Used Avionics

With few exceptions, on the used market, Bendix/King gear rules. As owners upgrade to color mapcoms, there are deals galore.

When the stock market goes down the tubes, so does the potential for aircraft owners to spend insane amounts of money on the latest and greatest avionics. No surprise that weve noticed a definite cooling in the avionics buying frenzy of two years ago. While modern gear adds new potential to an otherwise ho-hum panel, the ongoing replacement cycle also creates opportunities for good deals on low-time and capable pre-owned avionics.

In fact, the used market is so fluid and rapidly changing that we find it worth doing periodic reports on the state of play in used boxes. Theyre a great way to get a capable panel on the cheap.

Audio System First
In the not-too-distant past, owners who dwelled in the used avionics market tended to grab up the odd navcomm or upgraded ADF. In those cases, an old audio panel or even a simple switching network was up to the task.

Not anymore. These days, you can get first-rate, albeit older, electronics on the used market so, in our estimation, an audio panel should be high on the list of used upgrade considerations.

You neednt go crazy with multiple music inputs and cellphone interfaces, but don’t overlook the importance of system integration as it relates to audio. For example, some older audio panels arent equipped with speaker amplifiers. This could be a problem if the navcomm doesnt have an integral amplifier.

Our top pick for bulletproof used audio is the Bendix/King KMA24. This panel comes in several flavors as some are equipped with an HF option, airborne telephone feature or cabin PA announce. All of the KMA24 variants have integral marker beacon and, most important, this panel has proven to work with virtually any used navcomm.

We would warn against the Bendix/King KMA26, a product with a short production run that was scrapped after multiple problems relating to its built-in intercom and marker beacon. Weve seen a few of these units on the used market as many owners dumped them in favor of the newer KMA28.

Other choices in used audio include the Bendix/King KA134, a simple switch panel with audio amplifier but no marker beacon. It provides speaker/phone isolation as we’ll as switching for two transmitters. The Bendix/King KMA20, differentiated from the KMA24 by its toggle switches, is the progenitor of the KMA24. Lots of these out there, too, but they arent recommended due to age, serviceability and audio quality when loaded with multiple sources.

The same is true for the Narco CP135/136 series. Not a great match for modern stuff, in our experience. With owners pulling out Collins MicroLine avionics from many 1980s vintage Beechcraft, there are many AMR350 series audio panels to choose from. These are similar to the KMA24 and although the MicroLine series was taken over by S-TEC a few years ago, it has recently been dropped. Future support for MicroLine equipment is iffy.

As we see it, there really arent many choices in used navcomm upgrades. You should consider the following when searching the used market: a 720-channel comm; 760-channel is better. A 360-channel radio should be considered as a boat anchor, not even as a back-up.

Second, consider glideslope options. This gets tricky for the novice shopper and you could get stuck with something that can cause installation headaches. Older series navcomms from Cessna/ARC, Narco and Bendix/King utilized remote glideslope receivers, meaning the actual box that receives and interprets the glideslope frequencies is remotely installed.

So you have three components to install; the navcomm, the glideslope receiver and the indicator. Installation costs can get spendy and if youre buying somewhat dated technology, keep this in mind. Although once acknowledged as the industry leader, the Bendix/King KX170B series of navcomm uses remote glideslope technology.

Owners looking for a reliable and relatively inexpensive back-up navcomm could consider the KX170B or the later model KX175B. If modd to the latest standards, these units provide 760-channel communications with 200 nav channels. The accompanying VOR/LOC indicator of choice is the Bendix/King KI208 converter indicator.

There are an abundance of KX170B series navcomms available and this could be the most inexpensive alternative for back-up. But if you want glideslope, the story changes because of the remote boxes. The KN75 or older KN73 remote glideslope receivers and KI209 or KI204 indicators are the best way to provide glideslope to a KX170B. Although reliable, component costs put this option on the ragged edge of cost effectiveness.

The 170 series replacement-the Bendix/King KX155-is still current production. With its gas discharge digital display and integral glideslope receiver, a used one of these is probably more cost effective than the multiple-piece KX170B system bought at a fraction of the cost. The digital KX155 with its flip-flop frequency feature is both modern, reliable and less expensive to install.

Its tricky shopping for these boxes, however. The KX155 comes in multiple variants many of which may seem like a decent deal but may not fit your airplane. Be sure the unit voltage matches the airplane, 28- or 14-volt. Be sure it matches the aircraft audio system, too, as some earlier models had no audio amplifier. And make sure it has a glideslope, if you want that capability.

All KX155 units will support integral glideslope but the addition of the glideslope circuit board and hardware costs about $1500, thus a seemingly low price on a KX155 is usually indicative of a non-glideslope equipped rig.

The KX165 is the KX155s big brother, with its integral VOR/LOC converter board necessary to run an HSI. A digital VOR radial readout is an added bonus in the KX165. But unless you have an HSI, there’s no point in buying one of these, given the higher purchase price.

The budget Bendix/King KX125 is capable of operating with or without a remote indicator with its digital CDI integrated into the display. Speaking of displays, the KX125s is not very good, in our opinion. Black-on-gray LCD has never been a good idea for aircraft electronics. Sunlight readability, especially behind sunglasses, is poor at best and grows worse in a hot cockpit.

The KX125 will support a remote glideslope receiver and appropriate remote indicator but adding these components puts its installed price in the range of the KX155. Thats a no-brainer favoring the KX155.

The Narco MK12D navcomm shares similar design features with the KX155, with models with and without glideslope and in different operating voltages. The MK12D with ID825 indicator is the glideslope system while the MK12D with ID824 indicator is VOR/LOC only.

These units are reliable and worthy for primary or secondary systems but Narcos repair practices have agitated a good percentage of their owners. Narco got tough a few years back and as an incentive for dealers to sell the somewhat outdated line of Narco equipment, they basically said sell a certain percent of Narco product in a given period and retain your field repair privileges for the Narco line.

Dealers that didnt make sales quotas were stripped of their ability to purchase factory provided service parts. No new radio sales? Sorry, no parts. So many dealers, unable to make sales numbers, lost the Narco master dealer status and can no longer effectively support the Narco radios in service.

Narco factory repair is often the only option for repair. Thats reasonable but it gets worse. Until recently, the owner had to agree up front to pay up to the average repair cost of the box being serviced, about $500. Narco recently changed that to simply repairing at any cost. This doesnt sit we’ll with us or most owners. So, for this reason, we caution against Narco.

Most shops have a bitter attitude toward Narco because many have lost customers as a result of the companys policy. We acknowledge that Narco factory service is exceptional, turning out quality repairs on most boxes. Its just that customers feel trapped when repairs are necessary. At this state of play, we don’t recommend the Collins MicroLine VHF251 comm or VIR351 nav radios because of the concern for future serviceability. DME? But Why?

Pre-GPS IFR pilots still feel naked cruising around terminal areas without DME; we feel your pain. But get over it. If you have GPS, you can easily get by without DME.

However, if you have to have DME, make it a good one. The Bendix/King KN64/KN62/KN63 series, all digital current production models, are limited on the used market because of their recognized high quality. These units are reliable, take little panel space and will remotely channel with a wide variety of nav systems, including the Garmin GNS430.

The KN63 is high dollar because of its remote mounted box and small control head. Clearly, a great DME system if you just hafta have one. Units to stay away from at any cost? The Bendix/King KN65 series, Narco DME190 series and even the Collins DME450s.

Another way to get DME is through the Bendix/King KNS80 RNAV. A flooded market has driven the cost of this system to near rock bottom.

A one-time state-of-the-art box, the KNS80 is a full featured nav system with VOR/LOC/glideslope/DME and rho-theta RNAV. When properly interfaced, its a legal RNAV unit, although it consumes a lot of panel space.

The KNS81 is also an RNAV system, but one without an internal DME. When KNS80 standalone nav is removed, the standalone 720-channel KY196/197 series comm radios go along. The market is flooded with decent KY196 (28-volt) and KY197 (14-volt) comms. KY197A/KY196A are later model radios with memory storage capability and 760 channels.

Narco has a similar design in the NS800 and NS801 nav systems but manufactured far fewer units than Bendix/Kings KNS series and its apparent that the KNS80 is more field serviceable than either Narco.

The accompanying Narco standalone comm is the COM810 (14-volt) and COM811 (28- volt) transceiver. Decent radios, but again, the Narco service policy is a concern.

Collins manufactured RNAV computers, too, but none of those are worth installing at this point, in our view. In short, if you really need DME, hunt for a KN64 or better and a TSOd KN62A. Snag it quick; it will be sold by tomorrow.

Although some diehards appreciate the benefits of ADF, most owners are unwilling to make the investment to install even a used system, which the market is flooded with. In this case, Bendix/King wins with the digital KR87 ADF system. Still a production item, IFR GPS equipped aircraft are, nonetheless, shedding these systems.

The KR87 is a reliable ADF. The antenna, the KA44B is a combination sense/loop antenna that eliminates the clothesline style sense antenna strung across the top of the cabin. Beware of earlier systems that have the KA44 blade-style antenna; its too large for a small airplane.

All self-contained KR86 ADF systems by Bendix/King can be problematic with expensive cam gear problems and band switch difficulties. Avoid them. Narco made the ADF841 digital ADF, which is also a good system. Still, the Bendix/King digital KR87 is our top choice.

While a transponder failure often hits your wallet by surprise, you have no choice but to fix it or replace it before you do any serious flying. Our philosophy is to buy new whenever budget allows.

State-of-the-art transponders tend to be solid-state design and promise to last longer and require less maintenance than on older designs. We suggest avoiding Cessna/ARC RT359/RT459 units simply because of age. If you cant spend the money for new, the Bendix/King KT76A is as dated as we would recommend. The KT76, KT78, as we’ll as Narco AT50 and AT50A units are too long in the tooth to be economical. Our advice on transponders is if the box can be definitively fixed for $300 or less, consider it. Otherwise, look at a used KT76A. And make sure its actually a KT76A and not a KT76 with an A faceplate. Weve seen that before.

Although Garmin has become the industry buzz word with owners throwing GNS430s and 530s at their airplanes in record breaking numbers, later production Bendix/King Silver Crown radios were once the equipment to have and in the used market, this is still the case.

If we couldnt have GNS430s or UPS-AT suites, we would be confident installing KX155s, for example, as primary systems. The same is true for the Silver Crown DME, ADF and audio systems we mentioned. After all, what was industry standard and extremely capable just a few years back is still just as capable today, if you know what youre buying.

Some hints on how not to get hosed: Work with a shop that has removed the equipment and that has experience working with it. Traceability is a concern; make sure it has visible serial numbers. Be sure the equipment comes with installation hardware. A seemingly good deal at the outset could turn costly and ultimately evil as the install progresses.

Standard warranty on used equipment ranges from three to six months, with a full year being a bonus on certain late-model stuff. In short, if youre careful, you could do quite we’ll with certain used equipment. Its worth considering.

Also With This Article
Click here to view “Checklist.”
Click here to view “Slide-Ins? The Suns About to Set.”
Click here to view “Used Gear Retail Prices.”

-by Larry Anglisano

Larry Anglisano is an Aviation Consumer contributing editor. He works at Exxel Avionics, in Hartford, Connecticut.