All this Garmin stuff from Vans

[guycole]

What avionics are you buying for your RV? How did you run down all the details?

I have a few starter questions.

For example, what is the purpose of a multifunction display (like a MX-20)? I see a approach plate is displayed in the sample pictures. The supporting GPS (like a GNS-530) does not display approach plates?

I also note that the GNS-530 transmitter is only 10W. This sounds quite anemic to me. Does anybody know what the transmit power for a KX-155 is? I like my current Kings and if 10W is comparable then I would be happy.

How about ILS/LOC/VOR support by the 530? I think the GI-106A operates like a normal CDI (i.e. VOR/LOC/GS). This isn't solely GPS driven, right? It can work like a normal nav so I can still do a legal precision approach?

And does anybody know how much the Jepp updates cost?

[Spike]

Here's my take.

What avionics are you buying for your RV? How did you run down all the details?

Dont know yet, but if I were doing it today it would be centered around a G430 or G530.

For example, what is the purpose of a multifunction display (like a MX-20)? I see a approach plate is displayed in the sample pictures. The supporting GPS (like a GNS-530) does not display approach plates?

A MFD does two primary things. The first is to give you a bigger prettier display. The second is to integrate multiple pieces of information from different pieces of equipment into the same display. Its not like each piece of equipment procduces a video out, typically they produce information and describe where that information is. (ie lightening strike here). The MFD takes all of that data and overlays it onto one picture. For instance you can take storm data or radar data, plug it into the MFD, and have it overlay that data with information from the GPS, weather system, etc. Some GPS will do this to some extent. For example the garmin GPS' will take TIS information and weather information (from their other garmin units) and overlay them. They wont do this for all types of data though. The garmins do not display approach data as the MX20 does. BTW, I've been behind the MX20, its a very very nice unit.

I also note that the GNS-530 transmitter is only 10W. This sounds quite anemic to me. Does anybody know what the transmit power for a KX-155 is? I like my current Kings and if 10W is comparable then I would be happy.

I have both a new KX-155 and a new GNS-430, both of them are crystal clear and good radios. I wouldnt sweat it.

How about ILS/LOC/VOR support by the 530? I think the GI-106A operates like a normal CDI (i.e. VOR/LOC/GS). This isn't solely GPS driven, right? It can work like a normal nav so I can still do a legal precision approach?

The GNS-530 is both a GPS and a NAV/COMM. The GI-106A interfaces with the 530 unit and can be driven by either the GPS or the NAV. (In the Garmin units, the radios are actually seperate units in the same box, sharing the same screen). There is a button on the bottom left of the Garmin units called "VLOC" and it allows you to select what you want to drive the indicator, the VOR/ILS or the GPS. The screen on the unit tells you what is selected as does the 106 indicator.

The Garmin boxes are in my opinion very very good units. There is a reason that they have sold and are still selling like hot cakes. They also don't lose their value once installed as much as other units. When we refitted our 172 I wanted an all King panel but lost out in my partnership. Frankly, Im glad that I did. Having flown with both a KLN-94 and a GNS-430, Garmin all of the way for me.

And does anybody know how much the Jepp updates cost?

I dont know about Jepp, but we did the update thing from Garmin and I remember it to be pretty pricey. Since we dont fly the airplane IFR right now, we stopped the updates as the major airports/land marks/waypoints dont change. The things to verify are frequencies that change and airspace. Most everything else in the updates seems to revolve around IFR approaches & airways.

Someone might be able to better answer some of the technical questions regarding the specific units and the way that MFD's work. I will vouch for the Garmin units though. I have been very happy with ours.

-- Spike

[guycole]

Very interesting.

I fly a fair amount of "light" IFR - no ice for me thank you. I commute to work in the San Francisco bay area in my Cherokee which routinely requires a climb/descent through the marine layer. Today I do it the old fashioned way (no GPS, government approach plates, etc).

I think I would like the moving map and TIS. I don't mind paper approach plates except they can be hard to read in the dark.

The RADAR/StormScope option is interesting. Do you know what units are supported? I saw this mentioned on the Garmin web site but didn't see any specifics.

Also, what autopilots interface to the Garmins?

[Spike]

I do not believe that the units that display the approach plates negate the legal need for paper ones. There seems to be some debate regarding this lately and I think that as of now the FAA has said you cant count that. More investigation should be done though.

I dont know what kind of RADAR/Stormscope is supported as I have to say that I havent researched it. I do know that you can get NEXRAD through some of the weather services that do interface with the GARMIN.

As for autopilots, I *know* STEC does. We were contemplating a system 30 with alt hold and GPSS for the 172, but we came to our senses. I think Trutrak can give you GPSS for the garmins. But Im not sure. Check on the new Builder's resource pages as I have most of the autopilots for homebuilts listed there with their sites. Im pretty sure you can get your questions answered there.

-- John

[mustang]

Yes, I have been doing a lot of homework lately on this. Also, I have considerable experience with glass having the 747-400 and 767-300 on my licence. MFD's are screens that not only can be overlayed with radar and TCAS information ontop of your moving map display, but they can be used as the PFD or the EICAS also if required. (Pilots Flight Display or Engine Indicating & Crew Alerting System) So the screen that is normally used for the AHDI, can be used for the Nav Display or the Eicas display.

Grand Rapids Technology has a fairly inexpensive screen like this that can also be split for AHDI and Moving Map or EICAS, any two out of the three or, any one of the three. This is even more wonderful than the Boeings, but of course they are now old technology.

Getting back to some of the original questions, a ten watt transmitter is quite powerful. The old standard used to be 5 watts. Consider that the aircraft signal does not have to go around buildings or terrain, it is "out there in the open 90% of the time. So 10 watts is lots.

The other question seems to be about GPS/Autopilot compatability, I think. Typically, GPS units will output one of two formats, AVLINK and NMEA 108 datastreams. Most autopilots can read one or both of the outputs. A few wrinkles show up though, in the the NMEA format which may not be according to the autopilot protocol. In other words, the NMEA datastream is supposed to be in a certain sequence of information, but some portable NMEA streams have slightly different characteristics. Some portables do not support any output, but the newer Portable Aviation GPS units typically do. Find a GPS that you like and then download the entire Operating Handbook or browse it online. Research the datastream format and record it. Contact your choice of Autopilot manufacturer and request a compatability report on your chosen GPS. I did this yesterday with the EZ Pilot to be matched to the Lowrance 2000c Airmap GPS. The answer was yes and so I ordered the unit. When I ordered, it was a different person that originally Oked the matchup, and the fellow requested the type of aircraft, the type of GPS and I got the feeling that they would load the autopilot software to accomodate the Lowrance NMEA output which they are familiar with, and specify the correct servo for the type of aircraft.

Technology is progressing so rapidly in this field that you could probably study nonstop and still be a bit behind. It's kind of like digital cameras, or desktop computers, the next kid on the block is always better and/or cheaper, but just jump in when you are ready and take what you get. Compared to what was out there ten years ago, we are lucky boys and girls! Consider that for about four thousand dollars, you can have a moving map GPS coupled to your autopilot that will fly a multi leg flight plan from just after liftoff to just before touchdown with just the touch of a couple of buttons. All you have to do is manage the the throttle, prop pitch and mixture, Oh, and watch the scenery. To put this all into perspective, consider that just the windshield on a Boeing will cost more than the price of an entire RV.

Cheers, Pete