Caveat Emptor: Used GPS Navigators

There has always been a lively market for used avionics and for the buyer who doesn’t do the homework before plunking down hard-earned dough, there’s a lot to lose and in the long run you can end up spending more than what you would have spent for new gear. And so it goes with used GPS navigators, where it’s very tempting to shop the market for preowned models in hopes of saving money. That isn’t a bad idea, actually.

Considering that Garmin’s flagship GTN 750Xi is $20,995 and Avidyne’s top-of-the-line IFD 550 is $21,889, it makes sense to at least see what you can find on the used market. Here’s a guide to follow so you don’t get stung.

Installation

Before even lifting a finger to surf the used avionics listings, forums, and other sources, the first thing to consider is where you’ll have the system installed. My advice for buying used avionics has always been to start at a trusted shop. First, the shop might have a unit you’re looking for and if it doesn’t, it might know a reliable source. Shops are pretty particular about the stuff they install (some might even refuse to install used equipment) because they don’t have time to deal with faulty equipment, plus the shop knows what it will need to put the system in. Not having the right hardware means schedule delays.

For example, you might find a smoking deal on a used Garmin GTN navigator only to realize that it doesn’t have an antenna, a complete installation kit, or even the right regulatory paperwork needed for installation. For used GPS navigators, you’ll need a fully functional antenna that’s compatible with the receiver. Not all satellite antennas work with all WAAS navigators, and because most modern navigators worth buying have an IFR TSO (TSO-C129(A1) for non-precision approaches, and TSO-C146 for standalone WAAS units, the antenna has to be one that’s approved under the STC. Also worth thinking about: Antennas live hard lives out in the elements on top of the aircraft cabin, so chances are the one that comes with your used unit will be weathered. The shop should be your guidance, but it could make sense to simply source a new antenna—especially if your bird sports a decent paint job. Do you really want to install a beat-up antenna on a new paint job?

As for the installation kit, most shops will want a complete one or you’ll be charged for one. Used models might come with some of the install hardware—maybe the mounting rack, backplate, and connectors—but you should find out exactly what will come with the unit, have the seller send you images of the kits, and then show them to the shop. Installation kits are expensive, and you should demand that used units are supplied with complete ones.

As for the physical installation, consider the interface. IFR navigators must be connected with a CDI (or EFIS) for displaying GPS course data, and aircraft that haven’t been upgraded in a while likely won’t have a compatible CDI. Garmin’s current GPS-only slim-line navigators (GPS 175/GNC 355/GNX 375) are compatible with a variety of third-party indicators, but older navigators with an OBS course resolver require specific indicators. Garmin’s GI 106 series is a popular choice, but it’s priced over $1,000 on the used market. This extra cost makes a budget EFIS more appealing.

Salvage Dealers, Certification

Selling avionics that were removed from wrecked airplanes is a big business and in general, there’s nothing wrong with sourcing some avionics from reputable salvage dealers, including GPS units, with some important caveats. I’ve seen plenty of wrecks sit for long periods of time out in the elements before the electronics were removed, and that means moisture could be a concern in some climates. Any piece of avionics that went swimming is off-limits—you don’t want these. Impact damage is obviously a deal-breaker, too.

Consider traceability. Avidyne’s policy is that it won’t repair or issue return-to-service paperwork for any unit that’s been in an accident—even if it was a gear-up landing—because it says it can’t verify hidden damage. But even salvage dealers should be able to provide the appropriate regulatory paperwork that gives an installer the green light for putting the GPS in the airplane. Forget the “yellow tag” ads that tag along with used equipment. This is old marketing speak. Most manufacturers (and FAA repair stations) will provide an 8130-3 after reconditioning or remanufacturing a component to original specifications or after testing the unit to manufacturer’s specifications.

But consider if you source used GPS from an end user, it might not have any airworthiness documentation at all. Plan to pay for bench time, which can be as much as $150 per hour. Some avionics shops might be able to do basic function tests of the GPS, including making sure the receiver works, the display is in good condition, and other basic functions. But it might not be able to test the unit as the manufacturer can. Which brings up a hidden trap in the world of used GPS navigators: flat-rate factory repairs.

It Costs How Much?

Factory flat-rate repair pricing can kill what seems to be a good used-market deal in a hurry. Let’s start with a controversial topic and the Garmin GNS navigators—which have always been hot used-market sellers. But that has slowed since Garmin announced it can’t provide support for units with failed LCD displays. Garmin’s Service Advisory 23018 Rev B says that display repairs for the WAAS and non-WAAS 400-series navigators are no longer available and have been discontinued. The advisory goes on to say that other repairs for both WAAS and non-WAAS 400-series navigators will continue to be available for as long as possible, but that alone should be reason to think twice about spending big for a used GNS navigator. And you can spend big, especially if a factory repair is involved.

If it goes back for repair and Garmin finds that the GNS 430’s display is faulty, it charges a $500 assessment/handling fee to return the unit back to the customer, unrepaired. But if the display is functional per Garmin’s specs, the flat-rate repair cost for a GNS 430W is around $2,000 and around $2,400 for the GNS 530W. This covers typical wear-and-tear items like bezel keys and knobs, display lenses, and other routine work.

At press time, I searched the market for used GNS 430W units and found plenty that were typically priced around $5,000. The reputable Sarasota Avionics in Florida was advertising a complete GNS 430W system, including mounting rack, backplate, connectors, database card, and a GA 35 WAAS antenna, for $5,589. It offers a 60-day warranty and the unit is shipped with a current FAA 8130-3 form. There were a variety of other GNS 430W and 530W units for sale, some on Facebook forums, and many were in as-removed condition, advertised as functional, and priced from $3,500 to $6,000. Again, proceed with caution and add the potential for a factory repair to the price to be safe. And there are plenty of scams—don’t send money ahead of time unless you are comfortable with the seller.

I think it makes good sense to source used navigators (and other avionics) directly from avionics shops. They have traceability, can issue the right regulatory paperwork, know what install hardware to include, and will be easier to deal with if you needed warranty support—which is typically 30 days for used gear, though sometimes it’s 60 days. Shops that install a lot of the Avidyne IFD navigators, which are direct replacements for the Garmin GNS WAAS units, have generally been a good source for used GNS 430W/530W units and might be the safest bet given the risky problem of a failed display. But there’s still risk. As for used Avidyne IFD navigators, there just aren’t many around because owners don’t remove them.

Units to Avoid—And Ones That Don’t Make Sense

I wouldn’t touch any GPS navigator that has no support, including older UPS-AT (Garmin-AT) GX-series navigators, GPS 150/155XL/GNC 300 units, King KLN88 navigators, and even older KLN90-series units.

But what about current-production models, including the flagship GTN 750Xi, GTN 650Xi, and the GPS-only Garmin GPS 175/GNC 355/GNX 375 navigators? I can’t see any reason why most owners would remove these units and if they did, you can bet the selling price would be close to what you’d buy a new unit for—while getting a two-year warranty.

Last, talk to your shop before buying anything. Some shops don’t like installing equipment that customers carry through the front door. It cuts down on their profit, can mean extra work, and in the end it just might not be worth it for you or the shop.