ASPEN/KFC 200 Issues

[Flynnupe94]

I recently updated my panel with an 2 tube Aspen Evolution to go along with a King KFC 200 autopilot. I also installed a EA100 autopilot interface. Before updating my panel I did not have any issues with my autopilot at all. It was rock solid, held altitude well. However, now im having slight pitch occillations which feels like someone is bumping the controls. I have been to two avionics shops or of which consulted with the Aspen rep in the area however to problem still exist. The problem isnt continuous and comes and goes during the flight. Does anyone have any ideas? Im about to pull my hair out.. 

[bnicolette]

Have you spoken with Autopilots Central in Tulsa, OK?

[Marauder]

I recently updated my panel with an 2 tube Aspen Evolution to go along with a King KFC 200 autopilot. I also installed a EA100 autopilot interface. Before updating my panel I did not have any issues with my autopilot at all. It was rock solid, held altitude well. However, now im having slight pitch occillations which feels like someone is bumping the controls. I have been to two avionics shops or of which consulted with the Aspen rep in the area however to problem still exist. The problem isnt continuous and comes and goes during the flight. Does anyone have any ideas? Im about to pull my hair out..

I have the dual Aspen setup with an STEC 60-2. On a very calm air flight I can feel a little oscillation but it is definitely not in the "bump the controls" category. If I am not mistaken, the EA 100 replaces the attitude indicator used for the analog signal for your AP. In your case, I suspect it is a calibration issue between the EA 100 (which I don't need) and the KFC 200. I would call Aspen directly and speak to their technical support. They are very customer oriented and will discuss it with you.

[David Mazer]

I replaced my AI with the EA 100 when my AI failed for a second time and each rebuild was $2,500.  I thought the EA 100 would be a reasonable replacement even though it cost $5,000 installed.  It has proven to be, as you note, not very smooth.  I regularly see a 100 ft variation in altitude for every course correction (after passing a fix, for example, or during a procedure turn.  The people that installed it, Sarasota Avionics, claim that is within design standards.  I wish my old AI had been more reliable.  If you find a good answer, please let me know.

 

Oh, I have a KFC-150.

[Flynnupe]

Have you spoken with Autopilots Central in Tulsa, OK?

No I havent but I will tomorrow...

[Flynnupe]

I replaced my AI with the EA 100 when my AI failed for a second time and each rebuild was $2,500.  I thought the EA 100 would be a reasonable replacement even though it cost $5,000 installed.  It has proven to be, as you note, not very smooth.  I regularly see a 100 ft variation in altitude for every course correction (after passing a fix, for example, or during a procedure turn.  The people that installed it, Sarasota Avionics, claim that is within design standards.  I wish my old AI had been more reliable.  If you find a good answer, please let me know.

 

Oh, I have a KFC-150.

Ill let you know what I find out. This has been frustrating to say the least...

[Flynnupe]

I have the dual Aspen setup with an STEC 60-2. On a very calm air flight I can feel a little oscillation but it is definitely not in the "bump the controls" category. If I am not mistaken, the EA 100 replaces the attitude indicator used for the analog signal for your AP. In your case, I suspect it is a calibration issue between the EA 100 (which I don't need) and the KFC 200. I would call Aspen directly and speak to their technical support. They are very customer oriented and will discuss it with you.

Its definitely noticable, but funny thing is it will stop after a while then start again. The avionics shop that did the install had the Aspen rep make adjustments but on my trip to Orlando, it still was there...

[Marauder]

I have the dual Aspen setup with an STEC 60-2. On a very calm air flight I can feel a little oscillation but it is definitely not in the "bump the controls" category. If I am not mistaken, the EA 100 replaces the attitude indicator used for the analog signal for your AP. In your case, I suspect it is a calibration issue between the EA 100 (which I don't need) and the KFC 200. I would call Aspen directly and speak to their technical support. They are very customer oriented and will discuss it with you. Its definitely noticable, but funny thing is it will stop after a while then start again. The avionics shop that did the install had the Aspen rep make adjustments but on my trip to Orlando, it still was there...

Things that come and go when dealing with electronic devices typically are related to some component that is failing for some reason (I.e. heating up, vibration, premature failure, etc,). Let us know what you find out.

[peter]

Its definitely noticable, but funny thing is it will stop after a while then start again. The avionics shop that did the install had the Aspen rep make adjustments but on my trip to Orlando, it still was there...

Obviously your original problem remains unresolved.  I recommend you follow back up with the shop/Aspen to continue to troubleshoot what they apparently believed to be a setup/adjustment issue. 

[Flynnupe94]

Obviously your original problem remains unresolved.  I recommend you follow back up with the shop/Aspen to continue to troubleshoot what they apparently believed to be a setup/adjustment issue. 

I called the avionics shop this morning in order to get this resolved. I was hoping that someone else had this problem so that I can get this problem taken care of faster...

[gjkirsch]

As others have said, calibration would be my first guess, but since they moved a bunch of stuff around during the install, could there now be a leak in the static system?

[Bennett]

I hate "tinkering" with autopilots, and the avionics that drive them. I have a MidContinent AI, a GTN 750, (and GTN 650), and an Icarus SAM GPSS steering unit for digital to analog conversion for my KAP 150 autopilot. All was perfect for about two years with this setup, until the nose started bobbing up and down when in altitude hold. The aircraft didn't really gain or lose altitude, just started bobbing at a rate of about 30 bobs per minute. Dang! I brought the airplane to LAC Avionics in San Jose, who had in years past repaired my KFC 200 autopilot. The good folks at LAC found that the AI was starting to fail, running slower than design, and actually you could hear grinding noises. I thought about replacing the AI with an Evolution one tube unit, but I really dislike speed and altitude tapes. I posted my feelings about this before on this forum, and I was happy with everything as it was before the AI created the problem. LAC installed a rebuilt MidContinent AI, and re-calibrated the output to meet the required voltages. Unfortunately this AI failed about two hours later - even the best rebuilder can produce a dud, and they immediately replaced that unit with a new one, which LAC then installed and calibrated. I test flew the airplane, and the nose still kept bobbing. Damn! So back to LAC, who now pulled out the pitch servo, and the KAP150. I said send them both back to Honeywell (the current owner/ servicer for Bendix / KIng) and have them checked, and if necessary, rebuilt. Honeywell sent the pitch servo back, saying they couldn't read the serial number, although they acknowledged that it was a BK pitch servo. Dan at LASAR helped me obtain the serial number from Mooney (amazing how the factory keeps all the records), and I sent them a .pdf of the Mooney factory records showing that serial number. Now it gets weird: Honeywell said the KAP150 (installed at the factory in 1983 as original equipment, and never worked on until Honeywell received it), was incorrectly programmed. They said the autopilot was set up for a Lake Amphibian. Highly unlikely, I thought, but they said they reprogrammed the unit to M20J specifications. They also said that the pitch servo needed to be rebuilt. This is starting to get expensive, but there really was no choice but to authorize the work. In time, the KAP150 was sent back to LAC, and installed, and later the pitch servo arrived. LAC applied a voltage to the unit, and the arm moved. A voltage of opposite polarity moved the arm in the opposite direction. I then test flew the airplane again, and had one of the wildest rides in my flying life. Honeywell had mis -wired the pitch servo by crossing two wires, and the output was reversed polarity. When in flight, I turned on the autopilot, put it into altitude hold, and the next small gust resulted in a correction in the wrong direction - you can see where this is going. I tried to use the electric trim on the KAP150 to make a correction, and the unit went divergent on me, with huge excursions in altitude. I tried to shut off the autopilot with the switch on the KAP150 unit to no avail, then the red disconnect button on the yoke - no better luck, as by this time the pitch servo commanded full down, and apparently jammed. I tried CWS on the yoke - no change, and then the yoke electric trim switch which normally disconnects the autopilot - still heading down, and the houses were getting bigger, so I pulled the breaker, and that solved the immediate problem. The pitch servo went back to Honeywell, who in embarrassment, sent out a brand new pitch servo. LAC Avionics put it all back together, and all is fine now. The message here, if there is one, is that, in my experience, every time components are changed in the autopilot system, the precarious balance between the components results in a chain of failures. Getting everything back to where it was has taken months, and thank goodness for LAC who wouldn't give up in their battles with Honeywell on my behalf. Good people, and although the process was expensive, I'm sure they made no profit given the time they spent on the project.

[Marauder]

Bennett -- sounds like you were a true test pilot on that flight!

[Piloto]

I have seen this problem before. Before spending any money try this;

 

Pull the yoke all the way back and spray silicon lubricant on the yoke shaft. Move the yoke back and forth a couple of times.

Fly the plane to check it out.

 

The problem is related to minor binding of the shaft with the panel guide while in flight.

 

José 

[Marauder]

I have seen this problem before. Before spending any money try this; Pull the yoke all the way back and spray silicon lubricant on the yoke shaft. Move the yoke back and forth a couple of times. Fly the plane to check it out. The problem is related to minor binding of the shaft with the panel guide while in flight. José

Great idea! I hope this resolves his issue. I forgot all about these sticking. Mine do stick periodically and I do use silicone on them. i noticed this on my last pre-flight and forgot all about putting silicone on them! Thanks for the reminder.

[Bennett]

I had tried this before I found out the AI was truly failing. Good idea, though to check out potential binding. I've previously suggested marking the autopilot breaker with red nail polish, or a red cap so you don't have to hunt for it in a high stress situation.

[Flynnupe]

I hate "tinkering" with autopilots, and the avionics that drive them. I have a MidContinent AI, a GTN 750, (and GTN 650), and an Icarus SAM GPSS steering unit for digital to analog conversion for my KAP 150 autopilot. All was perfect for about two years with this setup, until the nose started bobbing up and down when in altitude hold. The aircraft didn't really gain or lose altitude, just started bobbing at a rate of about 30 bobs per minute. Dang! I brought the airplane to LAC Avionics in San Jose, who had in years past repaired my KFC 200 autopilot. The good folks at LAC found that the AI was starting to fail, running slower than design, and actually you could hear grinding noises. I thought about replacing the AI with an Evolution one tube unit, but I really dislike speed and altitude tapes. I posted my feelings about this before on this forum, and I was happy with everything as it was before the AI created the problem. LAC installed a rebuilt MidContinent AI, and re-calibrated the output to meet the required voltages. Unfortunately this AI failed about two hours later - even the best rebuilder can produce a dud, and they immediately replaced that unit with a new one, which LAC then installed and calibrated. I test flew the airplane, and the nose still kept bobbing. Damn! So back to LAC, who now pulled out the pitch servo, and the KAP150. I said send them both back to Honeywell (the current owner/ servicer for Bendix / KIng) and have them checked, and if necessary, rebuilt. Honeywell sent the pitch servo back, saying they couldn't read the serial number, although they acknowledged that it was a BK pitch servo. Dan at LASAR helped me obtain the serial number from Mooney (amazing how the factory keeps all the records), and I sent them a .pdf of the Mooney factory records showing that serial number. Now it gets weird: Honeywell said the KAP150 (installed at the factory in 1983 as original equipment, and never worked on until Honeywell received it), was incorrectly programmed. They said the autopilot was set up for a Lake Amphibian. Highly unlikely, I thought, but they said they reprogrammed the unit to M20J specifications. They also said that the pitch servo needed to be rebuilt. This is starting to get expensive, but there really was no choice but to authorize the work. In time, the KAP150 was sent back to LAC, and installed, and later the pitch servo arrived. LAC applied a voltage to the unit, and the arm moved. A voltage of opposite polarity moved the arm in the opposite direction. I then test flew the airplane again, and had one of the wildest rides in my flying life. Honeywell had mis -wired the pitch servo by crossing two wires, and the output was reversed polarity. When in flight, I turned on the autopilot, put it into altitude hold, and the next small gust resulted in a correction in the wrong direction - you can see where this is going. I tried to use the electric trim on the KAP150 to make a correction, and the unit went divergent on me, with huge excursions in altitude. I tried to shut off the autopilot with the switch on the KAP150 unit to no avail, then the red disconnect button on the yoke - no better luck, as by this time the pitch servo commanded full down, and apparently jammed. I tried CWS on the yoke - no change, and then the yoke electric trim switch which normally disconnects the autopilot - still heading down, and the houses were getting bigger, so I pulled the breaker, and that solved the immediate problem. The pitch servo went back to Honeywell, who in embarrassment, sent out a brand new pitch servo. LAC Avionics put it all back together, and all is fine now. The message here, if there is one, is that, in my experience, every time components are changed in the autopilot system, the precarious balance between the components results in a chain of failures. Getting everything back to where it was has taken months, and thank goodness for LAC who wouldn't give up in their battles with Honeywell on my behalf. Good people, and although the process was expensive, I'm sure they made no profit given the time they spent on the project.

wow my issues seem pale in comparrison to your issues. Im to the point of putting my old stuff back in.

[Flynnupe]

I have seen this problem before. Before spending any money try this;

 

Pull the yoke all the way back and spray silicon lubricant on the yoke shaft. Move the yoke back and forth a couple of times.

Fly the plane to check it out.

 

The problem is related to minor binding of the shaft with the panel guide while in flight.

 

José 

Jose thanks for the info I will definately try this, hopefully this will work...

[Flynnupe]

wow my issues seem pale in comparrison to your issues. Im to the point of putting my old stuff back in.

The only difference between our situations is that I have a 2 tube Aspen system. The only AI that I have is for backup. Also, throughout my flights using altitude hold, it will bob for awhile then stop. The flight is then smooth for awhile then start again...I have been to the Avionics shop at least three times, looks like they will have to put a bed in their office because Ive spent too much money on this project already. I never had any problems before with my autopilot...

[Marauder]

I don't know the feasibility of this, but can the original AI be re-installed and connected back to the AP to try to determine whether the Aspens are the root of the problem or that your AP developed a problem? It would make sense that a problem after a new installation was related to the installation and is most likely the culprit. But it could be that your AP has developed a problem that just happened to coincide with the Aspen install.

 

When my AP was installed, I only had a wing leveler. When the altitude hold and autotrim were added, I was popping a breaker on the AP. It turned out that my manual trim system was in need of a good cleaning and re-greasing. There was just too much resistance for the AP to deal with.

 

At some point the problem needs to be divided. Either putting in another EA100 or reverting to the former hardware configuration (AI for AP input) to see if the problem can be isolated.

[mbmaksymdc10]

Hi will send you my thoughts in a bit

[Bill Dunn]

it almost sounds like it could be the tach feedback in the servo. I had a beech in the shop that had an oscillation in the roll and that was the cause. did you avionics shop hook the KFC 200 up to the KTS150 test set and make the gain adjustments? there are a ton of things that come into play.

 

If I were to bring it in our shop I would hook it up to the test set and check the voltages everywhere while performing the alignment procedure.

[Awful_Charlie]

After the trimming is done, altitude hold is kept by a pressure capsule on the KFC150. The odd vertical hiccup would be down to water in the static line or similar - does the altimeter jump and the same time you get the vertical jolt? (just to make it clear, I know nothing about the KFC200)

[mbmaksymdc10]

Ok here we go

First check all static lines for leaks and water

Then check the alt air connections they installed mine backwards

These thinks happened to me also and the installer will say within limit

But they can be corrected with more work if you want to pay

If you say the aircraft not flying correct the FAA would so don't fly it

And it's a civil matter

So the installer has you and me Pay and pay

What us light aircraft owners need ,be it radio work ,engine work , a paint jog etc , is a organization that has money ,clout to go after these shops

I for one would join in a minute

Yes there is great organizations out there for pilot things but not one to help when it comes to maintenance

And your aircraft is pieces or the installation of equipment is only half right