Terpster,

I see in the FAA guidance, AC 90-101A the CG that you refer to.

The 'sample' plate they give, shows quite a few waivers, first off, the different RNP levels, RNP 0.15 at the IAF?!?!?, the angle before final segment (they dont want to admit the FMS would do some sortof turn here), missed approach less than RNP 1, DA of 276, but you must make 4000' by WODVU ??...I know this is an example...but I believe this is the plate for KPDX

Some of the public RNP plates are even better...look at the helo RNP for NY,NY..the entire procedure is over the Hudson, including the MAP, but you go 12.9 miles visual to the helipad...

FlightPathOBN:

None of the options shown all those example charts require waivers. They are all provided for in criteria.

What is supposed to require a waiver, but this comes and goes, is when a single-string line of minimums cannot be provided as one of the lines of minimums. This often requires two procedures to a given runway.

Climb gradients are very common in RNP AR IAPs in the western U.S. Some are at the maximum of 425 feet per mile, others are close to that.
I can't speak to a 'Copter RNP AR. Those have been designed by one third-party developer who has the expertise.

Pugilistic Animus:

This is only required of the commercial operators of Part 25 aircraft. If it wasn't required of them, then they wouldn't be providing the highest level of safety expected of them.

Sorry cant agree with that, .52 is very 0.30 specific on approach and RNP 1. there is an option to go to a smaller RNP, but that requires approval from 420...if you are a 3rd party developer.

"The standard MA construction is a continuation of the final approach course. The OEA expands at a 15° splay from the FAS RNP value to a value of 1.0, using a 40:1 OCS slope ratio"

"Dsplay = 7.464(1−RNPFAS )" the standard calculations have some of these values built in such as the RNP approach to RNP 1 missed splay distance.

The 8260.52_V7.4 spreadsheets that the FAA requires us to use has this hard coded as well...for the MA splay, Formula 4-1, the only input is the RNP value for the approach...and the VEB OCS Form 3-17 is hard locked at RNP .3...

FlightPathOBN:

Could be, I don't know. My comments are about RNP AR IAPs developed by the FAA.

Third-party developers design specials I never see. The very few public RNP AR the third-party developers have developed are all quite simple at easy (not obstacle or terrain rich) airports. BDL and SAV come to mind.

Two questions, Aterpster on KBDL and KSAV

KBDL RNAV (RNP) 15, why is there a wingspan limitation. I'm based there and it escapes me.

KSAV RNAV (RNP) 27, why is there a "RF required" notations, as all the transitions to final seem to be RF legs?

GF

exactly..I am very familiar with BDL....thats about all the FAA will let a 3rd party do...AND they gave themselves a waiver for the trees on the ridge on approach, but not for 3rd party...

The wingspan limit is to keep the design within the parameters of a 737 NG.

KSAV--

http://www.faa.gov/about/office_org/...overLetter.pdf

BTW...a 4.3r to a 5.2r is a busted curve....this must not fly very well...

You would have to ask Jepp what the hell they meant, it looks like radio fix, not RF turns...

g.f.:

I believe you mean Runway 28. Also, I believe you meant to ask why is there not an RF required notation. The entry from FEXEM does not require RF so instead of the procedure stating "GPS and RF Required" each IAF except for FEXEM should be annotated "RF Required." But, it is a third-party procedure and the FAA folks who develop FAA RNP AR procedures refuse to do any QC on third-party procedures. I forced Ball Note 5 "radar required" for FEXEM and UCETA, because I commented for my organization during coordination. But, I missed the RF notation screw-up. In any case, I'm not Jeppesen's or GE's QC guy. :) I believe this is a Jeppesen developed procedure (wearing their third-party developer hat, not their chart maker hat).

FlightPathOBN:

Those are distances along the RF legs, not radii. Radii are not shown on the chart. They are on source and usually shown in the FMS legs page.

Source shows the radius for each of those legs to be 3.70 miles:

http://avn.faa.gov/acifp/ndbr/00380R..._ORIG_NDBR.pdf

http://i202.photobucket.com/albums/a...t/BDLRNP15.png

Unlike an ILS, an airplane flying an RNP approach may encounter an RF leg in the final.

The RF leg may require significant bank angle. (Not the case for this approach, but the issue remains applicable.)

The "down wing" on large airplanes can extend below the normal gear height. So appropriate allowances must be made.

Per Appendix 1 in the 8260.52, the assumptions are:

Because the BDL procedure is restricted to Cat C aircraft, the designer also had to note that the approach was designed using narrow-body geometries. (2 X 68' = 136'). :8

Hope you can win at least a few beer-bets with that bit of arcana, gf

"Amaze your friends !"
:ok:

Thanks, Zeffy, Aterpster, FlightOBN

Aterpster, please check your PM.

GF

terpster, you crack me up...

History of KBDL:

The FAA used the airport as a certification of the 3rd party developer Naverus. The FAA and Naverus designed procedures simultaneously for the FAA to determine if Naverus would have the same solution. The design parameters were set with a 737NG as the basis for the design, hence the wingspan limit on ClassC...

The FAA design came in with a lower DA because they waivered the canopy height on the hillside to the approach.

BTW..BDL was the foundation for the need to require the precipitous terrain algorithm...

Now that may get you a few beers...

Zeffy:

The wingspan aspect of 8260.52 has been questioned by not a few folks, at least for larger RNP values.

I guess if the procedure is only RNP 0.10 and the FROP is at minimum distance then the large bird's wing could drop below the VEB and in extreme circumstances dig into the dirt in a maxed out obstacle environment. We wouldn't want a 747 doing that and not even (I guess) a 380.:ok:

The wingspan has been used, creatively, to create procedures for the 737 capabilities, without the limitations of other aircraft designated as Class C. The 136 leaves out the 757 as an example.

That class designation, with final approach speed of 140kts, no longer has any basis in reality.

Also, with some of the Class C aircraft such as the 757, having bank angle limits of 25 degrees, thus the 18 degree FAA limit, this severely restricts the 737 which can bank limit to 30.

Why did I crack you up? Those aren't my comments. :=

Sorry to terpster and Zeffy...

the 'quotes' portion of this thread diso'd on me...

the text and quotes are not related..

you still crack me up....

As I stated previously, FAA Aero Nav Services, the FAA entity that develops most FAA RNP AR IAPs, will have nothing to do with third-party developed RNP AR IAPs. No review and no QC. Here is the disclaimer on Aero Nav Services National Database Review for the SAV Runway 28 RNP AR IAP. Database review isan important component of the requirement for operators or their authorized designee to validate RNP AR database source.

http://i201.photobucket.com/albums/a...VNDBReview.jpg

I misspoke previously when I stated that the Jepp chart for SAV RNP Y 28 didn't have the RF leg annotation at the required points. I missed the ball note.

Below I include that chart and the FAA version for comparison. The FAA chart is arguably easier to decipher in this regard.


http://i201.photobucket.com/albums/a...pSAVRNPY28.jpg



http://i201.photobucket.com/albums/a.../SAV28RNPY.jpg

3rd party design get full review from many different parts of the FAA. I designed and submitted PSP, SCC, and parts of BDL from beginning to end with the FAA.
The 8260 forms are required and reviewed, waivers are reviewed, the procedures are required to be sim checked, obstacle validated, and flight validated.

It AFS 420/460 and AVN that deal with procedure design.

"The Flight Procedures Standards Branch is the principal element of the Flight Technologies and Procedures Division for 14 CFR Part 97, non Part 97 terminal instrument procedures, 14 CFR, Part 95 en route instrument procedures, the administration of the flight procedures and airspace program, and the direction, control, management, and program analysis of all instrument flight procedure standards and criteria development programs."

Flight Procedure Implementation and Oversight Branch-Policies & Guidance

FlightPathOBN:

I understand that. Nonetheless, my statement is correct. The real QC expertise lies within Aero Nav Services, because they design and QC FAA-developed RNP AR IAPs all the time.

As to ASF, I have no involvement with the third-party process, but I understand AFS-460 has that program.

AFS-420 may provide some ad hoc input, but as your mission statement sets forth, they develop the TERPs standards and maintain the 8260.19 handbook.

I deal with both Aero Nav Services and AFS-420 all the time.:)

The Aero Nav folks have my picture on the wall for dart practice.;)