Mooney M20J LM with KFC 100 wants altitude hold

[Lawmansteve]

Hello everyone,

We have a 201j LM the lm designation tells people that it is lean - specifically meaning there is only a single axis autopilot and trim is manual.  We are looking to add altitude hold at a reasonable price and we have a great panel two GI275 and the GTN750 vacuume deleted.  I would like suggestions, I’ve been flying cross country and being able to hold altitude would be great!  Is there an upgrade to the KFC150 that can be done by installing a used one and adding the electric trim?

thanks

[LANCECASPER]

11 hours ago, Lawmansteve said:

Hello everyone,

We have a 201j LM the lm designation tells people that it is lean - specifically meaning there is only a single axis autopilot and trim is manual.  We are looking to add altitude hold at a reasonable price and we have a great panel two GI275 and the GTN750 vacuume deleted.  I would like suggestions, I’ve been flying cross country and being able to hold altitude would be great!  Is there an upgrade to the KFC150 that can be done by installing a used one and adding the electric trim?

thanks

You probably have a KAP100, which if I remember correctly is what the Lean Machine came with. I've never heard of a KFC100. (KFC=King Flight Control System; KAP=King Autopilot. The KFC has the Flight Director.)

 

 

You've probably seen this before, but it explains the differences between the KFC150, KAP150 and KAP100:  https://www.bendixking.com/content/dam/bendixking/en/documents/downloads/006-08377-0001_1-kap-150-ki-525a-pilot-s-guide.pdf

The roll and pitch servos in the KAP100 are the same roll and pitch servos in the KAP150 and KFC150 so that's a start. If it's possible to move to the KAP150 that would be easier since your attitude indicator should work with it. You'd need a Pitch trim servo and a KC191 computer to replace your KC190 and probably a lot of wiring for approaches etc. Not even sure exactly how you'd make it a legal installation, paperwork-wise.

It might be less expensive to start over with something more modern, like the Aerocruze 100. The man who would know whether your autopilot could be built into a KAP150 or KFC 150 is @Jake@BevanAviation

[Jake@BevanAviation]

@Lawmansteve The KAP100 was a roll axis only autopilot, the KAP150 was roll, pitch, and pitch trim. The KFC150 added flight director functions with roll, pitch, and pitch trim standard, with a option for yaw.  Finding a good used KAP150 should not be that big of a problem, the challenge is the servos, brackets, hardware, ect.  Not to mention the install cost and paperwork to make it all legal.  

If you are wanting a modern 2-3 axis autopilot system it might be smart to look at new systems.  The Aerocruze will be the lowest cost but has some limitations. S-Tec and Garmin will be a step up from the Aerocruze.  With the equipment you already have in the aircraft you can't go wrong with the GFC500.  It will cost you more vs the Aerocruze but you will have a lot more features with Garmin.