Airborne_Again wrote:
It means “Terminal Arrival Altitude” and is part of the published arrival into a PBN procedure.
The reason I commented on the meaning of TAA, for the second A, you had used “Altitude” and in the US, it is an “Area”. I did not know if that was intentional and was a difference in terminology between Europe and US, or just a typo.
Airborne_Again wrote:
He did explain the RNP arrival and initial approach procedures in more detail but that’s very basic and anyone flying IR in Europe would know that already.
It would be nice if it was common knowledge in the US, but it isn’t. Pilots operating under part 91 are not required to receive training for PBN..
“PBN training” is now mandatory here to get the IR revalidation, and is in the form of the FE asking you some questions about what has become called “PBN” (which is a BS term really, since it is nothing to do with “performance” – it is basically GPS-related add-ons to “classical IFR”).
I have never heard that the part – circles are intended to be used operationally (and are far from common; France seems to like them)
while the full – circle is an emergency-only MSA (and is totally universal on Jepp plates)
“PBN” was devised to be a job creation scheme for the IR training industry after GPS caused the bottom to drop out of the navigation business. It was never a problem in the US, for around 20 years, but US had to follow Europe and ICAO once they started pushing it.
In IMC, I will always fly the full procedure, especially in the situation described. The time saving would have been barely a couple of minutes.
Ibra wrote:
So you can operationally descend to TAA altitude after being cleared for approach?Do US plates always have TAA altitude > IAF, IF, FAF altitudes like in KUZA?
Yes, The TAA altitude will always be the same or higher than the IAF segment they serve. When pilots are being radar vectored, they may be vectored as long as they are above the MVA, which may be below the TAA segment altitude. So for example, on the RNAV 2, the MVA in the vicinity of CONEL intersection is 2300 feet. ATC may not clear you for the approach at an altitude below any segment you are to fly, so assigned to maintain 4000 and within 30 NM south of CONEL, the lowest altitude ATC could clear you for the approach would be 3000, The phraseology could be: “Bonanza 12345, cleared direct CONEL, Cleared RNAV 2 approach, Rock Hill.” This clearance would authorize descent to 3000 without needing to state the altitude. If you were being radar vectored at the time, you could receive a clearance that had an altitude restriction, for example: “Bonanza 12345, cleared direct CONEL, maintain 2500 until crossing CONEL, Cleared RNAV 2 approach, Rock Hill.”. 2500 is above the MVA of 2300 and after crossing CONEL, the minimum altitude on the procedure is 2500. ATC can’t issue the clearance: “Bonanza 12345, cleared direct CONEL, maintain 2300 until crossing CONEL, Cleared RNAV 2 approach, Rock Hill.” because 2300 is below the procedure segment between CONEL and AZAKA. You can never be cleared for an approach below the procedure altitude.
Ibra wrote:
In Europe, I see plenty of plates where altitude at IAF, IF, FAF are higher than TAA altitude
So likely raw TAA altitude is unusable? or at least require climb to join RNP procedure?
That chart would not meet TAA standards for FAA TERPS because the segment altitudes are below the charted procedure minimums.
There was a fatal accident at Dillingham, AK (PADL) where a commuter was cleared ambiguously and crashed into a mountain. The aircraft should never have descended below the TAA minimum, once cleared for the approach. see https://reports.aviation-safety.net/2013/20130308-0_B190_N116AX.pdf
Yes, The TAA altitude will always be the same or higher than the IAF segment they serve
That chart would not meet TAA standards for FAA TERPS because the segment altitudes are below the charted procedure minimums.
My guess that would be the main difference between PANS-OPS and TERPS, I have seen load in France and UK where TAA altitude is bellow IAP altitude
Shoreham: TAA at GODOT IAF is less than procedure altitude on RNP02 (no screenshots)
However 2000 is way above the MSA which over the ocean is 1000ft.
I have always completely ignored those part-circles… assuming them to be MSA. In the UK, MSA is defined as (something like) highest object within 5nm plus 1000ft, or some such, but this cannot be observed without getting busted by the CAA for busting Class A 
So, MSA is meaningless anyway. Got to laugh – this is my base
Also that EGKA procedure is never flown other than as published, via the IAFs.
johnh wrote:
If you fly the RNAV to Palo Alto (KPAO) you will NEVER get sent to one of the IAFs (CREDO and SAPID). You will always be vectored to DOCAL, which is an IF. Even if your route happens to take you directly over an IAF, it won’t get mentioned. I must have flown that approach at least 50 times, both in IMC and as a practice in VMC. There is serious terrain around it, too.
Good point. Someone else commented that the approach database does not include all of the points you can begin an approach at, and your example is one of them. The database only includes IAF and feeder route fixes unless the approach only begins at an IF, such as the RNAV 20 at KUZA I posted. To begin the procedure to KPAO at DOCAL, you have to first select the IAF at either SAPID or CREDO and then scroll through the flight plan and select Direct to DOCAL.
Peter wrote:
(which is a BS term really, since it is nothing to do with “performance” – it is basically GPS-related add-ons to “classical IFR”).
It has to do with the performance of the navigation system as regards accuracy and functionality. From a light GA perspective, you are right that it is a GPS thing, but that’s not the case for CAT which makes up the bulk of the IFR traffic. IRU and DME/DME are also covered by the PBN concept.
The whole point of PBN is that it is technology neutral. A RNP 1 STAR can be – and is – flown using any navigational equipment that meets RNP 1 requirements, not just GPS. If a new “Carrington event” would kill all satellites, you could do PBN with eLORAN.
It is just as well that you haven’t heard about Performance-Based Communications and Performance-Based Surveillance. (Ooops. 
)
NCYankee wrote:
The reason I commented on the meaning of TAA, for the second A, you had used “Altitude” and in the US, it is an “Area”. I did not know if that was intentional and was a difference in terminology between Europe and US, or just a typo.
Apparently it is an ICAO-FAA difference.
It is just as well that you haven’t heard about Performance-Based Communications and Performance-Based Surveillance
Too right!
From a light GA perspective, you are right that it is a GPS thing, but that’s not the case for CAT which makes up the bulk of the IFR traffic
Which is totally irrelevant to our flying, and airline ops are very different, being based on INS with DME-DME fixups once over “developed” land areas. And I doubt they will be bypassing any IAFs; most of them even ban circling approaches. They fly NP approaches with the autopilot coupled to a synthetic glideslope.
I once asked a then CAA head of policy on this how come the US managed to use GPS 20 years before Europe and yet the US is not covered in wreckage. He got quite uneasy and walked off.
Apparently it is an ICAO-FAA difference.
Is this documented anywhere?
