New, New TAA RNAV IAP Design

aterpster

aterpster

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aterpster
For years we had TAA IAPs with “T” corner posts. Under 8260.58 TF-to-TF turn angle limitations vs. distance that design went out the window. So the last couple of years we have had new TAA IAPs with no corner posts. Now, the corner posts have returned, but with a 60 degree intercept angle vs. 90 degrees.

See attached.
 

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  • KRZR New TAA Concept.pdf
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If I am reading that correctly, if I am under 5100 feet when I hit MMARS I can skip the HPILPT? (coming in from the SW-ish that is)
 
aterpster said:
For years we had TAA IAPs with “T” corner posts. Under 8260.58 TF-to-TF turn angle limitations vs. distance that design went out the window. So the last couple of years we have had new TAA IAPs with no corner posts. Now, the corner posts have returned, but with a 60 degree intercept angle vs. 90 degrees.

See attached.
Click to expand...

I made this comment on another thread, but how often does anyone actually get cleared to fly a TAA approach using the publishing altitudes? I have yet to be cleared to fly any TAA approach that way, I always get sent to the IAF even out in the sticks at the sleepiest airports around. All these shapes are fine, but is anyone using them?
 
Alexb2000 said:
I made this comment on another thread, but how often does anyone actually get cleared to fly a TAA approach using the publishing altitudes? I have yet to be cleared to fly any TAA approach that way, I always get sent to the IAF even out in the sticks at the sleepiest airports around. All these shapes are fine, but is anyone using them?
Click to expand...

I just did on the last one I flew into TKX.
 
aterpster said:
For years we had TAA IAPs with “T” corner posts. Under 8260.58 TF-to-TF turn angle limitations vs. distance that design went out the window. So the last couple of years we have had new TAA IAPs with no corner posts. Now, the corner posts have returned, but with a 60 degree intercept angle vs. 90 degrees.

See attached.
Click to expand...
Are we also going to see an accompanying change to 7110.65 changing the limit for clearing folks direct-IF/straight-in on GPS approaches from 90 degrees to 60 degrees? And do you know what precipitated these changes (limiting the turn at the IF to 60 degrees and lengthening the run-ins from the other IAFs to 8nm vice the old 5nm)?
 
Last edited:
EdFred said:
If I am reading that correctly, if I am under 5100 feet when I hit MMARS I can skip the HPILPT? (coming in from the SW-ish that is)
Click to expand...
That's close. What it means is if you're arriving in the southwest pie slice labeled MMARS cleared direct MMARS and cleared for the approach, you descend to 5100 when you're inside 30nm from MMARS, then descend to 4100 when within 5nm of MMARS, and when you cross MMARS you proceed straight-in descending to 2700. If you arrive in one of the other two pie slices, you should be cleared to YODUL or ZUBEB as appropriate, and then make the 8-mile run to MMARS at 3900/4100 as appropriate and go straight-in from MMARS. Only way you do the HPILPT would be if cleared direct to MMARS rather than YODUL or ZUBEB when starting outside the abovementioned MMARS pie slice.
 
Ron Levy said:
That's close. What it means is if you're arriving in the southwest pie slice labeled MMARS cleared direct MMARS and cleared for the approach, you descend to 5100 when you're inside 30nm from MMARS, then descend to 4100 when within 5nm of MMARS, and when you cross MMARS you proceed straight-in descending to 2700. If you arrive in one of the other two pie slices, you should be cleared to YODUL or ZUBEB as appropriate, and then make the 8-mile run to MMARS at 3900/4100 as appropriate and go straight-in from MMARS. Only way you do the HPILPT would be if cleared direct to MMARS rather than YODUL or ZUBEB when starting outside the abovementioned MMARS pie slice.
Click to expand...

Oh goody. That's what I thought all that stuff meant.
 
Ron Levy said:
That's close. What it means is if you're arriving in the southwest pie slice labeled MMARS cleared direct MMARS and cleared for the approach, you descend to 5100 when you're inside 30nm from MMARS, then descend to 4100 when within 5nm of MMARS, and when you cross MMARS you proceed straight-in descending to 2700. If you arrive in one of the other two pie slices, you should be cleared to YODUL or ZUBEB as appropriate, and then make the 8-mile run to MMARS at 3900/4100 as appropriate and go straight-in from MMARS. Only way you do the HPILPT would be if cleared direct to MMARS rather than YODUL or ZUBEB when starting outside the abovementioned MMARS pie slice.
Click to expand...

That's way better than what we have now. The whole flying a hold without a need to lose altitude always bothered me.
 
John Collins told me on the Red Board that my question assumes facts not in evidence. The approach Wally posted is just an example of one produced under an expanded set of options, not a new standard to replace the classic T-shaped TAA. And it doesn't change what it says in 4-8-1 about direct-IF/straight-in.
 
Ron Levy said:
Holding pattern in lieu of procedure turn. Part of instrument approaches -- uses a holding pattern instead of a classic procedure turn for course reversal. See AIM 5-4-10 for details.
Click to expand...

AIM 5-4-9
 
Ron Levy said:
John Collins told me on the Red Board that my question assumes facts not in evidence. The approach Wally posted is just an example of one produced under an expanded set of options, not a new standard to replace the classic T-shaped TAA. And it doesn't change what it says in 4-8-1 about direct-IF/straight-in.
Click to expand...

We have done a bit of assessing of the proposed RZR IAPs. If you enter either the right or left base TAA near the dividing line you are going to be facing a course change in excess of 130 degrees. The FAA doesn't allow that for any IAP entry from an airway.

I don't believe they have thought this design through.
 
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