Garmin IFR Navigators

There's no doubt that pilots love Garmin's IFR navigators. Most of the airplanes in my flying club's fleet have Garmin GNS 430s or GTN 650s. They're easy to use and bullet proof.

I've seen many of the newly completed E-ABs include a GTN 650 to fulfill the IFR navigation role. On occasion, some homebuilts sport the larger GTN 750 or an Avidyne IFR navigator of competing sizes and functionality. Even some of the more cost conscience panel are using available GNS 430/530 configurations.

I've given some thought to the role an IFR navigator would play in my Sling TSi panel. From an initial configuration perspective, an IFR navigator is not needed when the plane rolls off the production floor (that is, out of my garage). Certification and flight testing would involve no IFR use, and in fact, I wouldn't fly the plane IFR until it has at least 100 hours on it, maybe more.

So, what's my problem this time?

I find it interesting that the dimensions of the GTN 650, 635, & 625 cases are identical. Their weights are published as 7.0, 6.2, and 5.4 pounds respectively, so it appears the insides are different, as would be expected. I also find it interesting that each model is 8 tenths of a pound different from the next model regardless of the additional radio technology.

I bring this up because Sling builders have written about the need to modify the subpanel in order to fit the GTN 6xx and I wonder why Garmin made them all the same size. Perhaps Garmin's intention is to allow for slide-in upgrades between the 6 series and future offerings? Perhaps it is easier from a production/cost perspective to use the exact same form factor?

Whatever the reason, the large depth dimension of nearly 12 inches can be an inconvenience for some builders whose airplane designs typically accommodate smaller, modern avionics. We don't need a GPS navigator to fly IFR, but this where approach, departure, and en route systems are trending.

Cost Estimates

A couple of weeks ago, Barry Jay from TAF USA sent me the Sling TSi kit price list. Since then, I've been working out cost estimates, build schedules, and cash flow timing to coincide with the build schedule. I think I have it all worked out now, but I'm not getting into those details here.

The estimated price with factory options and without paint, avionics, or tools is $119,227. Since I'm lucky enough to reside in the great state of California, add to the base cost another $8,942 in sales tax for a grand total of $128,169. This does not include shipping, but I live only 90 minutes away from Torrance and I have a big truck.

My truck being used as a Halloween prop

The factory options I selected include dual toe brakes (because my feetsies need two more things to do and my hand need one less), factory interior (nicest in the market), the firewall forward package, and the electricals kit. The price also includes strobe/nav/positions lights, but it doesn't include the ELT. I am not, nor will I ever, select the BRS option. I'll post more on that another time.

I figured the tools I'll need will come in under $2,000 and the paint (or wrap) that I do myself about $2,500. With avionics (and more CA sales tax), add another $10,000 to $35,000 to the overall price.

My objective is to cap avionics at $21,000. This likely eliminates an IFR navigator on the first pass, which actually puts the project in a position to lose a chunk of money at some point. For example, the Sling will require ADS-B out and that will require a compliant GPS source. In the Garmin universe, this is a GPS 20A ($845) and a GA 35 antenna ($309) and miscellaneous install components ($60). That's about $1,100 in equipment that would go away when an IFR navigator is introduced. An upfront option to consider is to buy a used one and then re-sale it.

Finally, factoring in a few miscellaneous items, an all-in cost under $160,000 would be desirable. Boy, it adds up quickly.