IFD 5 Series & IFD 4 Series Touch Screen GPS/NAV/COM - IFD 440 and GDL82 Failing ADS-B SIL

IFD 440 and GDL82 Failing ADS-B SIL

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=1731
Printed Date: 06 May 2025 at 3:43am
Software Version: Web Wiz Forums 12.01 - http://www.webwizforums.com

Topic: IFD 440 and GDL82 Failing ADS-B SIL

Posted By: markpavinich
Subject: IFD 440 and GDL82 Failing ADS-B SIL
Date Posted: 25 Apr 2019 at 5:03pm

Need help with the particular scenario:

IFD440

GDL82

Configured ADS+B G2 format

SIL is failing almost at 100%

Everything else passes without any issuess.

On the ground, everything appears to check out.

Let me know if I am missing anything.

Thanks.

Replies:

Posted By: AviSteve
Date Posted: 26 Apr 2019 at 9:18am

Tech support says that the IFD440 is not an approved position source for the GDL82. That's why it's failing the SIL and is not covered by our STC.

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Steve Lindsley
Avidyne Engineering

Posted By: eallevato
Date Posted: 28 Apr 2019 at 4:37pm

Steve

Something does not seem right. The IFD440 according to Avidyne is a slide in replacement for the 430W. To me, that means that it is form, fit and functionally equivalent to the 430W. Tech support’s answer basically says “well, we are almost functionally equivalent”.

SIL is a function of the transponder and in this case the GDL82. It seems to me that the GDL82 is not configured correctly.

I would go back and ask engineering, instead of tech support.

Gene

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Gene

Posted By: mfb
Date Posted: 28 Apr 2019 at 7:06pm

I don’t think that this is an Avidyne thing. It’s a Garmin thing. They control the GDS 82, and they don’t approve position sources other than their own equipment.

See their official approval list at http://static.garmin.com/pumac/190-01533-00_06.pdf" rel="nofollow - http://static.garmin.com/pumac/190-01533-00_06.pdf .

The document states that any other position sources must meet the requirements of AC 20-165B. I have no idea what’s involved with establishing that, but I imagine it’s not trivial and it will be hard to do without Garmin’s cooperation.

Note that Avidyne DOES approve Garmin position sources for the AXP340 transponder, but the reverse is not true.

Mike

Posted By: Cruiser
Date Posted: 28 Apr 2019 at 10:56pm

from the FAA AFS-360 requirements

How can the ADS-B OUT system obtain initial approval?

Initial ADS-8 OUT system pairings (transmitter/GPS) must be approved for installation using

the Type Certificate (TC), Amended TC (ATC), or Supplemental Type Certificate (STC)

process. Consult your Aircraft Certification Office to determine the appropriate approval process

for these initial installations. Once the performance of the initial pairing has been established,

the FAA considers follow-on installations of the same pairing to be approved.

Organization Designation Authorization (ODA) holders can issue ATC and STC when

authorized by their FAA Organization Management Team (OMT).

Posted By: Cruiser
Date Posted: 28 Apr 2019 at 10:59pm

Don't all GDL 82 units come with an internal GPS source?

sounds like the only option is to mount the included GPS antenna and run the cable to the unit. Most of them are installed that way.

Posted By: eallevato
Date Posted: 29 Apr 2019 at 11:14am

The 82 comes in 2 flavors, with and without internal GPS.

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Gene