Cost of WAAS

[Paul]

Does anyone have an estimate for the cost of converting a G1000 XL without WAAS to a WAAS capable plane? I understand you need to replace the GIAs plus also the MFD. Anything else I’m missing? thanks.

[mhoran]

When I did the upgrade, the going rate for a pair of GIA-63Ws was somewhere around $13-15k. I wouldn't spend any more than $15k on used units, but if you can get them for that price or less I'd go for it. The actual upgrade cost $1000. This included one additional antenna ($371 each) and 5 hours of labor (swapping antennas and loading new software.) This was all done in about a day, though I was down for weeks due to other work. I had everything done at SouthTec Aviation. Diamond does require (strongly recommend?) you get the upgrade done at a service center and I'd back this up as there have been reports of issues for people who had this work done elsewhere.

Edit: also, you do NOT need to replace the MFD. The original MFD will work fine, but you will not be able to fly coupled vertical navigation descents. However, you can fly coupled glideslope/glidepath just as before the upgrade. You'll need to manually set a descent speed / rate to fly any descent prior to the FAF.

[CFIDave]

The issue with 2007 DA40 XL models is that -- while including a GFC 700 autopilot -- the autopilot buttons on the MFD bezel are missing the VNV (Vertical Navigation) button. So if you want to enable the GFC700 autopilot to fly VNAV descents (or portions of many approaches that use VNAV prior to the FAF), you'll need to replace the MFD as well as pair of GIA63s.

To me, that's just as important as being able to fly LPV approaches with WAAS.

[mhoran]

I would argue this is a nice to have and not a necessary feature, nor is it specific to WAAS itself. We've already hashed this one out pretty in depth elsewhere, but to be clear, the MFD upgrade is not a requirement for the WAAS upgrade, it is completely optional per the STC. I haven't really missed the functionality myself. Programming in a 500fpm descent with the VS button is pretty simple. Coupled approaches themselves, past the FAF where it really matters, work fine with the APR button pushed.

[CFIDave]

While I agree that VNAV is not necessary with WAAS (in fact 2004-2006 DA40s with KAP-140 autopilots can't get VNAV after upgrading to WAAS GIA63Ws), IMHO it's almost a waste to have a wonderful GFC700 autopilot that can't fly VNAV.

I actually use the VNAV autopilot functionality many more times than I use the GFC700 to fly LPV glide slopes -- anytime the G1000 shows TOD (Top of Descent) and BOD (Bottom of Descent) along my course. You can always hand-fly the flight director guidance to achieve the proper descent, but you can't just program a 500 fpm descent rate into the autopilot to obtain the proper slope. For example, last week I was cruising at up high and given a crossing restriction by ATC; they wanted me to descend and cross a GPS waypoint at a specific altitude. Because of a 50 knot tailwind, VNAV descended the plane at more than 1000 fpm to make the restriction.

And even when flying VFR, I routinely use the G1000's Along Track Offset function with VNAV to have the plane automatically descend to pattern altitude 2 miles before reaching my destination airport.

[Paul]

And even when flying VFR, I routinely use the G1000's Along Track Offset function with VNAV to have the plane automatically descend to pattern altitude 2 miles before reaching my destination airport.

Without this feature, I would never know when to start a descent.

In all seriousness though, the primary reason for wanting the feature is that when my son gets his pilot license, I would like him to be able to help me fly the M600 and VNAV is more important in that plane. Anybody know what the MFD replacement costs?