Narrative:

Just prior to the time when all sectors would be combined for the midnight shift, I was controling sector 67, known as 'camrn' with sector 68, known as 'dixie' combined with it. There was no handoff controller. I had 2 flts on my frequency, 132.95, which were no factor to the incident. There was no WX, and visibility was unlimited. I received 3 departures, 1 from phl, air carrier Y. 2 other aircraft were handed off to me from new york TRACON. 1 was no factor to the incident, the other was air carrier X. Air carrier Y reported on the frequency, leveling at assigned altitude of 10000. He would enter my airspace in 6 mi at which time I told him he would get a higher altitude. I assigned the aircraft 'fly heading 080, vectors jfk.' air carrier X reported on the frequency, 'out of 8 for 10.' I answered and told the pilot the local altimeter. He read it back, and his radio became stuck in the transmit position, blocking the frequency. I was positive of the aircraft identification because of cockpit conversation and ultimately confirmation by the pilot after the event. I attempted to contact air carrier Y but received no response. He was on a heading now that would put him in conflict with air carrier X. I couldn't break through the transmission of air carrier X. I attempted broadcasting on guard frequency, 121.5, but received no response. An aircraft on another frequency was solicited to broadcast on my frequency to raise air carrier X, but received no response. We no longer have phone lines to FSS's, so we were unable to have flight service broadcast on a VOR frequency at coyle or kennedy. We watched helplessly as the 2 aircraft closed at an alarming rate: air carrier Y flight crossed in front of the air carrier X flight at the same altitude and 2 mi. By this time, air carrier Y returned to phl approach area for instructions. We had alerted phl approach and they assigned air carrier Y an alternate frequency. Air carrier X realized his mistake and cleared the stuck microphone. He apologized, and I said a few things about frequency alertness. I doubt that air carrier X had the frequency in a headset which would have alerted him to the problem. Also, I was told by quality assurance that when this has happened in the past, it was suggested a light be fitted in the cockpit when the pilot is transmitting. The airlines, however, ignore this suggestion, stating cost factors. I feel that ultimately, it will take a disaster to change their minds. One nearly took place here.

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Original NASA ASRS Text

Title: ACR X AND Y HAD LESS THAN STANDARD SEPARATION CAUSED BY STUCK MICROPHONE IN ACR X.

Narrative: JUST PRIOR TO THE TIME WHEN ALL SECTORS WOULD BE COMBINED FOR THE MIDNIGHT SHIFT, I WAS CTLING SECTOR 67, KNOWN AS 'CAMRN' WITH SECTOR 68, KNOWN AS 'DIXIE' COMBINED WITH IT. THERE WAS NO HANDOFF CTLR. I HAD 2 FLTS ON MY FREQ, 132.95, WHICH WERE NO FACTOR TO THE INCIDENT. THERE WAS NO WX, AND VISIBILITY WAS UNLIMITED. I RECEIVED 3 DEPS, 1 FROM PHL, ACR Y. 2 OTHER ACFT WERE HANDED OFF TO ME FROM NEW YORK TRACON. 1 WAS NO FACTOR TO THE INCIDENT, THE OTHER WAS ACR X. ACR Y REPORTED ON THE FREQ, LEVELING AT ASSIGNED ALT OF 10000. HE WOULD ENTER MY AIRSPACE IN 6 MI AT WHICH TIME I TOLD HIM HE WOULD GET A HIGHER ALT. I ASSIGNED THE ACFT 'FLY HDG 080, VECTORS JFK.' ACR X REPORTED ON THE FREQ, 'OUT OF 8 FOR 10.' I ANSWERED AND TOLD THE PLT THE LCL ALTIMETER. HE READ IT BACK, AND HIS RADIO BECAME STUCK IN THE XMIT POSITION, BLOCKING THE FREQ. I WAS POSITIVE OF THE ACFT ID BECAUSE OF COCKPIT CONVERSATION AND ULTIMATELY CONFIRMATION BY THE PLT AFTER THE EVENT. I ATTEMPTED TO CONTACT ACR Y BUT RECEIVED NO RESPONSE. HE WAS ON A HDG NOW THAT WOULD PUT HIM IN CONFLICT WITH ACR X. I COULDN'T BREAK THROUGH THE XMISSION OF ACR X. I ATTEMPTED BROADCASTING ON GUARD FREQ, 121.5, BUT RECEIVED NO RESPONSE. AN ACFT ON ANOTHER FREQ WAS SOLICITED TO BROADCAST ON MY FREQ TO RAISE ACR X, BUT RECEIVED NO RESPONSE. WE NO LONGER HAVE PHONE LINES TO FSS'S, SO WE WERE UNABLE TO HAVE FLT SERVICE BROADCAST ON A VOR FREQ AT COYLE OR KENNEDY. WE WATCHED HELPLESSLY AS THE 2 ACFT CLOSED AT AN ALARMING RATE: ACR Y FLT CROSSED IN FRONT OF THE ACR X FLT AT THE SAME ALT AND 2 MI. BY THIS TIME, ACR Y RETURNED TO PHL APCH AREA FOR INSTRUCTIONS. WE HAD ALERTED PHL APCH AND THEY ASSIGNED ACR Y AN ALTERNATE FREQ. ACR X REALIZED HIS MISTAKE AND CLRED THE STUCK MICROPHONE. HE APOLOGIZED, AND I SAID A FEW THINGS ABOUT FREQ ALERTNESS. I DOUBT THAT ACR X HAD THE FREQ IN A HEADSET WHICH WOULD HAVE ALERTED HIM TO THE PROBLEM. ALSO, I WAS TOLD BY QUALITY ASSURANCE THAT WHEN THIS HAS HAPPENED IN THE PAST, IT WAS SUGGESTED A LIGHT BE FITTED IN THE COCKPIT WHEN THE PLT IS XMITTING. THE AIRLINES, HOWEVER, IGNORE THIS SUGGESTION, STATING COST FACTORS. I FEEL THAT ULTIMATELY, IT WILL TAKE A DISASTER TO CHANGE THEIR MINDS. ONE NEARLY TOOK PLACE HERE.

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.