GPS Alternate Minimums - Help Me Understand

Skid

Skid

Pre-takeoff checklist
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Skid
I’ll try to keep this short. I think I have a good grasp of when I can and can’t use an airport as an alternate (when considering GPS) but I’m unclear as to what the weather has to be:

(c) For flight planning purposes, TSOC129() and TSOC196()-equipped users (GPS users) whose navigation systems have fault detection and exclusion (FDE) capability, who perform a preflight RAIM prediction for the approach integrity at the airport where the RNAV (GPS) approach will be flown, and have proper knowledge and any required training and/or approval to conduct a GPS-based IAP, may file based on a GPS-based IAP at either the destination or the alternate airport, but not at both locations. At the alternate airport, pilots may plan for:

(1) Lateral navigation (LNAV) or circling minimum descent altitude (MDA);

(2) LNAV/vertical navigation (LNAV/VNAV) DA, if equipped with and using approved barometric vertical navigation (baroVNAV) equipment;

(3) RNP 0.3 DA on an RNAV (RNP) IAP, if they are specifically authorized users using approved baroVNAV equipment and the pilot has verified required navigation performance (RNP) availability through an approved prediction program.
​
Is this basically saying I should be using the non precision alternate mins of 800-2, or looking up the stated minimums in the plate and ensuring the weather is above this?

I’ve been staring at this stuff all day so bear with me if this is a dumb question.
 
DGlaeser said:
Your non-precision alternate needs to have at least 800-2 forecast.
Click to expand...

Correct, all you need to remember, does the alternate have a precision or non-precision approach. That determines whether you need 600 and 2 or 800 and 2.
It's that simple.
 
Aren't LPV, LNAV/VNAV, and Baro VNAV considered to be an approach with vertical guidance (APV) and therefore technically non-precision? And therefore 800-2 would be used all the time? If so, I'm confused why the AIM just doesn't state the simplified non-precision approach minimums.
 
Skid said:
Aren't LPV, LNAV/VNAV, and Baro VNAV considered to be an approach with vertical guidance (APV) and therefore technically non-precision? And therefore 800-2 would be used all the time? If so, I'm confused why the AIM just doesn't state the simplified non-precision approach minimums.
Click to expand...
No. Technically, for the purpose of alternate minimums, they are treated by the FAA as nonprecision approaches.
 
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