LGT HAS BRIEF PERIOD OF LOST COM DUE TO STUCK MIKE.

Narrative

COM WITH ZOA MAY HAVE BEEN LOST DUE TO A STUCK MIKE AND THE OBSERVERS AUDIO SELECTOR PANEL. THE PLT AND COPLT AUDIO SELECTOR PANELS WERE BOTH CHKED FOR A STUCK MIKE. A FEW MINS LATER; THE OBSERVER'S AUDIO SELECTOR PANEL WAS FOUND TO HAVE A HAND MIKE PLUGGED IN WITH THE #1 UHF MIKE SELECTED. REMOVING THE HAND MIKE FROM THE OBSERVER'S AUDIO SELECT PANEL CLRED THE AIRWAYS OR COM FOR THE FLT. UNLESS HAND MIKES ARE BEING USED; THEY SHOULD BE LEFT UNPLUGGED; HOWEVER; ALL AUDIO SELECTOR PANELS SHOULD BE EXAMINED AT THE SAME TIME. DURING THE MINS OF LOST COM AT FL240; A TCASII ALERT WAS RECEIVED FROM BELOW FL230 -- AN ACFT APPARENTLY CLBED TO THAT ALT. IN COMPLIANCE WITH FAR 91.185; A DSCNT TO CROSS CEDES INTXN ON THE MODESTO 2 ARR WAS ABOUT TO BE INITIATED. FL240 WAS MAINTAINED AND CODE 7700 WAS SELECTED WITH INTENTION OF SQUAWKING CODE 7700 FOR 1 MIN BEFORE CHANGING TO CODE 7600. IT WAS DURING THIS TIME THE COPLT WAS SUCCESSFUL IN RE-ESTABLISHING COM WITH ZOA. DISCOVERY OF THE HOT MIKE FOLLOWED AND SUBSEQUENTLY AN UNEVENTFUL ARR AND LNDG WAS ACCOMPLISHED.