G1000 Radio Question

[Alan Maurer]

Hello Mooney People...My M20R Ovation from 2008 has an intermittent problem with #1radio. Told it was very scratchy. We tried switching antennas to see if the problem would go over to #2 radio but it stayed with #1. Now our avionics shop ( Sarasota Avionics) says ,  having obtained an exchange radio from Garmin that when the two #1 radios are switched, that the G1000 software (via Mooney and Garmin) has to be revised, which I am told takes four hours. In the past have been told to avoid doing anything with the Garmin G1000 software as it can cause big problems. Sarasota Avionics agrees it is not without problems but can be done. I would like to know what experiences anyone has had with this as I am worried that it will create a disaster. maybe better to keep a not so great radio. Thanks....Alan....N913ND

[philiplane]

They do not have to load the entire system software for a single LRU swap. They only need to load that specific unit with the same software version that is in the plane now. Single LRU swaps are covered in the G1000 Line Maintenance Manual, which is what they should be using. There is a checklist to ensure they don't miss loading any additional items such as the autopilot and other options. It should take about an hour to swap the unit and load the files, and test the system afterwards. 

G1000 software work can be tedious, but upgrading to the latest version is always recommended. Most upgrade problems are created by techs who don't follow the book. And by some who don't use a good ground power supply while loading the system. If you follow the book, it is not difficult. The very first thing they are supposed to do, is often skipped. That is to take screenshots of the system configuration before changing anything. If they don't, they can miss loading the optional items. The structure is such that you have a base software, then add options like autopilot, XM weather, traffic systems, etc.

Roughly one hour is needed for single component swaps, and up to 3 hours if loading everything from scratch.

Edited June 9, 2022 by philiplane

[Alan Maurer]

Thank you… seems very scary

[Ragsf15e]

5 hours ago, Alan Maurer said:

Hello Mooney People...My M20R Ovation from 2008 has an intermittent problem with #1radio. Told it was very scratchy. We tried switching antennas to see if the problem would go over to #2 radio but it stayed with #1. Now our avionics shop ( Sarasota Avionics) says ,  having obtained an exchange radio from Garmin that when the two #1 radios are switched, that the G1000 software (via Mooney and Garmin) has to be revised, which I am told takes four hours. In the past have been told to avoid doing anything with the Garmin G1000 software as it can cause big problems. Sarasota Avionics agrees it is not without problems but can be done. I would like to know what experiences anyone has had with this as I am worried that it will create a disaster. maybe better to keep a not so great radio. Thanks....Alan....N913ND

Did they check the swr to check the quality of the antenna and wiring? Easiest way to get some static is a faulty connection or bad ground on your antenna. I’m no expert, but that’s what I’ve read and checking that seems easier than starting with the lru swap.

[Alan Maurer]

Hi 

what do those two abbreviations 

stand for?

[StevenL757]

@Alan Maurer,

SWR = Standing Wave Ratio.  Overview here:  https://www.sciencedirect.com/topics/engineering/standing-wave-ratio

LRU = Line Replaceable Unit.  Your GIA63W radio modules located in the avionics bay, for example, are considered LRUs.  Basically any computer that generally slides into/mounts into a rack in the remotely-mounted area/areas away from the cockpit that connect back to the cockpit in one or more forms to one or more systems.

Edit:  Send me a PM and I’ll reply with my number and we can talk tomorrow if this issue persists.

Steve

Edited June 10, 2022 by StevenL757

[StevenL757]

Switching antennas really isn't going to tell you anything.

Before you go ordering replacement/exchange radios, you should be switching the GIA63W units and setting them both Active/Active in the software (through the config - a dealer needs to do this).

1.  If the problem moves, it's something other than the GIA63W

2.  If the problem DOESN'T move, it's likely the GIA63W

@philiplane's comments are well-taken.  If you have a GTX345R, then your SW load will be a bit more involved as its imaging SW needs updating also.  An active traffic system (TAS/TCAS) onboard adds more complexity.  Essentially, you need to know EVERYTHING you have on board your airplane and how it connects to understand and know how to make a good problem statement to your shop.

[philiplane]

It is rarely the antenna. On some occasions, it might by a faulty coax connection at the antenna, due to bending the cable over and piercing the center conductor to the shield. Or salt corrosion. In 25 years of avionics work, I've replaced three antennas, and those had obvious physical damage. 

The GIA's are divided into three sections: a com section, a nav radio section, and the GPS section. Any of the three can have a fault while the rest of the unit works fine. The com section is further divided into a transmit side, and a receive side. It's common for one half to go bad.

You can swap 1 and 2 for testing, which will require 2-3 hours total. But you will probably just confirm that the com radio needs service. You can send the GIA to Garmin for repair(2 weeks), or you can get an exchange overhauled unit which will come with a 2 year warranty. There's not much savings with a repair and there will be more downtime.

Edited June 10, 2022 by philiplane