Actually... I discovered that all I need is the Vertical Error Budget (VEB) for obstacles that fall within the Obstacle Evaluation Area (OEA) of the Final Approach Segment (FAS).

 

The primary limiting (controlling) obstacle for my track to RW08 using RNP 0.10 is a tower (588ft AMSL) on Pederson Hill. The minimum VEB I calculated was 290ft. Thus, 588ft+290ft becomes the minimum height I need to "get over that controlling obstacle", even though it's 0.14nm left of my track. That makes my fictional procedure not feasible, as we always knew it to be. I'll keep it in my FMC though, and fly it in VMC. I'll fly through the cut in more limiting conditions.

 

Interestingly Joseph, I got 15.97 for my Obstacle Clearance Slope.

 

It's been a great learning curve.

 

References:

FAA Order 8260.58 - United States Standard for Performance Based Navigation (PBN) Instrument Procedure Design, Volume 5.

 

RNP AR Calculator that I used below is superseded by the calculators in FAA Order 8260.58

https://www.faa.gov/about/office_org/headquarters_offices/avs/offices/afs/afs400/afs420/terps_tools/media/rnp_ar.zip

I did a rough calculation simply using the ridge as the controlling obstacle. There was a PDF that was released a while ago that listed the controlling obstacles for both runways for various RNP values:

 

Thanks for the link to the PBN design doc, I've never seen that before. As to the slope of the OCS, the 15.97:1 slope translates to a 6.38° GPA, so my rough guess on the surface wasn't that far off. :wink:

Oooh, is that report publicly available, would be well worth a read.

 

My bad about the OCS, mate. Clearly you're sharper on the subject than I. I'm just playing around with this stuff

 

Thanks for your continued input.

It's part of a report issued by the Juneau Airport, and is publicly available on the Juneau City Website. (Should keep stearmandriver and spin737 in the clear).

 

http://www.juneau.org/airport/documents/AppendixJRNVImpacts.pdf

Hey all; really hate to resurrect this thread, but possibly useful info for those interested - someone pointed out to me that there's a collection of Alaska's RNP procedures posted in the forums of an Alaska virtual airline. http://www.flyalaskava.org/ Looks like you don't have to join the airline so to speak, just register for the forums, and they're under "resources" or something similar. They look like slightly older but perfectly serviceable versions and they've got a pretty complete collection, if anyone's still interested.

Hello Andrew, I am interested thanks for the tip.

 

Speaking of RNAV for ASA, I have been having lots of fun with the RNAV RWY 14 approach into KSTS. Need Orbx NCA and the airport but it is so nice. I know your bird does not fly in there only the DH, but in the sim anything goes. Short runway, Orbx stuff 35% off right now till end December. Not advertising just a heads up.

Hey all; really hate to resurrect this thread, but possibly useful info for those interested - someone pointed out to me that there's a collection of Alaska's RNP procedures posted in the forums of an Alaska virtual airline. http://www.flyalaskava.org/ Looks like you don't have to join the airline so to speak, just register for the forums, and they're under "resources" or something similar. They look like slightly older but perfectly serviceable versions and they've got a pretty complete collection, if anyone's still interested.

Why would you hate to resurrect the thread?

 

Finding, designing and writing new RNAV RNP Procedures for the NGX or any aircraft that can use NGX FMC route data AND has the RNP capability, has been most rewarding, and probably one of the most interesting and challenging topics on the entire board!

 

Thanks all for contributing, especially Stearmandriver for creating the thread!

 

Chas

You guys might be pleased to find some updated RNP procedures for use with the PMDG 737 NGX. I'm truly amazed at how well these things work! Search the Avsim file library for: asarnp.zip

 

Juneau

Ketchikan

Petersburg

Wrangle

Sitka