PAJN Runway 26 RNP Approach

[NGXfanatic 85]

I read Chesley "Sully" Sullenberger's book "Highest Honor" , and he tells a story of an approach he conducted into a west coast airport in an A321, where he coasted on idle from cruise to the runway. He says the touchdown was so smooth, the ground spoilers didn't activate!I believe it was a red eye flight without much arrival traffic, so ATC gave him permission for a direct to runway constant descent approach.

[mcbellette 145]

So far RNP approaches in the US are only about beating the weather and getting to the airport in weather conditions that otherwise would be impossible. One exception may be the KDCA RNP where it is primarily about the noise footprint. The steep approaches that save fuel are in experimental phase and are separate from RNP, they are called tailored arrivals. Such approaches do not have a fixed 'map' but rather the approach sequence is up-linked by ATC to the specially equipped aircraft. The airport where most such trails are conducted in US (over 3500 flown) is San Francisco but they are usually flown at night when traffic is light. I think we are still a long way from times when majority of airports in the US will have it available and they will be flown even during peak times.

Michal, just wanted to say I did know that the steep approaches have nothing to do with RNP. I brought it up as we were talking about approach procedures in general.

[sekos 0]

Speaking of time/cost saving approaches, I read in the Australian Aviation magazine a number of issues ago that there are talks among some airlines - Qantas included, I believe - and Airservices Australia (the body which provides ATC and radar services to Australian airports/airspace) as to the pro's and con's to increasing the approach angle from the usual 3.5 degrees to make it steeper. The rationale behind this was that a steeper approach would require less engine thrust and a more steady descent from cruise, hence making the approach and landing quieter while also burning less fuel. Have you heard of anything like this in the States, Robert? It seems like a good idea worth investigating.

Hi im atco at lkaa and i must say we dont have any RNP here and i dont know about any other airfield in europe that does. I think its a because our europian style of controling is more strick than us so its always a same star for everyone. But we r now testing CDA stars for number of airfield on low traffic hours which is the Continues discend approach when u give an a/c clearence from almost his crusing level to 4000ft (for prague) and to ils that is a big fuel saver because it on idle all the way in and on one medium size a/c it can be up 300kg save on each flight.Jiri Sekerka

[CapnOz 110]

- the use of things like RNP are so simple and logical. It makes me wonder why it has taken so long to figure it out. With that said, its pretty cool that PMDG has decided to implement this stuff.

[michal 44]

- the use of things like RNP are so simple and logical. It makes me wonder why it has taken so long to figure it out.

It is not exactly 'simple' since special crew/aircraft certification is required.It costs $$.Nobody does it because it is "cool" but because it may solve some problems.Some airlines don't need them.

[559AS 11]

Made some calls about "hypothetically" allowing use of the PAJN RNP 26 and RNP 8 for commercial flight sim use, and got a (very friendly) "its not going to happen" response. I was told that its not a case of protecting proprietor information, but just more of a legal liability. That being said, I was given a smile and a nod when I asked if I could use the charts for flight sim use. They were very interested in the NGX, and impressed when I showed the video of the KCLM crosswind approach. And Ryan, my job is still fully intact.

[michal 44]

It is all about traffic density, and higher precision means you can pack them in tighter.

I disagree about that. As was stated above it is all about getting to airports in difficult terrain that otherwise would be impossible in some bad IMC conditions. There are numerous sources that survey RNP benefits and none mentions anything about packing traffic tighter. The other benefits that are often quoted are reduced noise and fuel saved due to more direct path. Majority of RNP approaches go to airports with rather sparse traffic, something like Deadhorse airport in Alaska.

[mcbellette 145]

Queenstown in NZ is an airport where Qantas pioneered the RNP procedures. It's hardly a very busy airport, but is surrounded by mountainous terrain. I believe their reason for using RNP is that it makes for safer approaches (especially in less than perfect weather) with lower minimums (hence, fewer go-arounds and less fuel wasted). It's got nothing to do with traffic density as far as I know.

[neilbradley1 2]

This link will show you the published NZQN RNP approach plates for RWY 05/23. You will note that they are for APPROVED OPERATORS only. This means that the NZ aviation authorities have to be satisfied that an airline company has provided the appropriate training and documentation to its aircrew before they can fly the approaches.http://www.aip.net.nz/pdf/NZQN_45.1_45.2.pdfNeil Bradley

[ZanderMiller 0]

Found and OLD version of the PAJN 26RNP in a FAA document while I was actually searching for something unrelated. See Page 16 of this document.http://www.faa.gov/about/office_org/headquarters_offices/ato/service_units/techops/navservices/gnss/library/documents/media/LAAS_IBM/FSF_LAAS_Safety_Report-2004.docSomeone correct me, but based on the date, I believe this might be close to when ASA first developed the PAJN RNP approach?Happy SimmingMK

[Chaos81 110]

Nice find, even if it is a bit old.

[Tabs 2,790]

That PAJN one should actually be codable for the NGX using that chart. Stuff like the Queenstown one is where the problem is. Having the chart doesn't tell you anything about what those curves actually are in a mathematical sense to be able to code them. They're radius-to-fix legs, but the chart doesn't give you any information on exactly what the radius of the arc is, where the center point for the circle the arc is a segment of is located, or even what the lat/lon of the fixes are etc.Just gonna have to wait on the curved ones I'm afraid, you need real navdata that has the curves defined.

[Guest dlrk]

With regard to RSR's comment on late summer, does that mean the NGX will be delayed until late summer? Or will it be released with features disabled for legal BS?

[mcbellette 145]

I hope not summer - that means December here!!! lol

[Chaos81 110]

I took it to mean there are things the NGX is programmed to do, that we won't be able to do until we have the proper navdata. We won't have the proper navdata until the contracts are signed, and that might not be until late summer. Nothing to do with the NGX being delayed.