I'm looking at a Mooney M20C with a pretty dated panel, but it's airworthy and could be a great opportunity to build some retrac time. The KLN89b GPS is IFR Certified, but is positively ancient.

There seems to be a convoluted process to keep it up to date. I don't know if the present owner has the cable or the proprietary card reader. I've found some on eBay that seem to be for the KLN94 so I'm not sure if they will work with the KLN89b.

In my club we have a C172 with a GNS430 that has a fairly straightforward update process. I'm hoping the KLN89b is pretty similar if I get the card reader. I certainly don't want to take the entire GPS out of the aircraft and load it into a docking station every month.

If anyone can share their experience with this unit that would be great.

  • $\begingroup$ I might suggest checking the manufacturer's web-site to see if A) They have the hardware available that you need to do the updates, and B) they're still providing updates for it. (I'm not sure how old the KLN89b is, so that may not be that applicable.) $\endgroup$
    – FreeMan
    Feb 29, 2016 at 16:41
  • $\begingroup$ They do provide the updates, but explain very little about how to apply them. I've seen some Youtube videos that show the DB being updated by pulling the entire GPS out of the aircraft, installing it in a purpose build "docking station" that costs a few hundred bucks and then running some software on an XP-era PC. If that's the only way then I'm probably going to opt out. $\endgroup$
    – John Hoge
    Feb 29, 2016 at 17:14
  • $\begingroup$ @JohnHoge, well, you could try asking around maintenance shops whether they can upgrade it for you. $\endgroup$
    – Jan Hudec
    Feb 29, 2016 at 18:38
  • $\begingroup$ I'd like to upgrade to a GTN650 ... but I checked the price and now understand that IFR stands for "Infinite Funds Required" .. wondering if I can get by on the this old Apple-II vintage GPS for a few years while I save up! $\endgroup$
    – John Hoge
    Feb 29, 2016 at 18:47
  • $\begingroup$ The manuals posted [here][1] have a description for the data cable[1]:lonestaraviation.com/Commander-2000K-GPS-Docking-Stations.html $\endgroup$
    – cavver
    Feb 29, 2016 at 21:24

2 Answers 2


Thanks Guys. I've contacted the manufacturer and they said that there is an approved cable, only sold by avionics shops, that will connect an old fashioned serial port to the data port on the panel. If I get a USB to serial computer, I may be able to use Windows 10 to install the update. Maybe I'll have to downgrade to Win7.

I asked if there was a published end-of-service date for the unit and they stated that there was not. I also asked if there was a guarantee of future database availability for any period into the future and she said that there was no guarantee, but no plans that she knew of to phase the unit out.


a) windows or dos computer with a serial port is required to run the official software b) almost every USB (or Bluetooth) to serial adapter works without any trouble if there are supported (if you have a proper driver for the operating system) c) only TX, RX and GND are connected to KLN89 or KLN94 device

e) solution for mac or ios device exists ... unofficially :-) (send me a message if you are interesting)


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