Jake@BevanAviation

Having a better description of the issue might help narrow down where to start looking. Some good questions to ask would be. What are the flight bars doing? Is the issue only related to alt hold? How large is the change from target altitude? Has the bridal cable tension been checked? Can the system hold a 5 deg climb or descent? If the static line is removed from the KC-295 is the issue still present? Has the attitude source (KI-256) been changed recently? If your friend has a video of the issue that might help as well. Just be sure to have the ADI and annunciator in the shot. Also, knowing what series of pitch servo would help. Depending on the serial of the aircraft it could have the KS-270 or KS-177 pitch servo. If your friend would like to chat about the issue they can always give me a call.

The voltage monitor at P2 pin W is set by the adapter modules in the flight computer that are aircraft specific. There is a voltage range that the computer looks for when doing the PFT and will monitor this voltage during operation. If the voltage goes to low or drops out the computer will issue a fail annunciation as flashing trim. I have seen the voltage regulators in the trim servo get soft under a load like MET operation. If the regulator is in a no load environment the output will be sufficient to satisfy the computer. When the regulated voltage is used to drive up or down trim during MET operation the computer will sense this low voltage and issue a fail annunciation.

So things that will cause a TRIM fail annunciation are. No trim feedback within a time period after the computer has sent a auto-trim command. Trim feedback of the wrong polarity Missing regulated trim voltage at P2 pin W of the flight computer Auto trim drive with no command from the flight computer If you have been able to consistently duplicate the fail condition while using the MET (manual electric trim) switch on the yoke I would start there. Pay attention to the left side of the split rocker as it is the regulated voltage and disconnect signal side that is sent to the computer. There are small return springs in the MET assembly that can go bad over time or break. I have seen something similar before with after using MET the unit will not engage or will not pass PFT. After replacing the assembly the issue goes away.

If the KC192 won't PFT and has no annunciations I would be checking power and ground to the unit. There is also a small pico fuse inside the unit. If you have a -15 unit repair capabilities will be limited to 2 shops, Bendix King and Duncan Aviation. If it is the older -03 unit they can still be field repaired. I have seen the caps explode before and there is also a issue with units manufactured in the 93-97 year range where they will have capacitors leaking in the power-supply circuit. The circuit traces are so small in some of the areas that the electrolyte just eats up the trace. If you don't catch the cap leakage early on you can have a big problem with board damage.

Simple answer is no. The KAP vs KFC will have different adapter modules. If you were able to find the correct dash number of KC-192 with the correct modules then yes, you could remove one and install the other with some additional wiring for FD bars to the Aspen. The good news is the modules can still be made however, they are fairly expensive and can only be sourced from Duncan Aviation. If you could get a copy of the install manual for your aircraft it will have all the information you would need to source a as removed unit. NOTE: if you are going to swap be sure to align the new unit to the attitude source when installing.

First thought is you mention 4 flashing lights (trim) then nothing. Typically when this happens the unit is still stuck in self test mode and not issuing a fail or pass command. There are 2 relays on the top board that deal with the ramp rate test for attitude. I have seen these fail and produce the same result. If the unit has been removed from the rack I would suggest double checking the pins and re-racking the unit and then test again. The fact that you at least get some flashing lights means the unit is working just stuck somewhere in the PFT mode. If the shop has the flight line test kit i would suggest getting the unit out and testing it on the bench with the test chips. That should be able to narrow down the issue with the unit. NOTE: as long as the dash number is not -15 it will work with the flight line test kit. If your unit is a dash -15 the only shop that can test it is Duncan. The only think I can think of is maybe the EA100 could have a issue with the interconnect relay for attitude valid. If it is working properly you should get bus voltage on P2 pin B at the flight computer. Pushing the disconnect switch or the EA100 becoming invalid should remove this voltage.

A yoke mounted disconnect switch is optional equipment per the factory maintenance manual. Might be worth a call to Century to see if the optional part is still available.

Ideal startup voltage after overhaul or cleaning and bearing replacement is around 800mvDC. Typically anything above 2VDC is getting in the area of high startup voltage especially on a 14v system.

So the best way to adjust the roll threshold is to max out the pot until it produces a slight roll oscillation and then back it off until the oscillation stops. There is a product that Bob has suggested to me and I have started using that works wonders with connector pin issues. Stabilant 22, you can find it online. I have been using it for about a year and had great results.

Winchester connectors used to have a machined 4 pin female connector that worked great but I have not been able to locate the connector for some time. Using a small pick you can push the female split pins back together. Sometimes this will fix the intermittent issues that are connector related.

For the sticking solenoid I would have the tech check the travel of the solenoid and possibly adjusted the solenoid alignment so it doesn't get stuck when releasing. I have seen this happen in the older style of solenoids but in the revision they added a plastic insert to try and prevent this.

Double check that the gyro alignment was done on the new KI256 and have them look at the tach feedback from the roll servo. Tach generators in the roll servo can go bad and produce roll oscillations.

Seen it happen before in a JetPROP with a KFC 150 system. Turned out to be something wrong with the pitch servo. The aircraft flew fine the bars would just bounce all the time for pitch. Swapped the pitch servo out and the problem went away.

If the drive motor is running (pins C and D) the solenoid is on (pins A and B). A simple voltage check with the servo connector with a multi-meter will show where the issues is. With the meter on the ship side pins A and B (ground) when the roll rocker is pushed up the solenoid should get buss voltage. You can also test the servo with power-supply if needed. The 4 pin connector are notorious for being intermittent. If you are still having issues just give me a call and I will help with troubleshooting as much as possible.

If the attitude source has been change by replacing or repairing the KI256 the gyro gains need to be adjusted. This is done with the KTS 158 test set. Any shop that has this test set should be able to set the bank back to 20 degrees.

The KC 295 is still available for field service and is not required to be returned to the factory for repair. There are some components in the KFC 200 system (KS271A,KS272A) that would need to be repaired at a authorized repair center. Duncan Aviation, Mid-Continent Instruments, Southeast Aerospace and Precision Aero are the approved repair centers for certain components

Well if you have 2 KC 295 flight computer you could possibly make one good one out of the two if they are the same dash number. I would have to check specifics on board compatibility. If you have any questions just give me a call.

If that is the repair for just the KC-295 flight computer it seems excessive.

Good to hear that the adjustments to the radio coupler worked for you. If you have any additional issues just let me know.

It sounds like you were in a nav track mode where it limits the banks to 10 deg of correction. This is completely normal for nav track mode. The computer was designed to compute intercept angles for proper nav track. If you refer to that attached file page 40 it will outline how to set up the system for a RNAV intercept/capture. As long as the computer has the proper setup for intercept/capture you should not experience the shallow bank limit. KFC 200 Pilot Guide.pdf