Narrative:

While working radar clearance delivery, I issued a clearance to aircraft (a PA24) at north central state airport (sfz) in rhode island. When aircraft called ready for departure, there was already an IFR aircraft released ahead of him. I advised aircraft X to 'hold for release and stand by.' I believed at the time that he had read back 'hold for release and standing by.' I later learned by listening to the audio tape that he had read back 'released and standing by.' after this transmission, I walked to the radar controller responsible for releasing this aircraft. I told him that aircraft X was ready and to let me know when I could release him. Approximately 1 min later, aircraft X called and asked me to verify that he was released. I advised the pilot 'negative, there is another departure in front of you that we need to identify and get out of your way.' he acknowledged by stating 'oh yeah, we saw the aircraft going to departure.' I heard something about 'going to departure,' so I asked the pilot to say again. He responded by stating 'that's ok, we're released and we'll call you in the air.' I immediately responded by stating 'negative, hold for release, remain on the ground.' the pilot of aircraft X responded with 'ok.' the aircraft was then observed airborne and flying in a traffic pattern orbit apparently returning to the airport. It was determined that when aircraft X became airborne that 1.15 mi lateral and 800 ft vertical separation existed resulting in an operational error. While I believe that ambient noise and the layout of the control room played a role in hearing the readback incorrectly, the fact is, that it was my responsibility to ensure its accuracy. I believed that there was no question the aircraft would remain on the ground.

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Original NASA ASRS Text

Title: A CLRNC DELIVERY CTLR AT PVD MISHEARS A PLT'S READBACK TO HOLD FOR RELEASE AND LATER LEARNS THE PLT RESPONDED BY STATING 'RELEASED AND STANDING BY.'

Narrative: WHILE WORKING RADAR CLRNC DELIVERY, I ISSUED A CLRNC TO ACFT (A PA24) AT NORTH CENTRAL STATE ARPT (SFZ) IN RHODE ISLAND. WHEN ACFT CALLED READY FOR DEP, THERE WAS ALREADY AN IFR ACFT RELEASED AHEAD OF HIM. I ADVISED ACFT X TO 'HOLD FOR RELEASE AND STAND BY.' I BELIEVED AT THE TIME THAT HE HAD READ BACK 'HOLD FOR RELEASE AND STANDING BY.' I LATER LEARNED BY LISTENING TO THE AUDIO TAPE THAT HE HAD READ BACK 'RELEASED AND STANDING BY.' AFTER THIS XMISSION, I WALKED TO THE RADAR CTLR RESPONSIBLE FOR RELEASING THIS ACFT. I TOLD HIM THAT ACFT X WAS READY AND TO LET ME KNOW WHEN I COULD RELEASE HIM. APPROX 1 MIN LATER, ACFT X CALLED AND ASKED ME TO VERIFY THAT HE WAS RELEASED. I ADVISED THE PLT 'NEGATIVE, THERE IS ANOTHER DEP IN FRONT OF YOU THAT WE NEED TO IDENT AND GET OUT OF YOUR WAY.' HE ACKNOWLEDGED BY STATING 'OH YEAH, WE SAW THE ACFT GOING TO DEP.' I HEARD SOMETHING ABOUT 'GOING TO DEP,' SO I ASKED THE PLT TO SAY AGAIN. HE RESPONDED BY STATING 'THAT'S OK, WE'RE RELEASED AND WE'LL CALL YOU IN THE AIR.' I IMMEDIATELY RESPONDED BY STATING 'NEGATIVE, HOLD FOR RELEASE, REMAIN ON THE GND.' THE PLT OF ACFT X RESPONDED WITH 'OK.' THE ACFT WAS THEN OBSERVED AIRBORNE AND FLYING IN A TFC PATTERN ORBIT APPARENTLY RETURNING TO THE ARPT. IT WAS DETERMINED THAT WHEN ACFT X BECAME AIRBORNE THAT 1.15 MI LATERAL AND 800 FT VERT SEPARATION EXISTED RESULTING IN AN OPERROR. WHILE I BELIEVE THAT AMBIENT NOISE AND THE LAYOUT OF THE CTL ROOM PLAYED A ROLE IN HEARING THE READBACK INCORRECTLY, THE FACT IS, THAT IT WAS MY RESPONSIBILITY TO ENSURE ITS ACCURACY. I BELIEVED THAT THERE WAS NO QUESTION THE ACFT WOULD REMAIN ON THE GND.

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.