Type A and Type B RNAV Arrivals

[some_dude]

Ahh, this discussion reminds me of the ancient Trimble GPS in my old Lear. At one point they (inadvertently, I hope!) removed all waypoints containing the letter "Z" from the database!

Oh well, I figure if it has a "Z" in it, I probably don't want to go there...

 

[SabreFlyR]

Another great discussion (one of few on this board!!). RNAV A and B is not just a problem at the big airports. Take a look at Rifle, CO, a primary divert for Aspen when the weather goes down cause they have an ILS, 7000' runway and it's an easy drive to ASE. EVERY DP is now an RNAV Type B DP!

Look at the back of the Jepps 10-9. You have an Obstacle Departure proceedure for RW 8, but what about RW26? It says to fly the RNAV SID??? WTFO? If you have greater than 10 knots down RW 26 I don't see how you can leagally get out of RIL unless you have a box that can fly these Type A and B DPs? (if it's IFR of course) OBTW field elev is 5500' and ATC (DEN Center) has radar coverage down to about 9000' MSL. So you can't take radar vectors.

I'm frustrated that on any obstacle DP they would tell you to fly an RNAV proceedure. It's like the FAA is not talking to ATC and they aren't talking to us....

Am I wrong? Hopefully this will get us a new box!

ww24dude

Guess I better look at that one now. We're headed to Rifle in couple weeks.
I don't have the Jepp charts handy, but looking at the NOS charts, the obstacle departure is for RW 26. According to how I read AC 90-100 you can still do obstacle departure procedures but not type a or B sid/stars (?).
So at Rifle there is an rnav obstacle departure procedure for RW26 that is a type B.
Are we legal to do this sid or not?

 

[WW24dude]

I hear ya. That's the rub. The ODP (Obstical. Dep. Proc.) says use the RNAV SID (can't remember the name) for a RW 26 Departure. There is no doubt in my mind that if you are not equipped to do RNAV A & B SIDs per AC 90-100, you ARE NOT LEGAL to do that RNAV departure under IFR conditions. The RW 8 ODP uses ground based navaids and has you return to the VOR (at the field) and climb in a holding pattern to 13000' before proceeding on course.

Here is what I see is the coming problem. ALL RNAV SIDs are now either Type A or B (i think, I could be wrong). Prior to AC 90-100 they were listed just as a "RNAV". If you had a GPS or old FMS you could execute these proceedures just fine.
I currently use a UNS-1M ("M" means mistake, but that's besides the point). I have to manually enter waypoints on a SID or STAR (cause the memory is so small). This automatically disquals me from using ANY RNAV A or B type SID/STAR. Besides the fact that I can not determine my RNP capablility in the terminal phase of a flight (except for a GPS approach), cause my box is so old.
I don't think they (FAA) meant for these RNAV proceedures to become such a pain, but by so constraining us as to which equipment we can use to execute them, they have really F'd some of the little guys. An arrival like the one in to DCA is a very complicated arrival, and I can understand the need for an A or B type proceedure with very specific equipment requirements. The problem is that most of these other RNAV proceedures (like Rifle, CO) haven't changed overnight. They are the same ones we where using last year!! What I think is needed is an RNAV Type "C." Basically, if you have a GPS, you can execute this proceedure.

 

[JumpJetter]

Can anybody point out to me an RNAV SID or STAR that is not a Type A or B? Is there such a thing anymore?

thanks
JJ

 

[501261]

501261,Great explanation,Thanks

I agree, excellent post.'Sled

That's the best explaination I've seen yet.

Why thank you, I must have stayed at a Holiday Inn Express last night .

One disclaimer though, this is just my personal opinion, from looking at all the other explanations and from operating a GNS and UNS. I could be way off base and have been before.

 

[GravityHater]

The whole thing is really messed up, and they do not realize it.

Have a look at the Lisse6 into hobby. Not listed as an Rnav arrival at all, BUT you accept it then read the fine print... PART of the route is only for use by RNP2.0 equipped aircraft ONLY. (see the note)

AND many have said the GNS XLS should not do an rnav A or B arrival --- well ours has them! But no where does it give an RNP value and the company's head tech tells me in an email that the GNS XLS is not an RNP-capable navigator... so we can't legally do them.... even if they are right there in the box. &$##&$ Ours navigates them just fine, what the H is up with that?

 

[DC8 Flyer]

The whole thing is really messed up, and they do not realize it.

Have a look at the Lisse6 into hobby. Not listed as an Rnav arrival at all, BUT you accept it then read the fine print... PART of the route is only for use by RNP2.0 equipped aircraft ONLY. (see the note)

AND many have said the GNS XLS should not do an rnav A or B arrival --- well ours has them! But no where does it give an RNP value and the company's head tech tells me in an email that the GNS XLS is not an RNP-capable navigator... so we can't legally do them.... even if they are right there in the box. &$##&$ Ours navigates them just fine, what the H is up with that?

GH

IAH has a few of those arrivals too. It is usually the "heading" part at the end of the arrival that requires you to fly to a fix. Until recently our boxes were only RNP 5.0 and we would have to "decline" the last part of the arrival which usually lead to a heading wrather than tracking the course.

Maybe someone a little more versed in TERPS knowledge can shed some light on why the last part of the arrival would require a RNP 2.0 level of precision?

Look at the Hoagie1 arrival to KIAH. At the end is the 085 course to Ninfa (sp?) you have to have RNP 2.0 to do that little part....

 

[puddlejumper]

The whole thing is really messed up, and they do not realize it.

Have a look at the Lisse6 into hobby. Not listed as an Rnav arrival at all, BUT you accept it then read the fine print... PART of the route is only for use by RNP2.0 equipped aircraft ONLY. (see the note)

AND many have said the GNS XLS should not do an rnav A or B arrival --- well ours has them! But no where does it give an RNP value and the company's head tech tells me in an email that the GNS XLS is not an RNP-capable navigator... so we can't legally do them.... even if they are right there in the box. &$##&$ Ours navigates them just fine, what the H is up with that?

http://www.naco.faa.gov/d-tpp/0511/00198LISSE.PDF

I think you are misinterpreting the note. First, the way I see it, since the leg from SAT to SACGY is 105 nm, you would be too far from SAT to use VOR/DME for reliable navigation. They are saying/requiring that you have an alternate means of navigating that leg. The note states:

Note: Route (SAT-SACGY) for use by E/F/G/R (RNP 2.0) equipped aircraft only.

You must have INS/DME FMS(/E), DME/GPS FMS(/F), GPS(/G) or be /R, which is RNP and able to fly the Required Navigation Performance of 2.0 nm. If you are not opspec or AFM approved RNP, you don't have to worry about the RNP 2.0 thing. If you want to be safe though, you may want to make sure your GPS or FMS scales the CDI sensitivity down from enroute (5.0 nm fullscale) to terminal (1.0 nm). I'm not sure if there are FMSes or GPSes that have a 2.0 nm sensitivity setting, but you may be able to do that manually. I would be willing to bet that if your FMS has this procedure in the database, it will go automatically to terminal sensitivity, just like it will go to approach sensitivity (0.3 nm) at 2 nm outside the FAF on an RNAV approach.

Here's a link to a little discussion on RNP. http://www.jeppesen.com/download/briefbull/den01-j.pdf Maybe someone who actually files /R or /Q correctly who is approved for RNP can chime in and let us know if we're thinking along the right track here. (Pun wasn't intended at first)

I hope that makes sense, and clears up any misunderstanding you may have.

 

[JimNtexas]

I fly with a King 89b, thanks for pointing this out!

 

[puddlejumper]

I needed to BUMP this thread for someone who thought it was deleted! I don't have much to add, other than, what's up with all the corporate guys who file /Q? Is being RNP-equipped more common than I thought? /R is no longer GPS nor RNAV, it's RNP. /Q is /R with RVSM. Am I missing something here?

-PJ