Practice approach at Class C

[Palmpilot]

...Although I doubt there is a WAAS unit that is not approved....

Just to clarify, there are many hand-held WAAS units, but according to AIM Table 1-1-6 there are no hand-held units that are approved for IFR other than as an aid to situational awareness.

 

[Palmpilot]

I guess that's a good question since if one equates "non-WAAS" with "non-approved" there's a basic lack of knowledge involved....

I think part of the problem is that AIM section 1-1-17b2(a)(1) is a little opaque without a fair amount of digging:

2. IFR Use of GPS

(a) General Requirements. Authorization to conduct any GPS operation under IFR requires:

(1) GPS navigation equipment used for IFR operations must be approved in accordance with the requirements specified in Technical Standard Order (TSO) TSO−C129(), TSO−C196(), TSO−C145(), or TSO−C146(), and the installation must be done in accordance with Advisory Circular AC 20−138, Airworthiness Approval of Positioning and Navigation Systems. Equipment approved in accordance with TSO−C115a does not meet the requirements of TSO−C129. Visual flight rules (VFR) and hand−held GPS systems are not authorized for IFR navigation, instrument approaches, or as a principal instrument flight reference.​

AIM Table 1-1-6 Note 1 is a little better, in that it at least it points the reader to "the AFM, AFM supplements, or pilot guides."

 

[midlifeflyer]

I think part of the problem is that AIM section 1-1-17b2(a)(1) is a little opaque without a fair amount of digging:

2. IFR Use of GPS

(a) General Requirements. Authorization to conduct any GPS operation under IFR requires:

(1) GPS navigation equipment used for IFR operations must be approved in accordance with the requirements specified in Technical Standard Order (TSO) TSO−C129(), TSO−C196(), TSO−C145(), or TSO−C146(), and the installation must be done in accordance with Advisory Circular AC 20−138, Airworthiness Approval of Positioning and Navigation Systems. Equipment approved in accordance with TSO−C115a does not meet the requirements of TSO−C129. Visual flight rules (VFR) and hand−held GPS systems are not authorized for IFR navigation, instrument approaches, or as a principal instrument flight reference.​

AIM Table 1-1-6 Note 1 is a little better, in that it at least it points the reader to "the AFM, AFM supplements, or pilot guides."

LOL! I don't understand that either. I'm, not planning on running through the TSOS. But there's enough other material on WAAS vs non-WAAS in the AIM and other publications that may not be particularly relevant to VFR pilots but is 101 level knowledge for instrument pilots. You can probably dive deeper than this but off the top of my head it comes down to

• LP capability with WAAS, with lower approach minima than LNAV.
• Official vertical guidance with WAAS – LPV and LNAV/VNAV approach capability.
• Advisory vertical ("+V") guidance on LNAV and conventional approaches with WAAS. Enroute too!
• Sole source enroute navigation. Non WAAS must have other equipment suitable for the route.
• May rely on approach at RNAV both destination and regulatory alternate.
• RAIM checks required without WAAS.

 

[coma24]

Is anyone else slightly saddened by the notion that someone has been avoiding airspace or shooting approaches because they didn't have WAAS? Glad it got sorted out. OP, you've been missing out. I spent around a decade flying IFR, filed as /G without WAAS.