I have a garmin 430 non-WAAS in my 66 pa-30. When I select VLOC I get an off flag on the CDI for lateral guidance. I have tried numerous VOR's and VOR checkpoints, but still have the off flag and no guidance. Similarly, no lateral guidance on an ILS frequency. The glideslope works fine with no flag present. I have had an avionics technician test the equipment and he indicates that everything is working with his equipment. Has anybody experienced this problem? Thanks for any input!

John Wasserburger

We had a similar problem with our HSI. After numerous trips to the Avionics shop it was finally traced to an intermittent ground for the nav flag

I have the flag and no guidance also. The needle is centered up in the instrument and does not move. However, on the ground with the engines not running and while put on avionics test equipment it functions correctly.

John

Antenna problem?
-Zach

John, I have a non-WAAS 430 coupled to a Century HSI and have had this problem twice in about 3 years. The first time an HSI overhaul took care of it. Recently I experienced an invalid preflight test between the 430 and the HSI, and no navigation information was reaching the HSI. A bench test by the avionics shop of the 430 showed it was not communicating with the instrument. All other aspects of the 430 were fine. Later on I slid in another non-WAAS 430 and HSI did worked fine. The shop of course was unable to fix the 430 (referring to Garmin's policy of no support for non-WAAS units). I contacted my local avionics shop and was told (just repeating what they told me here now) that the unit would be repaired and upgraded to WAAS for the price of the upgrade. My options were few, so I sent if off for upgrade last week. You might try a bench test of your 430 or see if they have a loaner you can slide in and see how that one works. Don't take my word on the repair price though. I haven't received a bill yet, so I can't vouch for the shop's claim on one price for both upgrade and repair. Hope this helps and good luck.
Martin Moore

John, I had a similar problem only with my glide slope on my HSI fed by my 530. Tested fine on the ground but off flag in the air. It ended up being a loose coax connection on the back of the 530.

The posts here sound so familiar to those who work with electronics. At times something will become loose and the process of removing and reinstalling, re-seats the component and the problem goes away ... the owner and the technician call this no trouble found. Saw this a lot in the 70s and 80s with computers and saw it with a TV we used to have.

When we were both so busy working, the TV we watched the evening news on kept having cable problems.After many service calls and still intermittent problems, we bought a new TV and put that one in a different room. After I retired, I saw an ad for Sears who had a low service call price and would work on any TV in your home - good because this was a 150 pounder. Sears guy removed all the circuit cards, put them back in - said no trouble found and left - all worked perfectly until we sold it years later. What eventually dawned on me was the cable troubles in the old location came usually on Tuesday nights - the day we had help to clean the house. After we moved it, our cleaner help retired and I started doing all the cleaning - no more problems.

So if you think of any avionics work as someone else cleaning your house and flying as someone constantly but gently touching the attachments cables, the problems we're seeing become a little more understandable IMHO but no less easy to find the problem and fix it. Like the posts above, I'd check all connections - a daunting task.

Hi John,

Echoing prior comments, I recently had the os software on the 430 upgraded at the avionics shop. After the upgrade the tech went thru the test protocol and there was a problem with the cdi. He did not hesitate and took the top off the panel and "excercised" the connection to the cdi and presto all was well again. He said that after 10 yrs of not being moved the connection can get spotty. Easy fix and worth a try.

Good luck, Don

Mine ended up being a loose coax connection. Sorry for the late follow up!

John