This should be a good debate -- GPS's


I have just bought a 1999 C182S with 5 partners. The plane is equipped with a King KLN89B (IFR Certified). Our group has a wide range of experience but 2 of us are Instrument Rated. We are debating the future of the 89B and I believe that the options can be boiled down to:

Keep the 89B, the IFR pilots will learn how to use it safely.

Replace the 89B with a 94. This is a pretty inexpensive option but some of our advisors are quite negative on the KLN94.

Replace the 89B with a Garmin 430. This is a more expensive option; some of our advisors say that is equipping the plane with the best mixture of capability and economy … others ask why you would change the GPS when the upgrade to the 94 is a pin compatible inline upgrade.

Replace the 89B with a 94 and buy a King Multi Function Display. Comparable in price to the Garmin 430, probably a better display than you get with the Garmin but again raises the question about which unit is actually better to use as an IFR navigation platform and subjectively by how much.

I’m hoping to hear from a cross section of pilots who can comment on this, I’ll bet that there is a lot of partisanship in our community about this so it should be fascinating to read your responses.

Thanks in advance,



Ive used every one of the GPS’s you described. Each has its own plusses and minuses. Many people are surprised to hear that the Pilatus-es (Pilatii?) I fly have a simple KLN90 GPS. Very plain, but it works. Ive used the 89B and the 94, the 94 is better since you can load ILS and LOC approaches in it, the 89B doesnt. Plus its color.
The 430 is a very good choice, cannot complain about it at all. Nice feature is being able to show holds.
MFD’s are always nice, if you have the room for it, why not?



Keep the 86B and get a Garmin 396 with XM WX. You can still file /G but can navigate with the 396. Beautiful color screen and very easy to use. Plus it also gets XM music so you have in-flight tunes. They even make a panel mount for it. Plus you’ll save yourself a couple grand.


Only problem with that is not being able to sync the autopilot to the 396. I’m assuming it has an autopilot, I couldnt imagine a 99 sklane not having one.


True, but entering a flight plan into any of the mentioned GPS units is all very similiar. It isn’t difficult to enter an identical plan into the 89B and 396 and monitor both. Still a valid point and an extra step added to your workload, but i’ve done it and its very simple.

Plus with the 396 you can check weather, and review your flight plan before you even get to the plane. This is especially convinient at airports without an FBO or if the FBO is closed.

You can also recieve TIS with the Garmin GTX330.


The plane does have a kap400 autopilot.

The 396 idea has been floated and looks like a good compromise but we are getting a lot of advice regarding the shortcomings of the 89B particularly approaches and more particularly missed approach sequencing. I have never flown a GPS approach myself although I have kept my instrument rating current since 1989 (in Canada, this requires flying a flight test with an examiner every second year, but I do it every year because Canadian regulations consider you current for one year after flying an IFR flight test). What I am struggling with is the question of whether the Garmin 430 is a superior product to the King KLN94. If they are effectively equivalent, it seems to me to be better to spend on the upgrade to the KLN94 plus an MFD than to buy Garmin.

Thanks again for your responses.


The GNS 430 does have several advantages over the KLN94. One of the largest differences is the 430 has a built in NAV/COM. Not only does this eliminate equipment from the panel, but it makes if much easier to enter frequencies. The 430 also has a 12 channel GPS reciever vs. the 94’s 8 channel. The 430 has a larger easier to read screen and in my opinion is a bit more user friendly than the 94. As with most IFR GPS’s neither unit will automatically sequence after the missed approach point. That must be initated by the pilot. But re-activating the same approach with the 430 requires only 2 button presses.

As far as flying approaches, both are similar. The 94 is much improved over the 89B as it has a Procedure button and automatically sequences from leg mode to OBS, as does the 430. With the 89B, if you don’t change to obs mode, the approach won’t go active, you have to manually re-enter the procedure and likely do the entire approach again.

I suppose, in your situation, i would recommend the KLN 94 since there is virtually no installation cost and if you have a Bendix/King radio stack, I think you can sync the GPS to automatically enter frequencies. I’d still skip the MFD and get the Garmin 396.

You can download a GNS 430 simulator from Garmin if you’d like to mess around with it. There is no simulator available for the KLN 94.


Stick with what you already have - it is much cheaper and easier. Those upgrades will not allow you to shoot approaches to any lower minima, or get anywhere that you can’t go now. The question was once asked - “Which GPS is the easiest to use?” and the wise answer was “The one that is in your airplane - you learn how to use it.”


Easier is relative… its only easier if you are well trained in that particular piece of equipment. If you’ve never used a GPS they would all be equally “easy”. Although its said that the 430 is well suited to the “Direct-To” VFR pilots because of its ease.

Actually the GNS 430 is capable of the WAAS upgrade, operating under a new TSO, allowing precision LPV approaches to minimums as low as 250 feet without the need of a VOR. So technically the upgrades could allow you to go places that the current equipment couldn’t go.

Here’s a good link comparing some popular panel mount GPS. Which GPS is Right for You?


What will ultimately drive the choice, money or utility. If economy rules, the 396 is a workable option and the weather is nice. If the operator is current and competent then instrument operations can certainly be done.
The 430 is simply still the best thing on the market for utility and user friendliness. It makes approaches as simple as a GPS can do this. An MFD should only be considered after the GPS choice is made.


Could you explain why you say the GPSMAP 396 cannot accept the moving map output (via rs-232) from the KLN 89B? … jsp?id=921

This update will also upgrade the software in your GXM30 antenna to version 2.20.
XM Audio Favorites may be deleted when applying this update.
Change History

Changes made from version 3.10 to 3.20:

Improved reception of weather data.
Improved terrain alerting when navigating a route using the Aviation In serial data protocol.
Added density altitude to METAR text.
Changes made from version 3.00 to 3.10:

Improved display of timestamp for winds and pressure data.
Improved aviation route transfers to and from Mapsource.
Improved display of lake depth contours in Marine mode.
Improved TracBack when using the entire track.
Improved GPS reception.
Changes made from version 2.80 to 3.00:

Added Iceland time zone
Added support for latest Garmin map technology
Added separate options on map setup page for private airports and heliports
Added option for county warning weather alarms to persist
Added ability to quickly select entire track for use with TracBack
Added ability to use altimeter setting from nearest METAR reporting station with E6B calculator
Modified XM Audio page to retain previous category selection when unit is powered off
Modified Aviation In serial data format to work with avionics that do not output linefeed characters
Modified AIRMETs and SIGMETs to appear when zoomed out to at or above the selected range instead of below
Improved calculation of ETE on active route page
Improved appearance of Class D and Alert Area airspace types
Improved appearance of map in aviation mode when terrain shading is turned off
Improved voice guidance for road routes
Improved appearance of automotive mode maps
Improved display of private airports
Improved frequency display on Airport review page for airports that have only one comm frequency
Improved selection of airports that are displayed on the Nearest Wx page
Improved Compass page in Automotive mode
Improved Sonar page
Improved Find menu
Improved map selection when changing usage modes
Corrected number of decimal places shown for Altimeter field when using map page ‘Map With Overlay’ page layout
Corrected issue that could prevent some message log filter settings from being saved
Corrected issue that could cause unit to shut down when using the Highway page
Corrected issue with waypoint timestamp updates when transferring from Mapsource
Corrected display of ‘L’ symbol in Turn data field
Corrected display of ‘Route Truncated’ and similar messages when using USB
Corrected problem with receiving weather data when the unit is left on for long periods of time
Corrected problem with receiving weather data when Battery Saver mode is used
Corrected display of surface wind indicators when the map is in Track Up orientation
Corrected display of radar coverage data
Corrected rare unit lockup when operating with poor XM reception
Corrected problems with Aviation In serial data format
Corrected incorrect display of ‘No Subscription’ for XM service level
Corrected display of cardinal direction on map page when measuring distance
Corrected duplicate waypoint creation with GPWPL NMEA sentence input
Corrected hilight movement problem on proximity waypoint page
Corrected invalid display of Next Turn data field
Corrected lockup that could occur after updating terrain or obstacle databases
Updated text translations

paul sanchez


How can the KLN94 load the NAV/COM frequencies to the KX155a if the harness is not changed from the KLN 89B harness? It certainly is not “$0” installation cost if you want all the features of the KLN 94.

paul sanchez


I didnt.


I said virtually no cost. Plus that was before i mentioned linking the 94 to the radio stack. Still cheaper than buying a 430.


Good morning magnetoz:
Agreed that the KLN 94 being inserted in the KLN 89B tray will have the same features as the KLN 89B. As long as the owner/operator realizes that all the other new features of the KLN 94 such as frequency loading, roll-steering, altitude serializer input, etc are not automatically included and certainly not for “free”.

Installation of avionics is where a good portion of the budget is eaten up. A Garmin GNS430 has less installation costs than a KLN 94 and KX 155a, including one reason that you do not need an annunciator/switcher installed for the GNS430.

It will always come down to the choice/budget of the owner/operator, and if they are full aware ahead of time of what features/capability they will get (versus what they presume they’ll get) then they’ll be quite satisified.

My experience has shown a majority of owner/operators were well over-promised on what their equipment will do.


There are many new features on the KLN94 that are free.
-A color screen
-A new Procedure button, significantly improving the ease of loading approach procedures
-Vector-to-Final feature, eliminate having to put the unit into OBS mode to get established on final approach
-Overlay approaches
-Many other software upgrades to make the 94 much more friendly to use than the 89.

You made it sound like replacing the 89B with the 94 would only have the same features.

Granted, you might not be able to utilize every new feature of the 94 with a simple unit swap, but its still an upgrade and has its advantages. And it is up to the owner to get as much information about the system before the purchase if they want to be satisfied by its performance.



That I always agree with.


Sanchez, you sound like you know your shit. Are you an avionics dealer/installer? If so I guess you could be the resident avionics expert! (of course we’d have to have a look at your resume, and you must know the position is very poorly paying.)


Certainly not an avionics dealer/installer. Just know a moderate amount of the software and do qualification courses on the equipment and the aircraft.

If you are in town on 13 August to 18 august I’ll be in MHT. PC12 client 13-16 August and then the PC12 regional conference from the evening of 16 August and then all day on 17 August.