Strange IFD440+KFC200 behavior

Message Topic Search Topic Options Post Reply Create New Topic Printable Version Translate Topic

   Hi everyone! I am hoping to dig someone's brain on an interesting problem (for me at least 😃)!
Recently I had fitted an IFD440 and APX340 coupled with KFC200 + KI525 (HSI) + KI256 (with FD)
After some initial testing of the unit, we noticed that the A/P always track 30 degrees to the left the course set. 
We tried the following scenarios

IFD setting     A/P mode
____________________

VLOC (green)  NAV/CPLD
GPS                   NAV/CPLD
RNAV                APPR / CPLD

The AP will always turn and hold the plane 30-degree left of the track. This is despite the CDI course set correctly and the deviation is - correctly - slowly moving to the right. The FD is definitely commanding. The CDI course deviation is accurate. The HDG mode is working fine. I never had tried flying any of the above mentioned mode as I am VFR only so I don't know if they are working properly before. Me bad!

My shop bench tested the HSI and no faults were found. Wonder what other potential causes for this?

Thanks guys

Author	Message Topic Search Topic Options Post Reply Create New Topic Printable Version Translate Topic
tommy Members Profile Send Private Message Find Members Posts Add to Buddy List Newbie Joined: 17 May 2018 Location: Australia Status: Offline Points: 9	Post Options Post Reply Quote tommy Report Post Thanks(0) Quote Reply Topic: Strange IFD440+KFC200 behavior Posted: 29 May 2018 at 8:11am
	Hi everyone! I am hoping to dig someone's brain on an interesting problem (for me at least 😃)! Recently I had fitted an IFD440 and APX340 coupled with KFC200 + KI525 (HSI) + KI256 (with FD) After some initial testing of the unit, we noticed that the A/P always track 30 degrees to the left the course set. We tried the following scenarios IFD setting A/P mode ____________________ VLOC (green) NAV/CPLD GPS NAV/CPLD RNAV APPR / CPLD The AP will always turn and hold the plane 30-degree left of the track. This is despite the CDI course set correctly and the deviation is - correctly - slowly moving to the right. The FD is definitely commanding. The CDI course deviation is accurate. The HDG mode is working fine. I never had tried flying any of the above mentioned mode as I am VFR only so I don't know if they are working properly before. Me bad! My shop bench tested the HSI and no faults were found. Wonder what other potential causes for this? Thanks guys

Gring Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 30 Dec 2011 Location: Kingston, NY Status: Offline Points: 739	Post Options Post Reply Quote Gring Report Post Thanks(0) Quote Reply Posted: 29 May 2018 at 10:00am
	I have this setup in my Bonanza (IFD540). A couple of thoughts: 1) In the maintenance screens, check to see that when the CDI needle is set to 150 deg the IFD says it is 150deg. If not, follow the instructions to sync the two then check every 30 degrees. The two should match. 2) Once the KFC200 aligns with the course, it switches mode and only follows the deviation of the CDI, not the actual heading direction. You may have a KFC200 problem.

tommy Members Profile Send Private Message Find Members Posts Add to Buddy List Newbie Joined: 17 May 2018 Location: Australia Status: Offline Points: 9	Post Options Post Reply Quote tommy Report Post Thanks(0) Quote Reply Posted: 29 May 2018 at 6:19pm
	Thanks Gring! Which "section" or page should I be of the maintenance screen to do that? Do you have the manual or a link to it on how to sync the two? Thanks, Gring! Really appreciate it

tommy Members Profile Send Private Message Find Members Posts Add to Buddy List Newbie Joined: 17 May 2018 Location: Australia Status: Offline Points: 9	Post Options Post Reply Quote tommy Report Post Thanks(0) Quote Reply Posted: 30 May 2018 at 9:12am
	Actually, I loaded into the the maintenance page and saw the sync page. They are already in sync. :( Looks like it's not going to be a cheap fix then. Come to think of it, it does appear that my KFC 200 isn't really following the deviation of the CDI at all. It just wants to track 30 degree to the left of the CDI course. The Course selector on my HSI is acting like a heading bug. :(

Gring Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 30 Dec 2011 Location: Kingston, NY Status: Offline Points: 739	Post Options Post Reply Quote Gring Report Post Thanks(0) Quote Reply Posted: 30 May 2018 at 9:26am
	To verify, try tracking a VOR inbound and see if it continues to show the same behavior.