What does 'A' indicate?

[nsproles]

The approach plate for KANK in Colorado is referred to as RNAV(GPS)-A.  I am aware of what RNAV(GPS) means, but what does the 'A' indicate?  Normally the runway direction is shown here.

[Nels_Anderson]

I believe the lack of a runway, replaced by an "A", means that the approach brings you to the airport, but not aligned with any runway. I suspect if you look further down the chart you'll see that the approach ends at a relatively high altitude at which you circle to land at the desired runway.

[PhrogPhlyer]

Yes, the "-A" indicated a Circling Approach.

The FAA's Chart Users Guide contains all these little details.

https://aeronav.faa.gov/user_guide/20230810/cug-complete.pdf

 

 

[nsproles]

Thank you both for that and for the reference to the FAA Guide. 

Perhaps you can help me further.  I put my flight plan in to fly this approach in the TBM 930.  The autopilot does the flight reversal at 13400 ft at NAMDE and VNAV then takes me down to 12000 ft to the FAF at SOSE.  No problems so far.  However, once at the FAF, VNAV stops - GPS will take me over the MAP but at 12000 ft even though I have set VNAV to take me down to the circling minimum of 9720 ft.  APR mode will not turn on, by the way.  I am confused as to why this occurs.  I understand that once at the FAF I should be looking for the airfield and be configured for a landing if and when I see it.  However, I expected that the auto pilot would take me to the MAP, at the circling altitude, for me to execute the missed approach procedure if I had not been able to see the airfield beforehand.  If it is intended that a manual sequence be used after the FAF, why would it not be shown as such on the approach plate?  Instead, on the plate, the leg from the FAF to the MAP is shown as a solid line.

[PhrogPhlyer]

10 hours ago, nsproles said:

APR mode will not turn on, by the way.

A circling approach is a non-precision approach, there is no vertical guidance to get you down to you MDA (minimum decent altitude). 

As the pilot, you could decent from the blocked altitudes at NAMDE(16000-13400) either rapidly to the MDA(9720 and not below the hard altitude of 12000 at SOSEE) and then level off until at the MAP (YOBUT), or determine a decent rate based upon your ground speed to create a more even decent profile.

With no vertical guidance (glide slope) there are no approach tolerances to be followed for APR on the autopilot. APR gives you both course and vertical guidance.

[nsproles]

 

On 9/26/2023 at 10:13 PM, PhrogPhlyer said:

With no vertical guidance (glide slope) there are no approach tolerances to be followed for APR on the autopilot. APR gives you both course and vertical guidance.

Are you saying that, having reached SOSE at 12000 ft, I would need to disengage the autopilot and fly down to the MAP manually unless I can see my way clear to execute a normal landing before reaching the MAP?  Unless i disengage the autopilot, I continue to maintain 12000ft.

[PhrogPhlyer]

6 hours ago, nsproles said:

I would need to disengage the autopilot

You could keep the autopilot engaged, resetting the alt to 9720, letting the autopilot continue with course guidance and altitude to the MDA.

When at YOBUT you either, 1) see the airport environment clear enough to continue decent to pattern altitude while circling to the active runway, or 2) execute the missed approach (by hand or autopilot), by climbing to 16200 while flying direct to OKAE then 015 to RONBE.