Fix or replace my autopilot?

[aviatoreb]

Well, autopilot is buggy.  KFC200.   It oscillates in roll.  Its a KFC200 on a M20K.  Both HSI and attitude/director were overhauled about 150hrs ago and seem to be working well as far as I can tell.  A shop recently retensioned the cables as a first line attempt to fix the problem but it didn't work.  Now it looks like it will start to get expensive to find the problem.  Will it be a matter of replacing one part after another until it is fixed and will I eventually be buying a brand new KFC200 one part at a time?  I don't know and I have not been down this path so I would appreciate your advice and any stories of similar experiences.  I suppose next in line would be to replace/overhaul roll servos?  Or do they go after the AP computer next?

Or should I skip all that and not risk throwing good money after bad and start to think about a whole new AP?  As far as I can tell an STEC30 is functionally in terms of capability close to the KFC200 and so the least expensive on par new replacement.  I see it looks like ~$12500 from PennAvionics installed using my current attitude/hsi (is that allowed?).

Or does anyone know a AP shop in the east which can hunt down my problem relatively accurately. I don't really feel like I need an upgrade - I just want it to work.

[carqwik]

Find a very good A/P shop and have them test your computer (having ruled out other things like servos).  I had a problem with my KFC-150 many years ago in that it would not hold altitude and the VS control was completely whacky.  Problem got progressively worse over time.  Went through the route of checking a bunch of stuff...servos, bridle cable, AI, etc. Even had a so-called good autopilot shop on the West Coast look at it...no fix after many AMUs.  Decided to go to Autopilots Central in Tulsa..called them and described the problem.  Shop manager tentatively diagnosed the likely problem on the phone but wouldn't know til he looked at it...took 3 months to get a shop appointment.  They fixed the problem in half a day....cold solder on one of the board seats in the A/P computer.  Just wish I had gone there first (despite their being 5+ hour flight from my home base).

 

[Parker_Woodruff]

I would personally go for a Century 2000 after hearing the lackluster support reviews from Cobham.  That is, if you decide to replace.

Can you get any money from your KFC200 as it is?

[jlunseth]

Aviation Consumer did a review of AP's recently and the Kings were quite a bit better than the others.  The King's forte is ability to control flight in turbulence without decoupling.  I am keepin' my KFC200.  Works pretty good.

[David Mazer]

I had a terrible time with my KFC 150 when I got my plane in 2006.  The estimate to replace the unit was north of $20,000 if I wanted the same capabilities.  First I took it to one shop and they didn't really solve the problem even though they sent the unit back to Autopilot Central three times as one of the other posts described.  I finally left the plane with Sarasota Avionics (SA) for an extended period of time and thought I was going down the same dead end until, viola, it was fixed.  I opted not to bother with the yaw dampener which would have cost about $2,500 to repair since something got bent when it was left on on landing some time prior to my acquiring the plane.  Sarasota charged about $7,000 for the repair.  Very painful but still less than a new unit by far.

The people at SA believe their technician is especially gifted with autopilots.  Maybe,maybe not but mine is working well now.  Are you near FL?

[LFOD]

This is a timely post. My KAP 150 is DOA and I just shipped it out to Autopilots Central for repair. I will let you know how it works out. In fact, one of the first things that I checked when I bought my current plane was the operation of the autopilot. Gave me a good 18 months of service before it dumped on me. Oh well.

[jelswick]

My Century 21 went on the blink and worked great if you wanted to turn right, e.g. turning 270 degrees meant the long way around.  I replaced it with an STec 30 in January along with install of the Aspens and thrilled with it so far.  I'd had an STec 20 before in my C and was very pleased with that and just liking that much more now having the altitude hold.  I'd read that you can spend a fortune (cost of installing an STec) in troubleshooting and fixing parts as you go along through the diagnosis of the old A/P's issues, so I decided to forego that risking only finding out it was time to replace my '81 era autopilot.  Pricey, but glad to have the new equipment with better capability onboard now. 

[aviatoreb]

Quote: LFOD

This is a timely post. My KAP 150 is DOA and I just shipped it out to Autopilots Central for repair. I will let you know how it works out. In fact, one of the first things that I checked when I bought my current plane was the operation of the autopilot. Gave me a good 18 months of service before it dumped on me. Oh well.

[Piloto]

Autopilots are expensive items to replace with a different model. Typically you are better off having it fix. Your roll problem may be something as simple as a worn out servo clutch. Try the following: on the ground set the heading bug to current heading. Engage the AP. Try to override the AP by hand on the yoke. You should feel considerable resistance on attemping to rotate the yoke. If minimum resistance is felt is an indication of a servo worn out clutch. A worn out clutch can be compensated by tightening the clutch friction adjustment or by replacing it. The clutch looks like a washer coated with a sandy material.

Jose

  

[LFOD]

Will do... I really hope your problems are on the low side of their estimate. 5K to fix a 20 year old autopilot is quite a gamble. 

[David Mazer]

I just briefly reviewed the differences in capabilities between a KFC 200 and an Stec 30.  I can't believe you would be happy replacing a KFC 200 with an Stec 30.  The difference in capabilities is huge.  Even if you have to pay the same amount to repair the KFC 200 as a new Stec 30, you would be way ahead.

[aviatoreb]

Quote: LFOD

Will do... I really hope your problems are on the low side of their estimate. 5K to fix a 20 year old autopilot is quite a gamble. 

[LFOD]

So far, only $250 for removal, testing and shipping to Autopilot Central. I do agree with Mazerbase, that an STEC 30 would be a major step down from a 200.  Just chasing after problems with APs can get difficult, not to mention expensive. 

[Jerry 5TJ]

My 1983 IBM PC with 64K and dual floppy drives cost me $3000 new back then, and now the darn techs tell me it will cost that much to repair it! Where do they get off!?!  They say it would be cheaper to buy something new...come on guys, the stuff in our Mooney panels is OLD, it can cost major money to fix and yet more to replace. 

Flew my 65C today from LA to SF in 3.1 hours and the Brittain wing leveler worked great now that I've rebuilt the yoke cut-out switch.  Still, a $12K S-Tec 30 would be far, far better.  Etc.

 

 

[LFOD]

Quote: jerry-N5911Q

My 1983 IBM PC with 64K and dual floppy drives cost me $3000 new back then, and now the darn techs tell me it will cost that much to repair it! Where do they get off!?!  They say it would be cheaper to buy something new...come on guys, the stuff in our Mooney panels is OLD, it can cost major money to fix and yet more to replace. 

Flew my 65C today from LA to SF in 3.1 hours and the Brittain wing leveler worked great now that I've rebuilt the yoke cut-out switch.  Still, a $12K S-Tec 30 would be far, far better.  Etc.

 

 

[jelswick]

I think it might come down to what your replacing too.  My J already had electric trim, so it wasn't a consideration in the AP replacement.  The STec30 is definitely more capable than the basic Century 21 AP that was in my aircraft, so not a comparison to function of someone with something like a KFC 200.  Penn Avionics and a few others I researched had a great article on the risks in repair of old autopilots.  If something is old enough that it is failing in the system and you start down the line troubleshooting all of those items in an AP system, even if not yet failed, many of those parts may be found to be aged/worn out enough to require replacement during the troubleshooting process and that can possibly quickly get to the price of a new STec.  For a KFC 200 or similar, that logic might not hold, but for an Century 21 or similar, I wouldn't have to replace too many parts before I'd wish I'd splurged for the new AP.  There just wasn't that much capability to try to hold onto to start with.

Where did they come up with these AP names anyway?  Century 21 has me thinking real estate and KFC 200 is making fried chicken sound like good breakfast food today... 

[PTK]

Find a very good autolilot shop and fix it.  You have an excellent and solid ap.  Don't even think of Century or Stec.  I'm not an expert but I have done a lot of research to educate myself because I have the KFC 150.  King ap's are the most sought after when people look to buy Mooneys and I'm sure other planes.   There is an ap shop out west in CA I came acoss and called.  I don't recall the name but the number is (918)836-6418.  The gentleman's name is Bob.  He is very busy but once he was able to get on the phone he stayed on the phone with me for about 45 minutes explaining in detail my ap intricancies.  He gave me an education on exactly how it works and was to look for.  He was very happy to answer my questions.  Maybe it would be worth your while to just call him and get an opinion over the phone.  If it is the computer you can ship it.  If they need the whole airplane then maybe its not practicaL for you.

[Awful_Charlie]

Whilst we're talking autopilots, although I can't offer much for the above, anyone know how the KAS297 integrates to the KFC150?  I have to select an altitude 200' below the desired one to be close, and although it's not a major problem, if it is simple to dial out I'd like to get it done.

[aviatoreb]

Quote: jerry-N5911Q

My 1983 IBM PC with 64K and dual floppy drives cost me $3000 new back then, and now the darn techs tell me it will cost that much to repair it! Where do they get off!?!  They say it would be cheaper to buy something new...come on guys, the stuff in our Mooney panels is OLD, it can cost major money to fix and yet more to replace. 

Flew my 65C today from LA to SF in 3.1 hours and the Brittain wing leveler worked great now that I've rebuilt the yoke cut-out switch.  Still, a $12K S-Tec 30 would be far, far better.  Etc.

 

 

[aviatoreb]

Quote: LFOD

I dont think your analogy holds up.  Altitude hold is altitude hold; same goes for heading. At least with my 20 year olld AP I can control VS and ride the glideslope. Oh, and it also has auto trim (an expensive option with the Stec).  These options are not on the Stec 30. It would be an expensive step back to at least not give a repair a try. 

[aviatoreb]

Quote: jelswick

Where did they come up with these AP names anyway?  Century 21 has me thinking real estate and KFC 200 is making fried chicken sound like good breakfast food today... 

[PTK]

Quote: jerry-N5911Q

My 1983 IBM PC with 64K and dual floppy drives cost me $3000 new back then, and now the darn techs tell me it will cost that much to repair it! Where do they get off!?!  They say it would be cheaper to buy something new...come on guys, the stuff in our Mooney panels is OLD, it can cost major money to fix and yet more to replace. 

Flew my 65C today from LA to SF in 3.1 hours and the Brittain wing leveler worked great now that I've rebuilt the yoke cut-out switch.  Still, a $12K S-Tec 30 would be far, far better.  Etc.

 

 

[Cruiser]

Quote: aviatoreb

[jlunseth]

Quote: Awful_Charlie

Whilst we're talking autopilots, although I can't offer much for the above, anyone know how the KAS297 integrates to the KFC150?

[PTK]

Quote: aviatoreb

Well, autopilot is buggy.  KFC200.   It oscillates in roll.  Its a KFC200 on a M20K.  Both HSI and attitude/director were overhauled about 150hrs ago and seem to be working well as far as I can tell.  A shop recently retensioned the cables as a first line attempt to fix the problem but it didn't work.  Now it looks like it will start to get expensive to find the problem.  Will it be a matter of replacing one part after another until it is fixed and will I eventually be buying a brand new KFC200 one part at a time?  I don't know and I have not been down this path so I would appreciate your advice and any stories of similar experiences.  I suppose next in line would be to replace/overhaul roll servos?  Or do they go after the AP computer next?

Or should I skip all that and not risk throwing good money after bad and start to think about a whole new AP?  As far as I can tell an STEC30 is functionally in terms of capability close to the KFC200 and so the least expensive on par new replacement.  I see it looks like ~$12500 from PennAvionics installed using my current attitude/hsi (is that allowed?).

Or does anyone know a AP shop in the east which can hunt down my problem relatively accurately. I don't really feel like I need an upgrade - I just want it to work.