IFD 5 Series & IFD 4 Series Touch Screen GPS/NAV/COM

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How to inhibit terrain warnings

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=2491
Printed Date: 13 May 2025 at 9:49am
Software Version: Web Wiz Forums 12.01 - http://www.webwizforums.com

Topic: How to inhibit terrain warnings

Posted By: cavu
Subject: How to inhibit terrain warnings
Date Posted: 01 Apr 2023 at 11:09am

Recent InFO serves to inform operators about the risks associated with distraction and complacency brought about by routine use of the TAWS’ terrain inhibit feature. It is also intended to ensure operators understand the importance of having procedures and training for the use of the terrain inhibit aural warning switches associated with nuisance alerts.

Can you describe procedure for inhibiting terrain warnings inflight to comply with this InFo?

Replies:

Posted By: Gring
Date Posted: 01 Apr 2023 at 6:10pm

I have installed the Mid Continent MD41 TAWS annunciator (sourced from eBay for $100) and it is wired to my IFD using the discrete outputs for lighting TAWS warning and caution. included is an inhibit button that will turn off the warnings. There have been some improvements in the 10.3.2.1 release over the older 10.2.X.X versions and it now works well.

Posted By: brou0040
Date Posted: 10 Apr 2023 at 11:23pm

https://www.faa.gov/other_visit/aviation_industry/airline_operators/airline_safety/info/all_infos/info23003

There is a pin that you can connect to a switch that will inhibit terrain warnings. This is very useful for anybody who flies around mountains. I get that they don't want people using it, but I'm not sure they'd have the same opinion if they regularly flew in the mountains and had the warning going off all the time.

I don't fully agree of the info because they are suggesting you should tolerate nuisance and distraction warnings in case someday they are useful. This ignores how pilots will become desensitized and that the warnings won't be effective when not inhibited.

I'm not 135, but I have a pre-flight checklist item to disable the inhibit terrain warning switch.

Posted By: Melohn
Date Posted: 11 Apr 2023 at 9:10pm

brou0040 wrote:

https://www.faa.gov/other_visit/aviation_industry/airline_operators/airline_safety/info/all_infos/info23003

There is a pin that you can connect to a switch that will inhibit terrain warnings.

This pin appears to only be available in the IFD 5xx series. There should be a way to mute excessive or incorrect terrain warnings; I use this frequently with my KGP 560, which gets confused occasionally and expresses a concerning “pull up” warning that bothers passengers.