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Kentucky Captain View Drop Down
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    Posted: 06 Dec 2019 at 4:27am
I was doing some approaches today and had a very strange error.

I was doing the RNAV 23 into KEKX today which is a very interesting approach in itself because it has two turns in the final approach course due to a restricted area.

I had flown this approach earlier in the day with no issues but on this approach, I suddenly got a full right deflection of the CDI needle even though I was still on the centerline.  I didn't have much time to troubleshoot but I was able to dump the approach and re-enter it as at vectors to final approach but I still got the same full scale needle deflection again.  I landed and shut down, then later took off again, headed back to my home airport.  I shot the RNAV 03 approach back into KBRY and all was normal.

Any indication as to what would cause this?  I didn't notice any RAIM warning.  I've never seen one, would they show up where all other messages display on the IDF?

I'm guessing that this was an error out of the IFD, not the Aspen.  I did update the JeppData prior to the first flight of the day but had no issues on the previous three approaches, one being the same approach that the error occurred on and no error on the one after shutting down.

My concern is that this might happen on an actual IMC approach.  Of course I would execute a missed approach, but what next?  Since I shut down at the airport, I'm not sure what it was that fixed it.  If I had to have execute a missed approach, would proper procedure be to shut down and restart the IFD?
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310pilot View Drop Down
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Points: 102 		Post Options Post Options   Thanks (0) Thanks(0)   Quote 310pilot Quote  Post ReplyReply Direct Link To This Post Posted: 10 Dec 2019 at 4:59pm
Hi there
Can’t answer as to the why but it does look like JEXUD is your active waypoint and the cdi is trying to take you there (which I’m guessing was behind you).... assuming you shot the full approach I have no idea why it didn’t sequence over Jexud
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Kentucky Captain View Drop Down
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Points: 234 		Post Options Post Options   Thanks (0) Thanks(0)   Quote Kentucky Captain Quote  Post ReplyReply Direct Link To This Post Posted: 10 Dec 2019 at 8:01pm
Originally posted by 310pilot 310pilot wrote:

Hi there
Can’t answer as to the why but it does look like JEXUD is your active waypoint and the cdi is trying to take you there (which I’m guessing was behind you).... assuming you shot the full approach I have no idea why it didn’t sequence over Jexud


I saw that and never made the connection.  I had departed my home base of KBRY and was only 20 miles from where I was going, KEKX.  I decided to run the approach in there since I was landing there anyway.  By the time I decided that I was already south of JBEAM but I think the only choices for the IFD are JBEAM, EWO, and VECTORS.  I entered JBEAM and then highlighted ZOMDA and selected direct.  It seems that the LDI gave me a good course from ZOMDA to JEXUD that then went all wonky.  I don't know what would cause it not to switch to the next fix.

I wonder why it didn't correct itself when I canceled the approach and re-entered it as VTF.  That should take out all of the waypoints.

Thanks.
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M20J View Drop Down
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I'm not sure about the first time - you don't specify how you loaded the approach or where on the approach you were when you got the full scale deflection. 

But you state that you then reloaded the approach as vectors to final, which will make JEXUD the active waypoint and I believe that loading VTF will then create a final approach course with a track of 240 to JEXUD i.e. straight-in to the FAF. Normally with other approaches this is fine, but with an approach like this one that actually has a turn at the FAF, it does not result in the correct final approach course. It makes sence to me that you would have a full scale right deflection in this case, since the actual approach course that you were following is left of the straight-in to the FAF that VTF creates.
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Kentucky Captain View Drop Down
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Points: 234 		Post Options Post Options   Thanks (0) Thanks(0)   Quote Kentucky Captain Quote  Post ReplyReply Direct Link To This Post Posted: 10 Dec 2019 at 11:09pm
Originally posted by M20J M20J wrote:

I'm not sure about the first time - you don't specify how you loaded the approach or where on the approach you were when you got the full scale deflection. 

But you state that you then reloaded the approach as vectors to final, which will make JEXUD the active waypoint and I believe that loading VTF will then create a final approach course with a track of 240 to JEXUD i.e. straight-in to the FAF. Normally with other approaches this is fine, but with an approach like this one that actually has a turn at the FAF, it does not result in the correct final approach course. It makes sence to me that you would have a full scale right deflection in this case, since the actual approach course that you were following is left of the straight-in to the FAF that VTF creates.


I believe you have it correct for the VTF.  As to the initial approach, I was about 5 miles due east of ZOMDA.  I had good needles till somewhere around JEXUD. Not sure if it went full scale before or after JEXUD.  I was by myself, VMC, and I believe I reloaded the approach inside of JEXUD just to see if I could get it to play nice.

I like to shoot that approach because of the bend in the middle.  I do remember at one time there was a note from Jeppesen about issues with approaches that had a bend like that but I think it got resolved over a year ago.

There is also a VOR DME Arc approach at another airport a little southeast (6I2) that is fun to do.
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