Splitting hairs? GPS not approved for "primary" navigation

Sam D

Sam D

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Sam D
I was just reading an article reprinted from the FAA Aviation News publication (which I didn't know existed). The article, from the March/April 2007 edition and titled "The Future is Now and You'd Better Catch Up", states:

"We often forget that GPS is not approved as a primary method of navigation."

It goes on to reference an article in the Nov/Dec edition which does not say anything about GPS not being "primary". It, and the AIM (1-1-19(d)(1)(b), talk about having an alternate means of navigation in case RAIM is lost but nothing about "primary" that I could find.

So here's the question: Is this a significant difference? If so, which is correct?

Thanks,
Sam​
 
Non-WAAS (TSO C129A?) GPS is not approved as a primary source of navigation under IFR. That means you MUST have another source of navigation equipment (VOR is one) and it MUST work. You may navigate via GPS, but you gotta have the other options.

Newer (TSO C146?) WAAS GPS is indeed approved for primary navigation under IFR.

Hope this helps.
 
TMetzinger said:
Non-WAAS (TSO C129A?) GPS is not approved as a primary source of navigation under IFR. That means you MUST have another source of navigation equipment (VOR is one) and it MUST work. You may navigate via GPS, but you gotta have the other options.

Newer (TSO C146?) WAAS GPS is indeed approved for primary navigation under IFR.

Hope this helps.
Click to expand...

It does help, and there it is in AIM 1-1-20(c)(7). I suppose the article could have pointed this (growing) exception out.
 
Last edited:
"Primary" may just be bad wordsmithing by the author of the article. Would "sole available" have worked better?
 
midlifeflyer said:
"Primary" may just be bad wordsmithing by the author of the article. Would "sole available" have worked better?
Click to expand...

Yes. And in light of the exchange above, I would also modify "GPS" to be "non-WAAS GPS".
 
The instructions for how to suggest changes to the AIM are at the front of the AIM. And they really do listen -- they re-reworded the section on when HPILPT is/is not required based on a submission I sent in after they reworded it into incomprehensibility a couple of years ago.
 
Ron Levy said:
The instructions for how to suggest changes to the AIM are at the front of the AIM. And they really do listen -- they re-reworded the section on when HPILPT is/is not required based on a submission I sent in after they reworded it into incomprehensibility a couple of years ago.
Click to expand...

Done! I'm curious to see what happens...
 
sba55 said:
Hey Sam, didn't you say you would buy me lunch in return for answering your IFR questions? :D;):yes:
Click to expand...

First, I would actually need to be in SF. In the last couple months, I've been in: NY, Phoenix, Amsterdam, NY (currently) and headed to Boulder this weekend!

But yes, that is the deal. Of course, you need to get all the answers correct or else you buy. I think I'll bring some back issues of IFR Magazine...:D

Sam
 
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