GPS Alternate

[brett529]

It is my understanding that if you file GPS to your destination on an IFR flight plan and an alternate is required, then the alternate must have other than a GPS approach published and you and the aircraft must be able to perform it. I have read over the FARs and I cannot find any information on this. Is this regulatory in nature?

[dc3flyer]

I am pretty sure it is regulatory, but I don't have my FAR/AIM with me.

[tgrayson]

Originally Posted by brett529

Is this regulatory in nature?

Sorta. All GPS approaches were labeled as "NA" as alternates. This has changed with the advent of WAAS, and many of the NA's are being removed.

There was also some language in the AIM if you were planning on using GPS to identify fixes on standard approaches, then any alternate you file must have approaches you can fly that don't rely on GPS.

However, the AIM section has been completely rewritten in the last version and I've only skimmed it. That's where you ought to go.

[brett529]

Originally Posted by tgrayson

Sorta. All GPS approaches were labeled as "NA" as alternates. This has changed with the advent of WAAS, and many of the NA's are being removed.

There was also some language in the AIM if you were planning on using GPS to identify fixes on standard approaches, then any alternate you file must have approaches you can fly that don't rely on GPS.

However, the AIM section has been completely rewritten in the last version and I've only skimmed it. That's where you ought to go.

Found this in the AIM:

g. GPS Approach Procedures
As the production of stand-alone GPS approaches has progressed, many of the original overlay approaches have been replaced with stand-alone procedures specifically designed for use by GPS systems. The title of the remaining GPS overlay procedures has been revised on the approach chart to "or GPS" (e.g., VOR or GPS RWY 24). Therefore, all the approaches that can be used by GPS now contain "GPS" in the title (e.g., "VOR or GPS RWY 24," "GPS RWY 24," or "RNAV (GPS) RWY 24"). During these GPS approaches, underlying ground-based NAVAIDs are not required to be operational and associated aircraft avionics need not be installed, operational, turned on or monitored (monitoring of the underlying approach is suggested when equipment is available and functional). Existing overlay approaches may be requested using the GPS title, such as "GPS RWY 24" for the VOR or GPS RWY 24.
NOTE-
Any required alternate airport must have an approved instrument approach procedure other than GPS that is anticipated to be operational and available at the estimated time of arrival, and which the aircraft is equipped to fly.

(a) Due to initial system limitation, there are certain restrictions on WAAS operations. Pilots may plan to use any instrument approach authorized for use with WAAS avionics at a required alternate. However, when using WAAS at an alternate airport, flight planning must be based on flying the RNAV (GPS) LNAV minima line, or minima on a GPS approach procedure, or conventional approach procedure with "or GPS" in the title. Code of Federal Regulation (CFR) Part 91 nonprecision weather requirements must be used for planning. Upon arrival at an alternate, when the WAAS navigation system indicates that LNAV/VNAV or LPV service is available, then vertical guidance may be used to complete the approach using the displayed level of service. The FAA has begun removing the </IMG> NA (Alternate Minimums Not Authorized) symbol from select RNAV (GPS) and GPS approach procedures so they may be used by approach approved WAAS receivers at alternate airports. Some approach procedures will still require the </IMG> NA for other reasons, such as no weather reporting, so it cannot be removed from all procedures. Since every procedure must be individually evaluated, removal of the </IMG> NA from RNAV (GPS) and GPS procedures will take some time.

Still couldnt find anything in the FARs though.

[tgrayson]

Originally Posted by brett529

Still couldnt find anything in the FARs though.

No, there's nothing in the FARs. Although the AIM isn't regulatory, I wouldn't take that fact too seriously. If you deviate from its advice and run into problems, the AIM will be referenced during your hearings. I doubt, though, anyone is looking too closely at pilot behavior in this regard.