Maybe most folks here don't remember the days when we flew with microphones
only. There was no provision for headsets and we didn't wear 'em. When
headset came to general aviation (probably because we were all going deaf)
they had to provide another receptacle for the ear phones. That socket had
to be a different diameter so the two couldn't be confused or mixed up.

Rod
"BTIZ" wrote in message
news:MdZwd.104$iD.82@fed1read05...
of all the posts.. I have not seen an answer as to why.. but simply
confirming that they indeed are different.

Military headsets have a different microphone impedance and different
headset capabilities.. microphones have to be right on the lips to pick up
the voice, so as not to pick up the aircraft noise. I few military for
twenty years, had my "issue" helmet and headset, and also my civilian
headset for personal flying.

I tried the adapter at one time, by with my military headset in a civil
setting, the mic would not work and only one side of the speakers.

Maybe they are different because the military did not want to mess with
two
cords? two jacks? and many times I've had to swap headset to helmet and
cannot see where the plug in is to swap out but had to go by feel. Why
mess
with two different sized plugs when one will do.

Many "civil" aircraft allowed a hand mic and public speaker combination so
you did not have to wear a headset, to do that would require two plugs,
one
mic, one speaker. Or an intercom panel switch to allow you to select the
speaker output.

BT

"Ben Hallert" wrote in message
oups.com...
Howdy,

Just started taking flying lessons (6 hours ground and 7 hours in the
air) and I've been reading up on everything like accessories,
techniques, etc plus lurking here for a week.

During this time, I noticed the difference between military andcivilian
headsets, and if I understand correctly, the military headsets are a
single plug versus the two plug civilian ones.

I've searched the newsgroup for an explanation why the civilian sector
hasn't switched to single plug system too? It seems like it would make
things easier, less points for failure, etc.

I understand that there's a lot of built in support for the existing
two plug system, but I'd expect the civilian radios to start having
support for both while everyone switched over over a 20 year or so
period.

Is that the case? Do new radios have both types of plugs? Or is there
another reason why civilian headsets use the two plug system?

Thanks!