IFD 550 / glide slope (LOC) issues
Printed From: Avidyne
Category: Avidyne General
Forum Name: IFD 5 Series & IFD 4 Series Touch Screen GPS/NAV/COM
Forum Description: Topics on Avidyne's IFD 5 Series and IFD 4 Series Touch Screen GPS/NAV/COM
URL: http://forums.avidyne.com/forum_posts.asp?TID=1343
Printed Date: 28 Apr 2025 at 4:48am
Software Version: Web Wiz Forums 12.01 - http://www.webwizforums.com
Topic: IFD 550 / glide slope (LOC) issues
Posted By: arkvet
Subject: IFD 550 / glide slope (LOC) issues
Date Posted: 28 Jun 2017 at 10:24am
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I went for my first IFR test flight yesterday using the new IFD. I have a mechanical HSI (NSD360) that is coupled to my AP (Century 41) and the IFD. RNAV approaches operated normal. Flew to two different airports to shoot an ILS and never could get the IFD to go from GPS->VLOC to VLOC mode . Nav mode stayed at "Term" and didn't go to "App". I believe all criteria were met. Needle was centered on a straight in approach from FAF and altitude was spot on. Magenta line was happy too;) I did not try to manually switch to VLOC (had to read up on that when I got home). I also am not 100% sure that the setting to automatically switch is set to "on" in the settings. I am fairly certain the Flight plan did not have any gaps or issues. I am going back up at lunch today. Will verify appropriate settings and even try the manual switch if necessary. I will also mention that one of the ILS approaches I tried gave me an alert that the identifier did not match which would obviously make it not capture... I verified the frequency. It should have matched. the other approaches did correctly identify so that wasn't the issue. I posted this over on Piper Forum initially thinking it might be an issue with my HSI, antenna, etc issue rather than a user issue with the IFD? Still could be. Orest suggested I post over here too. I will report back the findings. Maybe this trouble shooting will be useful to someone else as well. Any additional thoughts feel free to chime in. Thanks. ------------- Brent PA32-301 IFD550 / AXP322 / SkyTrax100 / Dual G5's / GFC 500 / JPI 830 |
Replies:
Posted By: Gring
Date Posted: 28 Jun 2017 at 2:15pm
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I think you need to verify your settings and deliberately fly an ILS using a checklist or test card so you can write down actual experience vs desired experience. For instance, you say you got a frequency mismatch message - did you verify frequency via audio? What about the IFD, did it decode it on the NAV frequency or data Lock? When tracing a problem, you really need a test card with you |
Posted By: arkvet
Date Posted: 28 Jun 2017 at 2:28pm
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Thanks Gring. Just got back from a test flight. Approaching the FAF (pretty far out) the LOC was accurately decoded. GPS-> VLOC was displayed at top. FAF came with no switch to VLOC. Made another pass and manually switched to VLOC via knob and Glideslope came alive and it showed VLOC in corner (GPS disappeared) App was displayed for both passes. The auto setting in setup was selected to on so it should have switched. At least I know the HSI and ability to shoot the approach is fine. It's the auto switch that didn't function. The frequency issue was at a distant airport and I didn't have time to go there at lunch today. That ILS was not decoded in the frequency bar but was checked for accuracy. I did not check it via audio. ------------- Brent PA32-301 IFD550 / AXP322 / SkyTrax100 / Dual G5's / GFC 500 / JPI 830 |
Posted By: AviSimpson
Date Posted: 28 Jun 2017 at 4:51pm
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I just want to confirm that you met the following criteria: -The ILS freq matches the approach navaid -The Morse code was decoded by the tuned nav radio and it matches the approach navaid. -The aircraft track is within 15 degrees of the final approach course -The course to the active waypoint is within 45 degrees of the final approach course -The deviations are at most 50% of full scale for 5 seconds -The active leg is part of the approach up to and including the FAF (Section 5-12 in the latest IFD540 PG and section 6-12 in the latest 550 PG) Since you mentioned that you aren't seeing the ILS identifier decoded by the IFD, that would indicate that you aren't receiving the station Morse code long enough (or at all) for the system to know that it's the correct Navaid. ------------- Simpson Bennett Avidyne Corporation Product Manager |
Posted By: arkvet
Date Posted: 28 Jun 2017 at 5:40pm
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All the criteria were met with the exception of audibly listening to the morse code. However, the frequency was decoded and identified long before reaching the FAF. This ILS was flown into a relatively sleepy non tower controlled airport. I was established on the final approach path well before reaching the FAF. When I manually switched to VLOC the deviations were both less than 50%. I am pretty confident there were no issue with the flight plan but will revisit those sections in the PG just to be certain. thank you. ------------- Brent PA32-301 IFD550 / AXP322 / SkyTrax100 / Dual G5's / GFC 500 / JPI 830 |
Posted By: George P
Date Posted: 28 Jun 2017 at 6:33pm
| My 540 does not switch over until right at the FAF, unlike the G 530 which switches once the localizer needle is pretty well centered. |
Posted By: arkvet
Date Posted: 29 Jun 2017 at 9:56am
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I intend to go back study my flight plan chapters again and try again. It could very well be user error I just can't seem to find where it went wrong. I am, however, blown away at how user friendly the gps is when entering FP's. I may be making mistakes but if so that's on me. This is so much more intuitive than the GNS530W. Thanks all. I will report back. ------------- Brent PA32-301 IFD550 / AXP322 / SkyTrax100 / Dual G5's / GFC 500 / JPI 830 |
Posted By: AviSimpson
Date Posted: 29 Jun 2017 at 10:31am
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I'm interested to hear what you find out. We recently (in the past year, I believe it was 10.1.3) made some enhancements in decoding the Morse code faster. ------------- Simpson Bennett Avidyne Corporation Product Manager |
Posted By: oskrypuch
Date Posted: 29 Jun 2017 at 11:16am
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There was also an issue with the LOC database, where it would remain unconfirmed (and stay yellow), as you didn't have all the LOC freg available, or something like that. I hit on a number of these. 10.2 seems to have fixed most of them, but I still see that (IIRC) at CYHM on the ILS. If you are interested, I can confirm the specifics of that. * Orest |
Posted By: AviSimpson
Date Posted: 29 Jun 2017 at 1:27pm
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Yes please, Orest. PM me or email me at sbennett(at)avidyne ------------- Simpson Bennett Avidyne Corporation Product Manager |
Posted By: arkvet
Date Posted: 29 Jun 2017 at 2:51pm
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OK so a portion of the mystery has been solved. Our original intended destination was KJBR ILS 23. When that one failed to grab the LOC and I didn't know to manually switch to VLOC my CFI suggested we go to an alternate (next nearest ILS) KBYH (Blytheville). That's the one where the frequency was correct but it would not decode and identify... Looked this am and there's a Notam that the ILS at KBYH is unavailable. I normally would have checked for Notams preflight but we hadn't intended on that ILS when we left. Good real life lesson for me! (under VMC which is the best time to learn!) ------------- Brent PA32-301 IFD550 / AXP322 / SkyTrax100 / Dual G5's / GFC 500 / JPI 830 |
Posted By: arkvet
Date Posted: 29 Jun 2017 at 2:55pm
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Question though: If the LOC has been correctly decoded should that coincide with GPS going to VLCO or could/would/should there be a delay before switching? ------------- Brent PA32-301 IFD550 / AXP322 / SkyTrax100 / Dual G5's / GFC 500 / JPI 830 |
Posted By: AviSimpson
Date Posted: 30 Jun 2017 at 3:02pm
Once all the conditions are met, there is a 5-second delay. ------------- Simpson Bennett Avidyne Corporation Product Manager |
arkvet wrote:Posted By: arkvet
Date Posted: 13 Jul 2017 at 10:18am
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Just wanted to toss out an update. I was able to get out yesterday and fly the ILS into KJBR. Everything worked beautifully. I believe on the first attempt my mistake was trying to intercept the LOC too close to the FAF. I shot a practice "vectors to final" and intercepted about 5 miles before the FAF and the auto transition to VLOC mode was perfect. Also, FWIW I finished the book (recommended on another thread) and it has been so helpful! Right now I'm trying to figure out what screens I want/need to have up during the different phases of flight for each the 550 and the IFD100 app. I really wish the data blocks would display on the right side of the IFD100 when in map mode like they do in the 550. I *think* my preference would be to have the IFD100 in map mode if that were the case and to display FMS/small map view on the 550. As of now I have that swapped due to the lack of data blocks on the IFD100. Minor nuisance though. Geesh I'm loving this thing! ------------- Brent PA32-301 IFD550 / AXP322 / SkyTrax100 / Dual G5's / GFC 500 / JPI 830 |