Both the GNS430 and G1000 are/were available with and without WAAS, and I believe it's even possible to upgrade a GNS430 to add WAAS support. When I get into an unfamiliar rental aircraft, is there a quick and easy way to see if WAAS is available, by checking the avionics themselves? Is anything physically different about the units, is there some properties/status page I can check, or is there something different on the display?

Obviously asking the operator and checking the aircraft handbooks would be the right thing to do, but sometimes that doesn't work out, e.g. the FBO's instructors are all out flying and the admin people just don't know.

  • $\begingroup$ You're right about the upgrade - they replace the core, antenna, and possibly CDI, but the faceplate can read GNS430 even if the device itself is a GNS430W. $\endgroup$
    – egid
    Commented Apr 27, 2015 at 20:11

2 Answers 2


NOTE: as pointed out in the comments, none of these quick verification steps actually guarantees that the airplane you clambered into is certified for LPV approaches, or for IFR GPS usage at all!

On boot, a 430W will display that it's a 430W:

Garmin logo loading screen with model number

Aside from that, I'm sure there's a version info screen somewhere (on both G1000 and GNS430), but the best solution I can think of is to check the satellite status screen. I'm trying to find examples of a 430W displaying it, and failing, but on a G1000, you'll see this:

G1000 screen with GPS info

If the G1000 supports WAAS, it'll display that under the 'SBAS Selection' header and you'll see satellites at the bottom numbered in the 100s - 124, 126, 129, etc - all the 100-series satellites are the WAAS augmentation satellites. The satellites augmented by WAAS will also have a "D" at the bottom of the signal strength column.

  • 5
    $\begingroup$ Note that just because a particular receiver has WAAS capability, it does NOT mean that the entire system/installation is certified to use it. The only way to know that is to look at the AFM and see what it is approved for. $\endgroup$
    – Lnafziger
    Commented Apr 27, 2015 at 19:56
  • $\begingroup$ Interesting, I hadn't thought of that. From a Part 91 GA standpoint, what would a non-certified WAAS install look like? CDI not capable of displaying the right info? $\endgroup$
    – egid
    Commented Apr 27, 2015 at 19:57
  • $\begingroup$ Whether it's 91 or not, it could be in the panel but (just to make something up) maybe the antenna is not installed according to a "certified/approved" installation. In this case, it may still work, and it may even still be accurate, but it isn't guaranteed to be under all circumstances that are evaluated during certification. (Maybe if you fly in the rain it will quit providing data, or in icing, etc, etc.) It could also be that a particular component is "good enough" for standard GPS but not WAAS, and while the receiver is certified for it, the installation is not. $\endgroup$
    – Lnafziger
    Commented Apr 27, 2015 at 21:00
  • $\begingroup$ Note also, that it should have a placard which says "VFR ONLY" if it isn't certified for IFR flight. There is no way to know that it is "missing" (maybe it fell off, maybe it was never installed, lol) if it isn't there though unless you check the AFM. $\endgroup$
    – Lnafziger
    Commented Apr 27, 2015 at 21:04
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    $\begingroup$ Try the POH then! ;-) $\endgroup$
    – Lnafziger
    Commented Apr 27, 2015 at 21:10

For the 430: use the outer knob to scroll to the AUX group. On page 4 (setup 2) there should be an item called SBAS SELECTION. If there is, it is WAAS equipped, however, verify WAAS is ON. Similarly, if on the NAV group you scroll to the satellites page they will display as green rather than blue. But like before, verify WAAS is ON in the 'Setup 2' page of the AUX group.


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