qiz about "circling approach"

[eagle737]

hi,guys,here are some qiz about "circling approach", anybody can help me? thanks!
we choose B738 as the model.

Q1. For TERPS, max allowable circling IAS for CAT D is 165kt(738 with gear down/F15 at max landing weight, actual circling IAS will be 161kt), radii for CAT D is 2.3nm, bank angle for CAT D is 20°. Let's say it's a sea-level airport, our TAS at 1000ft will be 173kt, and the radius of the turn will be 1.2nm——less than half of 2.3nm!! that means we can not make a 180° turn within the protective area while we start our continuous turn to the final！Though we can bank steeper and fly slower during our base turn, but that's a sea-level airport! how about a airport with 6000ft elevation?
so Q1 is how can TERPS set 2.3nm for CAT D as the radii while set 165kt as the max allowable IAS??

Q2. i searched the FAA website and found that some changes had been made for the criterias of circling approach, such as radii. According to the FAA doc 8260.3B CHG 21, since last june, FAA finally started to correct the original flow on its circling criterias. Now the radii (Obstacle Evaluation Area (OEA))will be changed with airport elevation/temp change. i don't know if my understanding is correct or not? if i'm right, now the radii is a variant, is that true? anybody can give me a confirmation?
so Q2 is any jeppesen charts changed for this reason? or any plan to change?
any website i can learn from?

Q3.Actually i do not know very well the TERPS, i can't find a way to download a FAR97.20, i only have Instrument procedure manual (IPM) from FAA website. so anybody can tell the difference between TERPS1/2/3?and difference between PANS-OPS3/4/5? or give me a way to download FAR97.20? thanks a lot!

[Whatsit Doingnow]

To answer your question about pans-ops differences, I found this in the Jepps:

PANS OPS —

indicates that the State has specified
that the approach procedure complies with ICAO
Document 8168, Volume II, First or Second Edition.

PANS-OPS3 —

further indicates that holding speeds
to be used are those specified in ICAO Document
8168, Volume II, Third Edition.

NOTE: For applying the correct holding speed, refer
to the respective State RULES AND PROCEDURES
page.

PANS-OPS4 —

further indicates that the acceleration
segment criteria have been deleted, as formerly
published in ICAO Document 8168, Volume II, First,
Second and Third Editions.

NOTE: Acceleration Segment criteria published in
previous editions of Document 8168 are contained
in Appendix 1.

PANS-OPS5 —

further describes APV and VNAV
operations, ACAS procedures and CDFA including

vertical path control methods.

I don't know enough about Terps so I can't help you there, except to say that circling minimum and radius is based on circling speed, not aircraft category. I would assume the 165 kts is because of the tighter turn radius required to remain within the circling area, and if I was circling using Terps procedures I would be using bank angle 30° as well.

No doubt someone with more experience with Terps can enlighten us all a bit more.

[Flaperon777]

The 'assessed circling speed' used by TERPS and FAR is a ground speed after factoring in a 25 kt head wind for the landing runway. So this G/S will change with the quadrant of flight. Just something you would like to think about ..

[Zeffy]

Flaperon777

The 'assessed circling speed' used by TERPS and FAR is a ground speed after factoring in a 25 kt head wind for the landing runway.

Please provide an authoritative cite for that assertion.

[eagle737]

i think before this change(CHG 21) issued last june, TERPS might not assess some important things like temp/elevation/wind while calculating the radii of Obstacle Evaluation Area (OEA).
anybody did a real circling approach in U.S using 737-800? how did u do that?what's the config when u were circling?

[Zeffy]

eagle737

Q3.Actually i do not know very well the TERPS, i can't find a way to download a FAR97.20, i only have Instrument procedure manual (IPM) from FAA website. so anybody can tell the difference between TERPS1/2/3?and difference between PANS-OPS3/4/5? or give me a way to download FAR97.20? thanks a lot!

For eagle (and flaperon)

FAA TERPS Orders are downloadable here.

Cheers

[Whatsit Doingnow]

anybody did a real circling approach in U.S using 737-800? how did u do that?what's the config when u were circling?

I haven't done one in the US, but I have in another country that uses TERPS. Config was F15 gear down on downwind, then abeam threshold start timing and select F25 then F40, turn base after 25 seconds using bank angle 30°. If there are no restrictions about circling directions try and do it so you have a headwind on base and not a tailwind.

[Zeffy]

Whatsit Doingnow

"Config was F15 gear down on downwind, then abeam threshold start timing and select F25 then F40, turn base after 25 seconds using bank angle 30°..."

It's hard to imagine that method working in a TERPS environment in situations where obstacles are lurking immediately beyond the containment areas.

Was the company using Cat C or Cat D minima?

What airspeeds were typical for those configurations?

Recall the B767 CFIT at Busan and note the elapsed time from abeam the threshold to the turn for the right base leg:

...At 11:20:02,the captain said, “Timing” to measure for the commencement of turning base. At this time, according to the aircraft track calculated from the FDR data, the aircraft was positioned about abeam the threshold of runway 18R, with an airspeed of 157 kt, ground speed 177 kt and heading 011 degrees...

At 11:20:32, the captain said,“Flaps 30, already extended,”and then the captain disconnected the autopilot, and manually started to bank right.

Timing may well be appropriate for PANS-OPS maneuvering, but I can't imagine that it works consistently in the TERPS world, especially with significant winds.

[galaxy flyer]

I don't think any FAR 121 in the US has circling in its Ops Specs; just isn't done in the Land of the ILS. Which is why TERPS is so outdated on circling minima; if the airlines aren't interested, the FAA couldn't care less.

'Tis true, circling in a TERPS with nearby terrain is stupid.

GF

[aterpster]

g.f.:

I don't think any FAR 121 in the US has circling in its Ops Specs; just isn't done in the Land of the ILS. Which is why TERPS is so outdated on circling minima; if the airlines aren't interested, the FAA couldn't care less.

I've heard there a a few commuter carriers that do the training, thus have the Ops Specs authorization.

But, there is a trap (as in "terps are traps" ) in the Ops Specs limitation for the majority of carriers that do not train to circle. They are, nonetheless, permitted to circle when the weather is not less than a reported ceiling of 1,000 feet, and visibility of 3 miles. If the circling MDA is 1,000 feet (HAA) or greater, it's real circling, albeit without the training or qualifcations. And, I am aware of at least one carrier that wrote their Ops Specs to permit circling at the actual MDA (when lower than 1,000 HAA) provided the weather is not less than 1,000-3; their POI signed off on it.

Circling does occur at some airports by 121 operators. And, I suspect, when it occasionally does happen, it may very well be an extremely high risk maneuver.

What usually saves the day is that there is not a critical obstacle right at the TERPs limits, at least not in combination with an excursion.

The aviation political interests (especially air carrier) in the U.S. are, in some ways, the most corrupt in the world. They fought TERPs Change 21 for decades. Now that it has published, they have manage thus far to not have it implemented.

I dread the thought of being a passenger arriving at PHLI on a dark, rainy night when circling is done at 1000-3 to Runway 3. At least now it is left circling only. Until a few years ago it was right circling only, with huge rocks just beyond the tiny little TERPs "protection" areas.

[galaxy flyer]

aterpster

Try circling in a heavy C-5 at Kanehoe Bay MCAS on a rainy day with strongish trade wind, inside the island that is a "high profile" noise complainer.

[Border Reiver]

Busan is the only TERPS airfield I've looked at doing the circ approach for, ie done the sim training and flown into the airfield but have only used the straight in approach for real. Zeffy is right about timing, for my operator we do time the downwind but more importantly there is a stored waypoint in the FMS database which we must not fly past.

Training was great fun not sure I want to fly the approach for real.

A320 with flap 3 downwind flap full selected before the base turn.

[ImbracableCrunk]

I've been in the front 3 times for the VIS18R. 2 were go-arounds.

I've been in the back for 3. 2 were go-arounds.

So far, we're averaging .333, which is great in baseball, not so good for approaches.

I miss RNP approaches.

[eagle737]

Thank you for those replies!
I think have full landing config(F40 is the best) before abeam threshold is a good solution for 738's circling. Otherwise we will be too close to(or out of) the boundary, since we don't have Secondary Area while cirling under TERPS, that's extremely dangerous!
And i'm still waiting for answers for my qiz:
any jeppesen charts changed for this reason? or any plan to change? anybody has rumor for me?

thanks!

[Centaurus]

I think have full landing config(F40 is the best) before abeam threshold is a good solution for 738's circling.

And if you then have a engine failure with Flap 40 in level flight at Vref+ 5, you have all the potential for loss of control at low altitude. Just make certain that in the simulator you have practiced engine failures in the Flap 40 configuration as above. Very dangerous indeed.

[Zeffy]

eagle737

Q2. i searched the FAA website and found that some changes had been made for the criterias of circling approach, such as radii. According to the FAA doc 8260.3B CHG 21, since last june, FAA finally started to correct the original flow on its circling criterias. Now the radii (Obstacle Evaluation Area (OEA))will be changed with airport elevation/temp change. i don't know if my understanding is correct or not? if i'm right, now the radii is a variant, is that true? anybody can give me a confirmation?
so Q2 is any jeppesen charts changed for this reason? or any plan to change?
any website i can learn from?

According to the Status Report from the FAA Aeronautical Charting Forum, the revisions to circling minima in TERPS Change 21 have not been implemented. And the methods for depiction of actual Circling Area Radii (CAR) on charts are still under study/coordination.

[Zeffy]

inquiring minds...

So how many operators whose primary areas of operations are PANS-OPS airports have separate, unique SOP's for circling at TERPS locations?

How do the circling methods differ with respect to timing, configuration, speeds, etc.?

Are there other CAA's (in addition to FAA) that permit zero training for circling with a 1000-3 wx stipulation?

[clunckdriver]

Just out of interest you might like to look at my home base {Lachte PQ CSE4} we could have a straight in but CYMX has priority as it was suposed to be a major hub, now doesnt even have a control tower but we are still stuck with the circling apch, also the standard clerance we get at Buttonville {CYKZ} is ADF 21, circling for 33, thank God for GPS overlay when Toronto is covered in its Summer smog! I dont mind circling when there is no alternative but now with Nav Canada it costs an arm and a leg to set up an "aproved" GPS apch, so many operators have an "in house" apch set up at many strips, this is progress?

[aterpster]

Centaurus:

And if you then have a engine failure with Flap 40 in level flight at Vref+ 5, you have all the potential for loss of control at low altitude. Just make certain that in the simulator you have practiced engine failures in the Flap 40 configuration as above. Very dangerous indeed.

Horribly danderous. Approach flaps should be used until turning CTL base or final, in the "slot," and final descent has begun.

[aterpster]

Clunkdriver:

but now with Nav Canada it costs an arm and a leg to set up an "aproved" GPS apch, so many operators have an "in house" apch set up at many strips, this is progress?

It's not an issue of "progress." Establishing IAPs is a very expensive process. In the U.S. it seems free because the taxpayers at large foot the bill. It's only a matter of time before that method of funding comes to an end in the U.S.