KFC-200 Nav Offset?

[mulro767]

Can't figure this one out. When flying direct to a point and my KFC200 in NAV mode, my flight director commands a slight turn to the right until it is parallel to the course by about 1 mile. Then it holds the course steady. Any suggestions or quick fix?

[Seth]

I think but I'm not sure that it's an adjustment (literally by adjusting a few screws) to ensure the aircraft is flying straight and level. 

 

I had an issue where I was always one dot to the left during early ownership of my bird (1st hour) and as part of the checkout, I had Modern Avionics at KFCM - Flying Cloud, MN, fix the issue before I flew back to maryland.

 

The owner of Mondern Avionics with me in the plane, taxied to a flat area, and then engaged the autopilot on the ground.  The yoke then commanded a slight left turn.  He unscred the control module (KFC200) and slid it out partyway from the tray, made the screwdriver manual adjustments until the yoke did not have  tendancy to turn left or right.  Since then, the dot has remined pretty much centered except in some higher wind conditions, but it then corrects. 
 

My guess is that if you taxi out to a flat area and engage the autopilot to hold you straight and level, it may command a slight turn to the left (as that's where the dot indication is for your airpalne).  That's how you'll know if it's set up properly.  It's an analog system that may have simply in turbulance or over time slightly unsrewed a bit in the adjustmenet area.

 

This may be the fix - You're lucky - they guy who fixed my KFC200 is not to far from you, but he is far from me now (based in MD).  Call modern avionics at FCM - you're in the same state maybe 20 minute drive from FCM.

 

-Seth

[Piloto]

Try this first: remove the KFC-200 from its tray and spray contact cleaner on the contacts and reinstall. The course deviation voltage is very low +150mv and any small resistance can induce a deviation. 

 

José

[gsengle]

There is another possibility.  When my AI started to die (and then needed an overhaul) what would happen is that it would slump a bit to one side.  This would steer us off to one side, until it was balanced by the wind correction logic holding us back the other way...  So it was an early symptom of needing an AI overhaul...

 

g

 

 

Can't figure this one out. When flying direct to a point and my KFC200 in NAV mode, my flight director commands a slight turn to the right until it is parallel to the course by about 1 mile. Then it holds the course steady. Any suggestions or quick fix?

image.jpg

[thinwing]

That AI is very expensive to overhaul...I decided to upgrade to a g500 instead

[mulro767]

Thanks guys! I'll give Kurt a call at Modern Avionics. I'm based at FCM now. Hopefully a simple fix and not an overhaul. My plan is to upgrade to aspen when the time comes to overhaul.

[Marauder]

Another thing is to make sure your GPS is not setup to run a parallel course. It is an option on the GTN series.

[Bennett]

Marauder is right about the GTN 750.  If you are in NAV mode on your  autopilot, and you are following a flight plan, there is a setting to choose an offset distance.  Some old time pilots prefer to stay slightly offset from a commonly used Victor airway as a anti-collision methodology. The new avionics boxes steer right down the middle of a line drawn between two VORs, or down a Victor airway, and everyone is doing the same.  

[gsengle]

I thought so too, but I really like the king instruments - kind of like a swiss watch.  I got mine overhauled for about $2500 if I remember correctly, which was way cheaper than going Aspen...  I'm saving my money for engine overhaul

 

g

 

 

That AI is very expensive to overhaul...I decided to upgrade to a g500 instead

[Seth]

Marauder is right about the GTN 750.  If you are in NAV mode on your  autopilot, and you are following a flight plan, there is a setting to choose an offset distance.  Some old time pilots prefer to stay slightly offset from a commonly used Victor airway as a anti-collision methodology. The new avionics boxes steer right down the middle of a line drawn between two VORs, or down a Victor airway, and everyone is doing the same.  

 

+1  I think flying offset by a bit or so is a huge safty factor as the space around a victor airway is cleared for the MDA and this way it's not exacty where the majority of aircraft fly.  When I hand fly, I used to not care about being RIGHT on the purple line, but in the current aircraft when using auto pilot, I admit I'm dead center.

 

-Seth

[jlunseth]

I agree on seeing Kurt about it.  Modern does all my avionics work (except the JPI which was installed by Willmar).  He is very good and will treat you well.

[Seth]

Yes - Kurt is the guy

 

-Seth