Almost NORDO with stuck mike during IFR flight with extreme rain and convective SIGMET.

[Fly_M20R]

I was on an "escape" mission from a major front chainsawing across North and Northeast FL to get back to home base. In the process ended up flying through a band of extreme rain (but thankfully not a thunderstorm) and then had an intermittent stuck mike for the rest of the flight while dodging weather, etc.

A lot of you might wonder why I did not use a handheld. I actually always carry one in my flight bag. It's an older version of an iCom and I have adapters to connect with my BOSE LEMO plug as well as an antenna connector to plug into a jack below the panel that connects to COM 2 antenna. I started to assemble the spaghetti but found myself interrupted by further weaving and dodging as well as responding to ATC. A bit too long to put together for a relatively short flight (less than 45 min). I just kept on flying....

A bit of a stressful flight 

When you watch the video you will be just as annoyed as I was by the constant intermittent stuck mike!!!

Chris

 

 

[ArtVandelay]

If it’s the PTT switch, then just use the copilot’s switch. If it’s the radio, use com2.

[Fly_M20R]

20 minutes ago, ArtVandelay said:

If it’s the PTT switch, then just use the copilot’s switch. If it’s the radio, use com2.

Had done that in prior flight to no avail. Avionics shop went through all the wiring and found all well grounded and PTT switches intact. Thought it had been fixed but reared ugly head in this flight. It was the audio panel (GMA35c). RMA'd it and no issues w new replacement. Next time (hopefully never) I'll just pull the audio CB and use default COM2 as I mentioned in the intro.

[Ragsf15e]

2 hours ago, Fly_M20R said:

Had done that in prior flight to no avail. Avionics shop went through all the wiring and found all well grounded and PTT switches intact. Thought it had been fixed but reared ugly head in this flight. It was the audio panel (GMA35c). RMA'd it and no issues w new replacement. Next time (hopefully never) I'll just pull the audio CB and use default COM2 as I mentioned in the intro.

Another option in case it gets too distracting and you need 100% attention on flying is to squawk 7600.  Maybe not pretty, but follow the IFR routing/altitude hierarchy until you land at your destination or become vmc and can land somewhere else.  People have crashed focusing on communicating when they shouldn’t.

[Fly_M20R]

5 minutes ago, Ragsf15e said:

Another option in case it gets too distracting and you need 100% attention on flying is to squawk 7600.  Maybe not pretty, but follow the IFR routing/altitude hierarchy until you land at your destination or become vmc and can land somewhere else.  People have crashed focusing on communicating when they shouldn’t.

I thought about it, however since they could hear and understand me I also thought I could relay my intentions so they would not be totally blind and have no clue as to how to divert traffic around me. 

[whiskytango]

22 hours ago, Ragsf15e said:

Another option in case it gets too distracting and you need 100% attention on flying is to squawk 7600.  Maybe not pretty, but follow the IFR routing/altitude hierarchy until you land at your destination or become vmc and can land somewhere else.  People have crashed focusing on communicating when they shouldn’t.

This ^^^^.  I once lost the ability to transmit, due to rain water leaking into the radio stack, but was able to receive ATC.  After squawking 7600, ATC came back with "N231PG squawking 7600, advise if you can hear me by squawking IDENT".  ATC confirmed that they received my IDENT, and we were able to "communicate" the full IFR flight with handoffs and altitude assignments, etc. to destination.  After landing I phoned the local TRACON to thank them for the fantastic job they and the other sectors did keeping me safe!  

[PT20J]

Kind of hard to troubleshoot while in the thick of things, but some points to remember for the future:

1. Modern radios have a visual transmit indicator so you can tell if it is a transmit or receive problem. If you are really anal, a lot of radios (I know for sure on the GTN and GNC) allow you to set the sidetone so you are hearing your actual RF transmission demodulated rather than just amplified mic audio.

2. Most radios time out after a continuous transmission of 30 seconds or so to protect from overheating, so if the mic button is truly stuck, it will only jam the frequency for that time.

3. Most audio panels will failsafe to a direct headset connection to Com 1 if you pull the audio panel breaker.

4. Some Mooneys have a emergency mic and phone jacks wired to Com 1.

Never hurts to think through various scenarios and write up a little emergency checklist. The big guys call it a QRH - Quick Reference Handbook.

Skip

[Fly_M20R]

1 hour ago, whiskytango said:

This ^^^^.  I once lost the ability to transmit, due to rain water leaking into the radio stack, but was able to receive ATC.  After squawking 7600, ATC came back with "N231PG squawking 7600, advise if you can hear me by squawking IDENT".  ATC confirmed that they received my IDENT, and we were able to "communicate" the full IFR flight with handoffs and altitude assignments, etc. to destination.  After landing I phoned the local TRACON to thank them for the fantastic job they and the other sectors did keeping me safe!  

ATC is really helpful in cases like yours and mine! Glad all turned out great!

[Fly_M20R]

29 minutes ago, PT20J said:

Kind of hard to troubleshoot while in the thick of things, but some points to remember for the future:

1. Modern radios have a visual transmit indicator so you can tell if it is a transmit or receive problem. If you are really anal, a lot of radios (I know for sure on the GTN and GNC) allow you to set the sidetone so you are hearing your actual RF transmission demodulated rather than just amplified mic audio.

2. Most radios time out after a continuous transmission of 30 seconds or so to protect from overheating, so if the mic button is truly stuck, it will only jam the frequency for that time.

3. Most audio panels will failsafe to a direct headset connection to Com 1 if you pull the audio panel breaker.

4. Some Mooneys have a emergency mic and phone jacks wired to Com 1.

Never hurts to think through various scenarios and write up a little emergency checklist. The big guys call it a QRH - Quick Reference Handbook.

Skip

Great points Skip!!

[ilovecornfields]

7 hours ago, PT20J said:

Modern radios have a visual transmit indicator so you can tell if it is a transmit or receive problem. If you are really anal, a lot of radios (I know for sure on the GTN and GNC) allow you to set the sidetone so you are hearing your actual RF transmission demodulated rather than just amplified mic audio.

Any idea how to set this up on a GTN 750?

[PT20J]

9 hours ago, ilovecornfields said:

Any idea how to set this up on a GTN 750?

I've only done this on my GTN Xi, but I'm pretty sure the 750 works the same way. First, a GMA 35 can be set to either use the sidetone from the coms or generate it's own, so you have to make sure it is not set for internal sidetone. Then, you can set the GTN sidetone to external. The default for the GMA is to use external sidetone and the default for the GTN is also external, but the sidetone audio quality is better if you use the internal settings, so installers often set it up this way. In fact, Garmin recommends changing the GMA 35 setting to have the audio panel generate the sidetone.

To check it, enter configuration mode on the 750 by holding down the HOME button while powering up the unit the Garmin Logo appears.

If you have a GMA 35, navigate to the Audio Panel Configuration page and set "Audio processor generates COM1 sidetone" to FALSE.

Then go to the COM Configuration page and set Sidetone source to EXTERNAL.

Skip

 

[Oscar Avalle]

Nice job! Of course there are always things you could have done differently. But congratulations under the conditions you were, you mastered it!

 

And as usual great video.

 

Oscar

[Fly_M20R]

Thank you Oscar!

Yep, could've... should've... would've...!!!

Chris