GPS On The Cheap: Why Some Bargains Arent

Got a stone-age navigator in your panel in need of replacement? There are good deals on the used market for VFR boxes but IFR-certified units may be no bargain.

by Larry Anglisano

Weve had hands-on experience with panel-mount GPS for we’ll over a decade now, spanning an entire generation of small aircraft systems and then some.Its all surprisingly clear in our memory, dating back to Garmins semi-portable GPS 100, a modest launch product that sent the company sailing toward its current status as King of all GPS.

Although its hard to recall a time when Garmin wasnt the dominant player in avionics, the market was, nonetheless, more fragmented in days gone by.Bendix/King pioneered IFR GPS with the KLN90, a navigator that began life as the KLN88 loran. Remember Northstar, Trimble and IIMorrow, the latter morphing into UPSAT before ultimately being gobbled up by Garmin?

The point is that avionics choices werent always dominated by high-end boxes such as Garmins GNS430 or GNS530 series. We see hundreds of panels with older, perfectly serviceable navigators that, a decade ago, cost half what a new GNS430 does. The owners of these airplanes see no reason to upgrade these navigators to something more capable or more expensive. And theyre right. If the airplanes mission is modest occasional use, why break the bank on investing in the panel?

But there’s a problem. Suppose youve got an older navigator, say a Northstar M1 and it breaks. Can you get it fixed? Or should you replace it with a cheap equivalent used model? Or buy a newer GPS? Many mature or orphaned systems still remain in a fair percentage of the fleet, but are slowly getting dumped on the used avionics market, ultimately peddled by mail order salespeople or advertised in the classified section of Trade-A-Plane.

Newcomers to aircraft ownership who hunt for used and inexpensive GPS can easily get bitten by GPS dogs. In this article, we’ll coach the used GPS installation process while scanning some of the popular models found on the used market that could tempt a buyer looking for a replacement. You can also reference this information to decide whether to fix an old model.

The Long View
The used avionics market does strange things. Over some stretch of months, even obsessively budget-minded owners responding to unknown market forces suddenly invest huge sums on premium factory model airplanes or avionics.Just as suddenly, the market swings the other way, sending owners flocking to avionics shops to either install used equipment bought at a bargain on eBay or to pick through the shops inventory of displaced GPS. These market swings are great for the portable GPS market, which has proven to be an excellent alternative to VFR panel-mount GPS equipment, often winning the battle over panel mounts of any flavor or vintage.

Buyers will need the advice of avionics shops who are we’ll schooled in the repair habits of factories that still support a given GPS, if its supported at all. Still, most vintages of once-popular GPS units are supported by some entity, but the quality of the support will say a lot for the potential future of any box you have in mind.

The fact that Garmin long ago dropped the successful GX series of UPSAT navigators from their production lines-Garmin never actually manufactured the GX series, they just bought the company that did-signifies that long-term product support of these units might be questionable, in our view. We can say that support of the product at Garmin-AT in Salem, Oregon is still good.All the same, buying any used or new piece of avionics carries the risk of it becoming obsolete at any moment. To be sure, the used avionics industry has changed dramatically in the last year or two and FAA certification considerations are wholly responsible for most of it.

Not surprisingly, used GPS navigators take top honors in used equipment popularity, but only VFR units and basic installations will yield consistently inexpensive projects. If you want IFR GPS and wish to go the used route, the paperwork and certification alone might make the job uneconomical.

Older GPS models have been displaced into a new world of FAA certification procedures and this makes the process difficult and pricey for the shop and aircraft owner when it comes to repair and installation. (See the sidebar at right for more information.) What follows are our comments and observations on specific brands and models.

Used GPS hunters assume that they can buy an older Garmin GNS430 or GNS530 and save a ton over what a new system would cost. The used boxes are out there but they havent proven cheap to buy and this remains the case.Consider that a trip to the factory is often the only way to properly return a removed unit for service. The FAA says that for a shop to issue a Form 8130, it will need to have the capability to ensure that the unit meets original manufacturer specifications. In most cases, the factory is the only place that this can happen.

As we reported in the January 2006 issue of Aviation Consumer, flat rate repair schedules are the norm and for a GNS430 or GNS530 thats out of warranty, this will be $600 to $700, with freight and shop invoice tacked onto the factory bill. Earlier GNS430 systems operated only on 28 volts, so the installation in a 14-volt airplane requires a voltage converter, complicating the job and adding cost.

Dont expect a huge savings in cost for a used GNS430 or GNS530 over a new system, as sellers wont likely give these units away, given the strong market demand. This isn’t to say that reasonable deals cant be had on a used GNS430 if the voltage fits the application and certification paperwork is already in order. In general, expect roughly an $800 to $1000 difference in overall cost between used and factory new systems. To us, the factory warranty and support thats often lacking on a used box just isn’t worth this savings.

The picture is rosier if your requirements are more modest, say for a VFR-only navigator. Garmin GPS150 (discontinued) and moving map-equipped GPS150XL (current production) units are reliable and use the common GA56 antenna.While early vintages of the GPS150 (and comm-equipped GNC250 and GNC250XL) suffered power switch assembly problems, these units are solid performers and worthy of purchase on the used market, often for we’ll under $2000.

The GPS155 and GPS155XL and comm-equipped GNC300 and GNC300XL units are IFR-certified, requiring an OBS resolver-style indicator for IFR use. These are pricey indicators and add expense to an installation. Our view is that the unit cost has to be right to invest in a full IFR installation. Still, these navigators represent a good choice in used IFR GPS due to their reliability and current production status. Although they lack the capability of the GNS430/530 series, they may represent a better value for many owners.

The IIMorrow model 820 Flybuddy GPS was a popular seller in the mid 1990s, evolving from the 800 Flybuddy loran-C system. In fact, the Flybuddy GPS could be inserted into a Flybuddy loran installation after changing the antenna, but without any rewiring. The small LCD display was a wart on the unit and tough to read in sun-splashed panels. These units are known for losing their GPS almanac data, requiring a system date and time reset and satellite initialization. We mention this because if you buy one that has been sitting in a box for awhile, it will probably wake up with a blank stare during the first power-up. We wouldnt pay any more than $800 or so for this system, with an antenna and mounting rack and connectors. We wouldnt pay more than $300 to repair an already installed unit. (These are still factory supported, by the way.)

The Apollo 2001 GPS evolved from the 2001 NMS, which utilized a remote GPS receiver and self-contained loran receiver. Investing in a new installation for one of these systems is questionable given their age and promise for reasonable support. If one breaks, its still repairable and thats probably a better option than replacement, at least for now.

A better choice than the Flybuddy and 2001GPS would be the GX series of navigators, including the Apollo GX55, which was a direct replacement for the Flybuddy series and the earlier lines of IIMorrow loran systems. Maintenance matters include internal memory battery replacement, display repairs and bezel button replacements. Fair market value for a complete GX55 might be around $1000 to $1500 with factory paperwork and the latest software. It can be installed for enroute and terminal IFR certification, if connected with a CDI and annunciation, but it wont do approaches.

The GX60 is an IFR approach-approved unit with an integral comm radio. Like the rest of the GX line, including the commless GX50, it was dropped from production when Garmin bought UPSAT. As we noted, Garmins factory in Salem-the original IIMorrow and UPSAT factory-still supports the GX and Flybuddy line of GPS systems. But we wonder for how long. Installing a used GX box for IFR wont be cheap and is probably not worth the expense.

For several years, the used market has been flooded with KLN90-series GPS systems. Standard equipment in many Beechcraft models and once commonly retrofitted into corporate jets, the KLN90 has a reputation for being tough to program if not a reliable and rugged GPS.

We caution against buying these units for instrument students and others who might not be avionics-savvy. The KLN90 is the first and basic variant of the KLN90 series, which evolved into the IFR enroute-certified KLN90A and then the approach-certified KLN90B. Maintenance can get pricey on any KLN90, since the CRT display in these units carries a hefty replacement cost.Internal battery replacement can also be a time-consuming affair, but still doable on an avionics shop repair bench.

KLN90B systems can likely be had for we’ll under $2000 and like the Garmin GPSs, require a pricey OBS resolver-style indicator for IFR use. The same holds true for the KLN89 series introduced at the end of the KLN90B production run. The KLN89 is VFR-only while the KLN89B is a full IFR box found in newer Cessna models, as part of the Silver Crown Plus line of avionics.

Like the KLN90B, many users find the KLN89B to be demanding to program during the approach phase and for this reason, many are removed from the panel and replaced with the current-production color KLN94 GPS. The KLN94 slides into an existing KLN89B installation with little if any rewiring and uses the same antenna, too.

The KLN94 approach programming has been greatly improved over that found in other Bendix/King IFR units line and the procedure button, introduced on the Garmin GNS430, makes loading and activating approaches a snap. Like the GNS430 however, the KLN94 holds a high resale value on the used market, making it an unlikely choice for high-value GPS when shopping the pre-owned market. If you can live with the quirky architecture of the KLN89B software, it can be had for low prices-well under $2000. As one new owner recently learned, a trip to the Honeywell factory might prove to be costly, easily totaling $800, so pick one thats not likely to need repairs.

Other early to mid-production models include the KLX135 with what we consider to be a wishy-washy display that was difficult to read with a GPS receiver we consider a marginal performer. A KMD150 GPS is a reasonable VFR model, if there’s panel space to accommodate it. Dont expect to see many on the used market.

Northstar, Trimble, Magellan
Think hard before investing any money in installing and repairing these brands. The best chance for a successful used experience will be with a Trimble model, now being supported by Free Flight Systems in Texas. The Trimble 2000 Approach and one of the first oceanic approved units, the big-airplane-focused 2101, were successful products, but suffered rocky endings as a result of Trimble abandoning the general aviation panel mount market.

Free Flight systems still manufactures the 2101 Approach Plus, a Dzus-mount design GPS focused on corporate aircraft. Weve found that Free Flight Systems is an attentive company, returning phone calls promptly and offering reasonable repair turn-around and pricing.

We think the earlier Trimble products are dated, however, compared to other choices on the used market. They offer no moving map displays and ancient software architecture.

Canadian-based CMC Electronics has taken over the repair and overall support for the line of Northstar GPS units and owners weve spoken to have mixed feelings about their support. The company charges a flat-rate evaluation fee of $250, billed to a credit card before any work is accomplished. The $250 is applied to the actual repair if the customer decides to proceed. We recall one customer who waited almost two months for his M3 unit to be returned, only to learn that it had been put on hold for non- payment, despite his credit card getting billed. This nearly severed the relationship between him and his shop and CMC didnt intercede to clear things up. For this reason, we cant recommend the installation of any Northstar GPS product and we think repairs on these old boxes are iffy.

Magellan? Forget it. Youd be hard pressed to find a shop that would install an old 5000 series Magellan panel mount for lack of complete support. Magellan shines bright in the civilian portable world but its aircraft products are history. If your old Magellan packs it in, say goodbye and look for a newer used box or a low-end new product, if your budget doesnt allow a GNS430 or GNS530.

Our top pick for used GPS to replace an older box thats no longer repairable is the approach-approved Garmin GPS155XL. There’s no question of continued long-term support, since the unit still maintains a slot in the current product line and these navigators have proved reliable and rugged. While the approach and procedure programming logic is second generation and not quite up to the level of simplicity found in a GNS430, it shouldnt be a struggle for new students learning GPS procedures. Making the transition from the GPS155 series (or GNC300) to a GNS430 should be reasonably easy, since they both use the GA56 antenna and a resolver-style indicator. This allows future growth potential, in our view.

The VFR GPS150XL (and GNC250XL) might not be a spectacular used market bargain since the prices on new units are reasonable– street value of around $2600 and $2900. Used units might bring close to this. We think that Garmin support is the best in the business and priced fairly, so owners shouldnt fret future support. We also believe that the GPS150XL represents an excellent value if purchased new.

We think that state-of-the-art portable units such as the Garmin GPSMAP396 with XM-based Weather and XM Radio features might be an attractive alternative to repairing any panel-mounted VFR GPS and from what we see, owners agree. As noted the sidebar, used portables are also an attractive option. While portable units cant legally be interfaced with autopilots, they can be equipped with ships power and mounted on a panel. See the sidebar for more on this.

Also With This Article
“The IFR Certification Trap”
“Used Portable or Panel Mount? Garmin’s 196 Is Unbeatable”

-Larry Anglisano works at Exxel Avionics in Hartford, Connecticut. He is Aviation Consumers avionics editor.