New garmin WAAS units: 430w/530w

[kwmoore]

I'll be getting a GNS530w in my new 260se Katmai, so I downloaded the introductory video from the Garmin 530 product page (http://www.garmin.com/products/gns530/) that describes functional differences between the 530 and 530w units. It's a ~50 MB wmv file, so it may take a while to download.

Really interesting! There are a number of additional capabilities in these units; for example:

A terrain page is standard

One can program in an offset parallel track for enroute legs of one's flightplan; for example one can fly 1 (or any other distance out to 99) nm on either side of the flightplan leg. This would be very useful while VFR for avoiding restricted airspace, or perhaps remaining out of the way of IFR traffic on airways.

The unit can now direct an autopilot/GPSS to fly holding patterns and holding pattern entry legs (parallel, teardrop).

The 430w/530w provide glideslope information on LNAV/VNAV and LPV approaches. These approaches flown in LNAV/VNAV mode usually have lower minimums. I still need to find out whether I would need additional authorization of some kind to fly an LPV approach.

There are also some minor procedural differences when flying approaches. The use of the SUSPend function is different and you can screw up an approach if you're not aware of the difference.

CDI sensitivity on a missed approach is now 0.3 nm instead of 1 nm.

Pretty neat! Quite a good value I think for the few kilobuck extra cost. :)

[LEVON HOPKINS]

Kevin, during my recent BFR, the examiner show me how to use this "parallel" feature for holding patterns on the regular 530. As I remember, he set the course deflection scale located at the bottom to 1nm then stated: "at 90 knots use 1.3 on the outbound leg as the distance to be used for the turn into the inbound course and usually do the intercept on the 1.3 NM as indicated when you exceed the 1 nm scale deflection. For 120K, use 1.5 for the parallel course." We did two and I'll be doing more next week to "learn" his systems. PS: he was one of three pilot advisers to Garmin on their 430 and 530 according to "him." Levon

[kwmoore]

I've now flown my new Katmai about 80 hr since pickup at the end of October. The new panel is great and I have had zero problems with it or with anything "Peterson" on the plane.

There have been two minor squawks: the JPI electronic tach experienced some manufacturer-related issues (had to be installed/removed 3 times!) and the HID taxi light (or its power pack) failed after some particularly moist California weather. It's under warranty so it shouldn't cost much other than labor to fix or replace when I get around to it. None of this resulted in any cancelled or delayed flights.

I like the dual 430w and am glad I installed them. I have done some practice LPV approaches and I must say it is neat to have the glideslope and lower minimums; also the STEC30/GPSS combination can fly the entire approach from procedure turn through missed approach and hold. One feels like one is playing a video game rather than flying a real plane! :cool:

However, I have yet to go anywhere that I couldn't have also gone just as efficiently with the original vanilla 430. Thus if I had "legacy" units in my plane I probably would not choose to upgrade to WAAS. Of course, I fly mostly VFR with occasional light-medium IFR in benign California weather. I might sing a different tune if I flew in the midwest or east.

[witrakw]

I have had the 430W upgrade now for about 6 mos. I'm sure I don't use it to its fullest capacity(neither did I the 430). The WAAS is remarkably accurate. The vnav glide needle is solid. In VFR, you can fly it to the pavement and it appears to be dead on . The biggest help to me with the Vloc is that it mostly removes the need to monitor step down fixes with a gps approach,,especially when it is turbulent, my brain cells are getting rattled too much, and wings level is enuf of a task.

On a different note, I never paid much to gps altitude vs. baro altitude on my previous 430. My previous MX20 had manually inputted baro corrected altitude, so it mostly matched my altimeter. Only when I swapped out the mx20 for the gmx200 which reads directly off the 430w for its altitude was I surprised at how much altitude difference there can be between baro pressure and gps altitude. The difference can be as much as 500 ft up to 7000ft on the altimeter(haven't checked higher). I initially kept asking my electronics install guys if the unit was reading correctly; after talking with Garmin reps and checking the gps altitudes with a handheld unit....the seemingly large altitude diffs are real and the higher you go, the larger they get. Pretty much a linear scale up to 7k. The altimeter and the altitude encoder transponder readout always correlated,,,,and similarly the 430w and my garmin96c altitude readouts correlated. Sounds like future ATC separation systems will have to rely either on altitude encoders or gps altitude, but not both.

[kwmoore]

Sounds like future ATC separation systems will have to rely either on altitude encoders or gps altitude, but not both.
I wouldn't be surprised if it's GPS altitude, with backups in place to fall back on the standard "29.92" baro altitudes in the flight levels.