e. ILS 06 in this case).

At the end, it didn't make any difference since the circling minimas
were exactly the same. (which i do understand why)


I looked up on the Jepp Away Manual and i couldn't find anything, does anyone have references to help me figure it out ?

Thanks

[BOAC]

Circling minima are not runway specific. Just occasionally they can be sector specific but it is very rare. Both PANSOPS and TERPS CMs are derived from an area constructed AROUND THE RUNWAYS and since while circling you effectively fly through the 'R06' area and the 'R24 area' and any other runway area................he is wildly wrong However, as you say, since the CM for 06 and 24 will be exactly the same, why not just say "Yes Captain" and use the value printed?

[galaxy flyer]

This is pretty basic....he's a Captain? :confused:

GF

[Valmont]

galaxy flyer, he's even a TRI and TRE. Flew for major airlines all kind of a/c from DC8 to 747 and has been an A330 SFI for a couple years for Airbus. Even flew the pope.. he got kind of a big ego.

I'm tired of the "Yes captain" sentence with this dude, just wanted to make a point.. I'd really like some reference

[aterpster]

Most countries expect you to use the circling minimums specified for the approach you are using, but a few countries in fact refer you to a different IAP chart for circling minimums. Unless a chart makes that reference, though, it would be a technical violation to use the minimums from a different chart. But, there is no practical impact.

[Natstrackalpha]

I'm tired of the "Yes captain" sentence with this dude, just wanted to make a point.. I'd really like some reference

Notwithstanding CRM - talk about change rosta or change job.

[Valmont]

Exactly what i just did. Called the chief pilot, problem solved.

[Rick777]

In the US you use the minimums published for the approach you are flying. This is pretty basic. It was even a question asked when I interviewed with the US major airline that I retired from. I don't know how the pope does it though.

[Check Airman]

The CA was wrong. Circling minima apply for all runways unless otherwise noted. I suppose some states vary, as shown on this thread.

The Jepp chart ref states that the circling MDH is based on the airport elevation, not the runway elevation. That's further proof that the circling minima wasn't developed with a specific runway in mind.

I wouldn't crucify the guy though, even if he's a training CA. He IS human right...?

[BOAC]

even if he's a training CA. He IS human right - Hmm - I have known the 'odd' exception to that rule:)

[BOAC]

Valmont - if you are still around - which chart producer are you using?

[roulishollandais]

Even flew thepope..hegot kind of a big ego.

I'm tired of the "Yes captain" sentence with this dude, just wanted to make a point..
In flight you have to obey to the Captain:oh::E:mad:

[RAT 5]

I wouldn't crucify the guy though, even if he's a training CA. He IS human right...?

What's the difference between God & a Training Captain? God doesn't think he's a training captain.


In flight you have to obey to the Captain

Ouch! What happened to CRM, advocacy and CREW concept? I hope your tongue was firmly in your cheek.

"we're about the crash captain." "No we're not; keep going." "We're about to crash captain." "No we're not; keep.........oh f@£k. Wrong again."

Was it not a DC-10 crashing in MAD where the last words from the Captain when he cancelled the GPWS were, "shut up gringo."

[aterpster]

Check Airman:



The Jepp chart ref states that the circling MDH is based on the airport elevation, not the runway elevation. That's further proof that the circling minima wasn't developed with a specific runway in mind.

You might want to reconsider that:

http://i201.photobucket.com/albums/aa214/aterpster/MRY-1_zpsddcbe331.jpg

http://i201.photobucket.com/albums/aa214/aterpster/MRY-2_zps0f380969.jpg

[BOAC]

You might want to reconsider that: - we have. Circling minima cannot be lower than the minima for the approach flown. Since this is referenced to threshold elevation, that is what cm will be based on where the VOR minima is higher than the 'basic' circling minima.

Verdict - red herring!:) Not applicable to the OP's OQ.

[aterpster]

BOAC:

I was responding to Check Airman's post, not the OP.

[de facto]

Circle to land minimas

one minimum, two minima:E

[BOAC]

.......and I was responding to yours, and I suspect Check Airman probably knows what I posted anyway - and he WAS responding to the OP. The point I was making is that your 'example' does not disprove the point that CA and Jepp state. It is obvious that the cm is NOT 1660' at MRY, (based on whatever) but HAS to be published as that based on TE because of the 'rules' - it is 'artificial'. There is nothing to stop you circling at 900 QNH off a visual on 28L.

[BOAC]

So why is there no CM for the 19 plate? 8240 would not seem unreasonable.

[OK465]

I suspect that since they've also got an ILS to 01, as well as an NDB to 01 in addition to the LNAV or WAAS 01 procedure, there would just be no sensible reason to circle from a 19 WAAS procedure to get into 01.

edit: The only approach to 19 is the WAAS/LPV however, so if you're not WAAS equipped, the only other way into 19 is to circle.

Above my pay grade however and only offered as a comment on said Captain's aviation savvy. I wonder which missed approach he would chose to fly? :eek:

It is odd though and maybe it's the only example like that...

[BOAC]

"I wonder which missed approach he would chose to fly?" - yes, that would be interesting, but of course - he is a TRE/I...............:)

[aterpster]

BOAC:

So why is there no CM for the 19 plate? 8240 would not seem unreasonable.

Current FAA policy is to not publish CTL minima on an approach with vertical guidance and only a DA. I would like to see "with precision minimums only" because that has more clarity, but LPV does not yet have the ICAO stamp of approval to be classified as precision.

[OK465]

Actually the strange thing here is that there is NOT an LNAV line of minima on the 19 procedure? Then the Captain could have his opposite direction circling mins...which might even be higher like KMRY. :}

Have you ever seen any other RNAV (GPS) with only an LPV line of minima?

[galaxy flyer]

Speaking of the miss, ask said TRI what would happen in the FMS when he pressed TOGA circling around to the opposite runway.

GF

[Valmont]

I had to fly one other rotation with this dude, you would'nt believe what he did to me today... I think the think the CP wont like what i'll have to say.

BOAC, we're using Jepp.

With the Yellowstone example, i would'nt try a RWY 19 approach circle to land 01 as it doesn't seem to be an option looking at the plate.

GF, he'll tell me that he'd rejoin the initial MA procedure, we already talked about it.

Aterpster, BOAC got a point. Thanks for giving examples though, we got a good discussion going on ;).

[bubbers44]

Circle to land minimums are on the approach plate you are using. Sometimes it says which way you have to circle but that is all you care about. Do not ever look at other approach charts, use the approach you are doing because it is all there. Keep it simple because that is why you only need one approach chart.

[16024]

I would'nt try a RWY 19 approach circle to land 01
And neither would I!
I'm not familiar with that field, but looking at the terrain I think circling off the 19 approach could lead to a world of pain.
There's probably a good reason a circling approach isn't published, and the trainer of the OP needs to think very carefully before going off piste.

[BOAC]

Thanks Valmont - I have never seen that 'comment' on a Jepp plate. Can you tell me which which approach please?

What is this issue with circling off 19? If there were minima published (and it would probably be 8240 - but missing as Aterp explained) there should be no 'terrain' issue at all. This shows a basic misunderstanding of what a circling area is.

Aterp - how far away is recognition of LPV in ICAO? As OK says, why no LNAV for 19? Mind you, we may not have seen all the plates?

[aterpster]

BOAC:

What is this issue with circling off 19? If there were minima published (and it would probably be 8240 - but missing as Aterp explained) there should be no 'terrain' issue at all. This shows a basic misunderstanding of what a circling area is.

There is no issue with publishing CTL on the LPV 19. The issue is FAA policy. They used to publish CTL on an IAP with precision-only minimums, or Decision Altitude only, if you will. They changed the policy some three or four years ago. There apparently is an obstacle or obstacles that interfere with a 3-degree gradient LNAV path and a 3-degree VNAV path. LPV uses far different containment areas; basically ILS criteria with their "troughs."

How far away is recognition of LPV in ICAO? As OK says, why no LNAV for 19? Mind you, we may not have seen all the plates?
No idea about ICAO on this.

As to LNAV it may have worked with a steeper descent gradient but that would require a second IAP (Y and Z), which the FAA presumably didn't want to do at this location. Or some obstacle to the left or right of the ILS/LPV lateral areas caused LNAV too steep to meet criteria. Can't tell without the FAA work records.

[BOAC]

There is no issue with publishing CTL on the LPV 19 - we have moved on from that - you explained why earlier. The issue is about flying a CTL off 19 - see posts #26 and #28 where I assume posters are concerned about the 'terrain' which indicates a possible lack of understanding of the principle behind CTL areas under both TERPS and PANSOPS.

[roulishollandais]

Legitime autority of the Captain still exists
I wouldn't crucify the guy though, even if he's a training CA. He IS human right...?

What's the difference between God & a Training Captain? God doesn't think he's a training captain.

In flight you have to obey to the Captain

Ouch! What happened to CRM, advocacy and CREW concept? I hope your tongue was firmly in your cheek.

"we're about the crash captain." "No we're not; keep going." "We're about to crash captain." "No we're not; keep.........oh f@ £k. Wrong again."

Was it not a DC-10 crashing in MAD where the last words from the Captain when he cancelled the GPWS were, "shut up gringo."
OPS 1.090 Autorité du commandant de bord
L'exploitant prend toutes les mesures raisonnables nécessaires afin de s'assurer que toutes les personnes transportées à bord de l'avion obéissent à tous les ordres licites
donnés par lecommandant de bord dans le but d'assurer la sécurité de l'avion et des personnes ou des biens qui s'y trouvent.

[aterpster]

BOAC:

- we have moved on from that - you explained why earlier. The issue is about flying a CTL off 19 - see posts #26 and #28 where I assume posters are concerned about the 'terrain' which indicates a possible lack of understanding of the principle behind CTL areas under both TERPS and PANSOPS.

Under FAR 97, no one can circle to land off the LPV 19 IAP. The can request clearance from ATC for a contact approach if their ops specs permit contact approaches, or they can request a visual approach if the weather conditions are sufficient for a visual approach. In either case the pilot would assume sole responsibility for terrain clearance. Or, if the weather is sufficient, they can cancel IFR and do whatever they feel is safe to land on other than Runway 19.

[BOAC]

I take it you have not read #26 and #28. I'll say again - we understand " no one can circle to land off the LPV 19 IAP"...........

[FlightPathOBN]

OT...from that plate, circle to land CAT D into WYS !?!? :eek:

With RNP procedures, I have never put circling on a plate, anywhere in the world...

http://flightaware.com/resources/airport/SCC/IAP/RNAV+(RNP)+Z+RWY+23/png/1

[OK465]

To further muddy the water.....

As to LNAV it may have worked with a steeper descent gradient but that would require a second IAP (Y and Z), which the FAA presumably didn't want to do at this location. Or some obstacle to the left or right of the ILS/LPV lateral areas caused LNAV too steep to meet criteria.

Here's an example of a runway (KRIL 26) with separate plates for an LNAV procedure (with CTL) and the separate WAAS LPV. Of note, the descent gradient for the LPV (3.60) is steeper than the gradient for the LNAV (3.58).

No one size fits all in them thar hills....:)

http://155.178.201.160/d-tpp/1305/06741RW26.PDF

http://155.178.201.160/d-tpp/1305/06741RX26.PDF

(Once again, the LPV to WYS 19 is the ONLY IAP to 19, no LNAV. I think this is probably somewhat unique to find a runway ONLY served by an LPV line of minima, nothing else. I'm also wondering then why 19 couldn't be served with an LP line of minima with CTL which might have to be higher than 8240 as a result of the LP approach mins possibly being higher than 8240 on that end?...once again creating a problem for said Captain)

[felixthecat]

No need to overcomplicate things …ILS 06 Circle 24 …. Use the circling minima on ILS 06 plate and incase of missed approach turn shortest distance towards the missed approach for the instrument landing runway…in this case ILS 06 missed approach.

[aterpster]

BOAC:

I take it you have not read #26 and #28. I'll say again - we understand " no one can circle to land off the LPV 19 IAP"...........

Who are you addressing?

[aterpster]

FltPath:

With RNP procedures, I have never put circling on a plate, anywhere in the world...

That implies you have a choice. You don't.

[BOAC]

Who are you addressing? - er, you?

[aterpster]

BOAC:

You got me confused. I thought I was being responsive. Then again, I'm an old guy.

:ooh:

[Valmont]

BOAC, Check your private messages.

[PantLoad]

Valmont,

Please tell me this guy was not U.S. trained. Please tell me....


Fly safe,


PantLoad

[RAT 5]

Legitimate autority of the Captain still exists

Roulishollandais: In general, yes, but there's not legitimate authority to command and force you to do the wrong thing, especially crash the a/c. "I was only obeying orders." is not a defence. Are you suggesting that a captain has the authority to force an F/O to disobey SOP's or execute bad airmanship in an unsafe manner; or to do so himself without being opposed?

[16024]

Spot on, with the caveat that the SOP's themselves probably say something along the lines of "The captain may take any action...blah,blah...safety".
Mine do.
And the captain disappearing into the boonies muttering about PANS CTL areas having nothing to do with terrain would be one such discussion point, if I were RHS (or jumpseat).

[BOAC]

Here are 2 questions for those who understand circling:

Would you, unlike some here, circle off 19 at the meteor crater if there were published minima?

Is this ONE occasion where you could be justified in looking at the 01 plate to extract CTL minima?

SUPPLEMENTARY: What if joe-driver decided to fly the LPV 01 to a CTL at 8240'?

[OK465]

Just when you thought it was safe to relax....

Said Captain is flying a Category C aircraft to scenic Lewiston, and planning to fly the RNAV (GPS) RWY 26 with the intent of circling to RWY 08. He notes the 26 LNAV MDA is 4480 and Category C circling minimum is 4720.

http://155.178.201.160/d-tpp/1305/00231R26.PDF

“Okay kid, for today’s lesson get out the RNAV (GPS) RWY 08 plate and we’ll use those minima to circle.”

Kid notes that the LNAV MDA is 4520 and Category C circling minimum is 4780, higher than the 26 plate. Kid points this out to the Captain.

http://155.178.201.160/d-tpp/1305/00231R8.PDF

“Okay kid, then get out the VOR RWY 08 plate and let’s take a look.”

Kid points out that the Category C S-8 VOR minimum is 4600 but Category C circling minimum is 4660, lower than the 26 plate.

http://155.178.201.160/d-tpp/1305/00231V8.PDF

Kid points out that there are no other IAPS to KLWT.

Captain scratches his head…ponders 4660, 4720 & 4780. ”Okay :mad: it kid, we’ll just fly the LPV straight-in to 08 and do some more circling training tomorrow.

[BOAC]

My main breaker has tripped. What are they doing?

[galaxy flyer]

OK465

I gotta ask, did you just happen upon KLWT or do you use for some mind-bending treatment of new IR students?

GF

[BOAC]

Perhaps Valmont's Captain moonlights for the FAA?

[OK465]

GF

I gotta ask, did you just happen upon KLWT or do you use for some mind-bending treatment of new IR students?

I was looking for somewhere nice to go on honeymoon with my new 24 year old bride.

[BOAC]

I'd suggest a straight-in rather than a circle.......................:)

[galaxy flyer]

And you, at 68, makes proud to be an American.

GF

[FlightPathOBN]

shes 24 and you choose Lewiston? :rolleyes:

ZLV baby...ZLV... :ok:

[aterpster]

OKC465:

So, why does the guy try to violate Part 97 rather than simply getting a clearance for the Runway 8 procedure?

[aterpster]

FltPathOPN:

She is an avid hunter and fishergirl.

The mountains around Lewiston are stunning.

[PappyJ]

Going back to the beginning of this thread, I suggest that the 'captain' in question was confused over the difference between a 'cirlcing' manuever and a 'side-step.'

Circling is simple -

It is common to fly to an airport where there is, let's say, an ILS approach but only to one runway. Suppose the winds don't favor that runway on this particular day. What to do? How about flying the ILS down to circling minimums, then circle to land on the opposite runway.

Just about every training manual, AIP, etc will state something to the effect of "...decend to the circling minimums on the profile view of the approach in use..."

Nowhere is it ever suggested to use the minimums for an approach that you DID NOT fly!

Whereas,

Sidestep Maneuver -

ATC may authorize a side-step maneuver to either one of two parallel runways .... followed by a straight-in landing on the adjacent runway. Aircraft executing a side-step maneuver will be cleared for a specified nonprecision approach and landing on the adjacent parallel runway.

For example, "Cleared ILS runway 7 left approach, side-step to runway 7 right." Pilots are expected to commence the side-step maneuver as soon as possible after the runway or runway environment is in sight. Landing minimums to the adjacent runway will be based on nonprecision criteria for the approach and therefore higher than the precision minimums to the primary runway, but will normally be lower than the published circling minimums.

Gotta say it; I agree with Pantload on this one.

[aterpster]

Related to this thread, the FAA is finally implementing PANS-OPs-like circle to land areas. It will likely take 6, or more, years for this to factor through all the FAA IAPs:

http://ww1.jeppesen.com/documents/aviation/notices-alerts/bulletins/Briefing_Bulletin_JEP_13-A_TERPS_Chg_21.pdf

The first such IAPs were published on May 2.

[aterpster]

OK465:

I was looking for somewhere nice to go on honeymoon with my new 24 year old bride.

My bad. I was thinking of Livingston, just east of Bozeman.

[roulishollandais]

@RAT 5
I had to fly oneother rotation with this dude, you would'nt believe what he did to me today... I think the think the CP wont like what i'll have to say.
I don't contest the F/O has to be able to say NO in some cases (ie Flight KE801 GUAM 1997). But then HE will have to prove the Captain asked him to do something illicit or countrary to air safety. The Captain according to the Law does not need to prove he was right...

The result is in conflictual relation increasing flight after flight, and probably problems with the CP who will surely prefer to defend the Captain.
No doubt that Valmont told that storry to get help from us not to circle, but to manage relation improvement with "this Dude" and the "CP" and his future in the Airline.
But most Captains have learnt from experience and "do it simple".

[BOAC]

I would like (reluctantly:O) to return from 24 yr old brides and what to do with them to circling minima and in particular post #47.

These figures contradict everything I have ever understood or been taught about circling. Can anyone who understands this US system explain the varying altitudes?

[aterpster]

BOAC:

These figures contradict everything I have ever understood or been taught about circling. Can anyone who understands this US system explain the varying altitudes?

I believe that's about TAS increasing with the elevation of the airport.

But, here are the three pages of FAA TERPs criteria for your assessment:

http://tinyurl.com/celrhbp (http://tinyurl.com/celrhbp)

[BOAC]

Thanks for the drop, but that doesn't really answer the question - and the 'airport elevation' does not change!

The only (drop) bit (Section 6 - 260 I cannot follow is
"and the evaluation of the final segment delivering the aircraft to the circling area. Also see Vol. 1, chapter 3, paragraph 3.2.1b." whatever that means - that is the only factor I can see that might produce different numbers - but does not at all other airports we know of.

Is there anyone around who produces charts who can have a crack at this puzzle?

[aterpster]

BOAC:

A link to the entire order:

http://www.faa.gov/documentLibrary/media/Order/8260.3B_Chgs_1-25.pdf

[FlightPathOBN]

terpster,

The FAA madness continues.... Change 26 (http://www.faa.gov/about/office_org/headquarters_offices/avs/offices/afs/afs400/afs420/policies_guidance/draft_directives/media/8260.3B_CHG26_Formal%20review.pdf)

perhaps someday, they will make the entire 8260 digital, not photocopied, so it can be searched....

OT... years ago, I saw a draft 8260.52A, that was supposed to align .52 with ICAO...have you seen that around somewhere and who might be working on it, if anyone??

[BOAC]

FPOBN - I take it you have no explanation for the 3 different CMs?

[swh]

BOAC,

It might have to do with

"5.4.4 OCA/H for visual manoeuvring (circling)
The OCA/H for visual manoeuvring (circling) shall provide the minimum obstacle clearance (MOC) over the highest obstacle in the visual manoeuvring (circling) area as specified in Table I-4-7-3 of Chapter 7. It shall also be:
a) above the lower limits (also specified in Table I-4-7-3); and
b) not less than the OCA/H calculated for the instrument approach procedure which leads to the circling manoeuvre. See Chapter 7, “ Visual manoeuvring (circling) area”."

With the different approaches they have different "OCA/H calculated for the instrument approach procedure which leads to the circling manoeuvre" because of the different splays due to the accuracy of each approach design final segments.

[BOAC]

swh - we looked at that in post#15 for Monterey. I don't see the approach minima being the restriction on these approaches from post #47?

[galaxy flyer]

A nymphomaniac who is turned on by Oklahomans that post on Pprune, I'll bet.

GF

[felixthecat]

I know its a bit radical and out left field but hey why not just round up the highest to the next 100' i.e. 4800 and fly that? I am an old simple pilot and believe in the KISS principle …. Keep It Simple Stupid. You only have so many heartbeats don't use them up so fast.

[BOAC]

Careful, OK - you'll get Slasher here PDQ with those sort of posts.....................:)

Back to the CTL - it is interesting that 2 of the 3 CMs breach EU-OPS minimum MDH for Cat C circling (600').

I think all we can assume is that someone might have been a bit too far into the Jack Daniels when the charts were drawn?

How will one distinguish the 'revised' (PANSOPS) CM from the 'old' (TERPS) CM on an FAA chart?

[RAT 5]

In flight you have to obey to the Captain

Harping back on this topic in the thread I would draw people's attention to the thread on the Bali B737 crash. It would seem the captain followed my earlier scenario of "keep going.......oops, wrong again."

What happened to F/O's having a self preservation button somewhere in the area of the TOGA button; or at least a loud voice?

[galaxy flyer]

What happened to F/O's having a self preservation button somewhere in the area of the TOGA button; or at least a loud voice?

One guess, dirigisme, French for "I have control"

GF

[aterpster]

BOAC:

Back to the CTL - it is interesting that 2 of the 3 CMs breach EU-OPS minimum MDH for Cat C circling (600').

FAA uses TERPs and only TERPs.

I think all we can assume is that someone might have been a bit too far into the Jack Daniels when the charts were drawn?

I don't assume that so please don't speak on my behalf.

How will one distinguish the 'revised' (PANSOPS) CM from the 'old' (TERPS) CM on an FAA chart?

Different speeds as it always has been.

[FlightPathOBN]

Pilots should be aware that there are significant differences in obstacle clearance criteria between procedures designed in accordance with ICAO PANS-OPS and US TERPS. This is especially true in respect of Circling Approaches where the assumed radius of turn and minimum obstacle clearance are markedly different

From May 2, 2013, the FAA started publishing new instrument approach plates that include an enlarged segment of airspace to protect aircraft during circling approaches. The new airspace also offers pilots additional obstacle clearance while considering their MSL altitude above the MDA, which affects true airspeed. The boundaries of protected airspace for circling approaches are defined by arcs drawn from the threshold of each runway at an airport. The larger the aircraft, the larger the arc. Previous versions of the FAA’s terminal instrument procedures (Terps) used a radius of 1.7 nm from the end of the runway for a Category C aircraft such as a Hawker 800. Under the new criteria that radius will increase by 65 percent, to 2.7 nm. Chart providers U.S. Terminal Procedures and Jeppesen both plan to use new chart symbology to identify the updated approaches. The government plates will show an inverse “C” in a black box in the approach minimums area of the plate, while Jeppesen will use a “C” inside a black diamond. Charts without the new designation will continue to be guided by the old, smaller-radii criteria.

Jepp Charts:
http://www.skybrary.aero/images/JepAC.jpg

edit: Govt Charts
http://www.nbaa.org/ops/airspace/issues/_images/us-government-circling-minima-chart.jpg

Circling Approach - difference between ICAO PANS-OPS and US TERPS (http://www.skybrary.aero/index.php/Circling_Approach_-_difference_between_ICAO_PANS-OPS_and_US_TERPS)

[BOAC]

"The government plates will show an inverse “C” in a black box in the approach minimums area of the plate,". Thanks FPOBN

The TERPS/PANSOPS thing has been done to death here so many times it really does not need doing again! I was hoping our 'charters' here might be able to offer an explanation for the 3 different circling minima, but it appears they are flummoxed too.

Let's try a really simple question for someone:
Is it safe at Lewiston to fly the VOR 08 to circle at 4660' which is 120' lower than the safe circling from an LNAV approach to 08 and lower than the circle from the 26 approach - and why? I thought circling areas were fixed in geometry on airfield/runway characteristics so should not change, (barring approach minima issues, but here both less than 4660'). Presumably the circling area must change, but why?

[FlightPathOBN]

The geometry is not fixed, it varies with altitude and aircraft CAT...

http://operationsbasednavigation.com/wordpress/wp-content/uploads/2013/05/ScreenHunter_45-May.-17-08.51.jpg

CAT A and CAT B are close, so they can have one circling MDA, while CAT C is much larger, and CAT D even larger differences in radii....

edit:
Here is the proposed change to the charts on the CAT Radius.

http://operationsbasednavigation.com/wordpress/wp-content/uploads/2013/05/ScreenHunter_45-May.-17-09.09-e1368807195401.jpg


RNP charts dont have to deal with this! :E

[BOAC]

The geometry is not fixed, it varies with altitude and aircraft CAT... - Lewiston - same airfield elevation, Cat C same Category??

I'll try it more simply - can circling area geometry vary for the same airport and same aircraft cat - and how?

EDIT:RNP charts dont have to deal with this! - why? Is circling abandoned with RNP charts?

EDIT 2: Shouldn't the Cat C and D be 3 and 4nm?

[FlightPathOBN]

same airfield elevation, Cat C same Category

not airfield elevation...MDA of circling.

[BOAC]

We are going around in circles here! :) Original question - how can you have 3 different CMs for the same airfield, same a/c Cat?

Q1- can circling area geometry vary for the same airport and same aircraft cat - and how?

a) I assume you take the obstacles within the altitude adjusted radius and add 300'?
b) If this pushes the CM into the next altitude band, you redo it at the new radius and iterate if required?

There we are - 1 CM surely?

Q2 - RNP/CTL?

[FlightPathOBN]

EDIT 2: Shouldn't the Cat C and D be 3 and 4nm?

Good comment, add it to living with the FAA....

RNP are coded procedures, there is no circling...you are on it or not.


I dont know why there are the differences at Lewiston, and I really dont want to get into laying out the circling diagram...but I will leave you with this figure 2 to ponder, consider the different variables, (and really be concerned about how many mistakes can be found on charts or in the navdatabase)

http://operationsbasednavigation.com/wordpress/wp-content/uploads/2013/05/ScreenHunter_45-May.-17-11.47.jpg

[BOAC]

Seen that one, thanks, and it doesn't help, but as you say "and really be concerned about how many mistakes can be found on charts or in the navdatabase" - cue Jack Daniels...................?

Pleased I will never operate there. As with all things aviation we must take the safest (highest) value, but one might not be aware there is a 'higher'.

[FlightPathOBN]

Well, not Jack, but....

anything to get the nightmares to stop!

trust me, every 56 days, when you get the navdatabase files prior to publish to validate...you would be very, very surprised just how many waypoints and runway ends dont concur between design, AIP, and even the different navdatabase providers.....before it is sent to the airline, you have to tell them which one to use. (sometimes the navdata providers will fix the database, sometimes not)

The FAA standard for survey really kills me, as the lat/long for the runway end is measured at the edge of pavement, not the threshold, so the TCH is a real problem. Try looking up a few runway endpoint locations in the FAA database, and plotting them on Google Earth...

[FlightPathOBN]

Here is an example that I am well aware of...

Where are you gonna land if you follow the navdatabase?

https://nfdc.faa.gov/nfdcApps/airportLookup/airportDisplay.jsp?category=nasr&airportId=scc

http://operationsbasednavigation.com/wordpress/wp-content/uploads/2013/05/ScreenHunter_45-May.-17-12.46-e1368820165737.jpg

http://operationsbasednavigation.com/wordpress/wp-content/uploads/2013/05/ScreenHunter_46-May.-17-12.46.jpg

[BOAC]

Gulp! PRNAV/WASS/GPS, call it what you will and..............................

[FlightPathOBN]

It not just PRNAV/WASS/GPS, when you punch in the runway in the FMS, this is what it is looking at....and what is used for the NOTAM review! :mad:

I wont bore you with anymore, but here is 13R at PSP...

http://operationsbasednavigation.com/wordpress/wp-content/uploads/2013/05/ScreenHunter_46-May.-17-13.51.jpg

[PappyJ]

There is something more to this one also. and they are based on 'True Polar Tracks'.

[FlightPathOBN]

OK,

Tricks, really? With the magvar, the RWY change regularly...it is now 6/24, not 5/23..

You either need glasses, or well...

Didnt you notice the X's? Did you notice the construction equipment grinding up the runway?

http://operationsbasednavigation.com/wordpress/wp-content/uploads/2013/05/ScreenHunter_47-May.-17-15.59.jpg

Aside from that, the FAA NFDC portal, which is the Official data source, shows the runway end in the wrong location, just as in the PSP example...you really dont want to see more examples do you?

[FlightPathOBN]

And yes, I wear glasses.

Well, then you are just stopid.

Here is the FAA database (look in the upper right hand of the page for effective dates...)
https://nfdc.faa.gov/nfdcApps/airportLookup/airportDisplay.jsp?category=nasr&airportId=scc

In the Official database, do you even see a runway 6?
Looks like the runway has been built, and there are a few procedures for it, so why is it not in the NFDC database? What would be your GUESS as to the coordinates of the threshold?

I suppose the PSP example was another trick?

I have been talking about RNP procedures...

Here is the RNP plate for RWY 05, notice the active dates?

http://operationsbasednavigation.com/wordpress/wp-content/uploads/2013/05/ScreenHunter_48-May.-17-16.31.jpg

[DownIn3Green]

Valmont,

I don't fly anymore but I know I have flown with you, or your clone of a wanna be pilot...

CRM is Great, I endorse it, but the cockpit is not a democracy...Only ONE PERSON'S decision matters in the final analogy....and that person is NOT YOU!!!

For you to refer to your CAPTAIN as "That Dude" marks you as a frigging jerk in the very first instance...

You're Profile? Commercial Pilot? At FL510? You're either a dreamer or a bigger a$$hole than you have portrayed yourself as on this thread...

Let me know who you work for, and who this "Dude" is, and I'll call your Chief Pilot with a printout of your comments, and then it definately will be "PROBLEM SOLVED" for you, the "Dude", and the next sorry "Dude" who is unfortunate to be desperate enough to have you show up in his right (CO-PILOT) seat...Bl@w Me...Send me a PM and I'll give you my phone #...I don't hide behind PPrune...DI3G:ugh::ugh::ugh::ugh::ugh:

[Capn Bloggs]

The new Cat C distances are still too small for comfort...

[DownIn3Green]

Arpster, Galaxy, BOAC and others...

We all have been on this site for years...we all have years and many hours behind us...(myself, I am 46 hrs short of the golden # 10,000, and will never see it)...We don't always agree, but as Captains we have never, ever called each other "DUDE"...

Valent has stirred a hornet's nest...He obvivoulsy has zero to very little experience...Reporting his "DUDE" to the Chief Pilot for something that probably scared the sh!t out of him? And you are feeding him by discussing the fine points of something that probably never happened?

With extensive experience in Africa (Transafrik, Cameroon Airlines, Trans Air Congo and SAFIR), even though I was born and bred in the USA/FAA...I feel I have seen it all and I have had pissants like Valent imposed on me...

Please don't give him his due, send him packing to FL510 and let's keep the Prune for real pilots...DI3G:ugh::ugh::ugh::ugh::ugh::eek::eek::eek:

[bubbers44]

You only need one approach plate. Just use it and not make it complicated.

[aterpster]

FligtPath:

Aside from that, the FAA NFDC portal, which is the Official data source, shows the runway end in the wrong location, just as in the PSP example...you really dont want to see more examples do you?

We use the FAA ANV datasheets website for all such stuff, not the NFDC website.

[BOAC]

And you are feeding him by discussing the fine points of something that probably never happened? - I was under the impression that Valmont has left this thread (12 May) now that we have moved on, and I am just trying to 'discuss' OK's "3 CM" example, the system and calculations, and which is 'dominant', and so far not one procedures 'expert' has managed to explain them - which is concerning since pilots may well be eroding safety margins with the lower values.

[aterpster]

BOAC:

- I was under the impression that Valmont has left this thread (12 May) now that we have moved on, and I am just trying to 'discuss' OK's "3 CM" example, the system and calculations, and which is 'dominant', and so far not one procedures 'expert' has managed to explain them - which is concerning since pilots may well be eroding safety margins with the lower values.

'expert' in quotes means you mostly hold in contempt whatever I present in this forum. That gets old really fast. OTOH, you seem to lack a grasp of the technical issues so I recommend you email the terminal procedures designers directly at the FAA for pilot expert to procedures expert dialogue:

[email protected]

They are indeed the experts on FAA procedures. Let us know what you find out.

[BOAC]

Aterpster - incorrect - surely you have been around here long enough to know that the 'qualifications' quoted are not always true or accurate, hence as with any undefined value I place ' ' around the word expert. whatever I present in this forum whereas on other threads your inputs have been helpful, in relation to this thread most of your replies to me have regrettably not addressed the questions I have asked or apparently referred to the links I post eg introducing 'TAS' which was not relevant. I had hoped that having two people 'involved' (if you prefer) in airport procedures under TERPS we would be able to come up with some sort of explanation for what is potentially a dangerous set of figures under TERPS and it is of concern that we cannot. you seem to lack a grasp of the technical issues - as do others - which is why I have asked here so that those 'involved' in the subject might educate me but it appears they do not have a 'grasp' either. I will, given time, contact that address. Whether they will
a) answer
or
b) know the 'right' answer, especially when they appear to have 'erred' on FPOBN's circling radius example

I am not sure. If and when, however, I will advise the answer here.

[aterpster]

BOAC:

whereas on other threads your inputs have been helpful, in relation to this thread most of your replies to me have regrettably not addressed the questions I have asked or apparently referred to the links I post eg introducing 'TAS' which was not relevant. I had hoped that having two people 'involved' (if you prefer) in airport procedures under TERPS we would be able to come up with some sort of explanation for what is potentially a dangerous set of figures under TERPS and it is of concern that we cannot.

Let's start over. Where are the potentially dangerous set of figures? I'm not going back through the thread to try to find the "potentially dangerous set of figures."

[BOAC]

No thanks.

[aterpster]

BOAC:



No thanks.

You are consistent.

[BOAC]

After a 'reminder' prod, I was invited to call "Mgr Airport Mapping and AF/D" for an explanation. Since I will not be visiting the US for a while and probably will never operate into Lewiston (if I did I would use the higher of the 3) I have left it dormant. If anyone wishes the contact details, PM me.