Narrative:

Upon climb out from bwi and talking to baltimore departure control, we began to notice what seemed to be too much silence on the radios and only receiving partial xmissions from the controller. As I recall, either bwi departure or washington approach (which was the next frequency) got through to us that we may have a stuck microphone on board our aircraft. Because I was the person on the radio for this flight, I pulled the microphone jack out to take my microphone out of the loop. This appeared to do no good. Next we pulled the first officer's microphone out of its jack and still seemed to be having broken xmissions and silence from ATC. At this point we began squawking 7600 and pulled the microphone on the observers mask microphone. The next step was to try the first officer microphone in the captain's jack. Once we did that, the problem seemed solved. I don't know if these problems created any traffic conflicts for the controllers. We tried to resolve the problem as quickly as we could but we had several anxious mins before we got communications back to normal. Because we are so dependent on a verbal ATC system, a possible solution to avoid stuck microphone problems would be to require all aircraft operators to install a visual transmit indicator in the cockpit, so at least you could tell if your radio is transmitting when it's not supposed to be.

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Original NASA ASRS Text

Title: MLG DEPARTING BWI LOSES COM WITH BWI DEP CTL DUE TO STUCK MIKE PROBLEM IN ACFT THAT WAS SOLVED BY USING THE FO'S MIKE IN THE CAPT'S MIKE JACK.

Narrative: UPON CLBOUT FROM BWI AND TALKING TO BALTIMORE DEP CTL, WE BEGAN TO NOTICE WHAT SEEMED TO BE TOO MUCH SILENCE ON THE RADIOS AND ONLY RECEIVING PARTIAL XMISSIONS FROM THE CTLR. AS I RECALL, EITHER BWI DEP OR WASHINGTON APCH (WHICH WAS THE NEXT FREQ) GOT THROUGH TO US THAT WE MAY HAVE A STUCK MIKE ON BOARD OUR ACFT. BECAUSE I WAS THE PERSON ON THE RADIO FOR THIS FLT, I PULLED THE MIKE JACK OUT TO TAKE MY MIKE OUT OF THE LOOP. THIS APPEARED TO DO NO GOOD. NEXT WE PULLED THE FO'S MIKE OUT OF ITS JACK AND STILL SEEMED TO BE HAVING BROKEN XMISSIONS AND SILENCE FROM ATC. AT THIS POINT WE BEGAN SQUAWKING 7600 AND PULLED THE MIKE ON THE OBSERVERS MASK MIKE. THE NEXT STEP WAS TO TRY THE FO MIKE IN THE CAPT'S JACK. ONCE WE DID THAT, THE PROBLEM SEEMED SOLVED. I DON'T KNOW IF THESE PROBLEMS CREATED ANY TFC CONFLICTS FOR THE CTLRS. WE TRIED TO RESOLVE THE PROBLEM AS QUICKLY AS WE COULD BUT WE HAD SEVERAL ANXIOUS MINS BEFORE WE GOT COMS BACK TO NORMAL. BECAUSE WE ARE SO DEPENDENT ON A VERBAL ATC SYS, A POSSIBLE SOLUTION TO AVOID STUCK MIKE PROBLEMS WOULD BE TO REQUIRE ALL ACFT OPERATORS TO INSTALL A VISUAL XMIT INDICATOR IN THE COCKPIT, SO AT LEAST YOU COULD TELL IF YOUR RADIO IS XMITTING WHEN IT'S NOT SUPPOSED TO BE.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.