Narrative:

At approximately XA10 local time I was working the R75 sector. Traffic volume was slowing diminishing to moderate from very heavy. The R57 sector called me and requested higher on aircraft #1; who they had turned 15 degrees right for the climb. I approved FL270. At that time; another controller plugged into R75 to relieve me. I began a recorded position relief briefing. About halfway through the briefing aircraft #1 checked onto my frequency climbing to FL270 still on a heading. I told the aircraft to fly heading 355 degrees; climb and maintain FL330. Apparently the pilot read back the correct heading; but stated FL390 instead of FL330. I did not catch this mistake; nor did the relieving controller. I finished the briefing and left the sector. A few mins later aircraft #1 climbed through FL330 and reported that they were responding to a TCAS RA and were descending back down to FL330. The controller stated that they were assigned FL330 and to maintain FL330. Aircraft #2 was opposite direction at FL340 and climbed in response to TCAS RA when aircraft #1 left FL330. 1000 ft of vertical separation was maintained. Separation was never lost. Contributing factor was that I was conducting briefing at the time and that the pilot who read back FL390 had a strong accent (foreign air carrier). Supplemental information from acn 731575: 1) I was flying over georgia speaking to ZJX. My first officer was on the other radio talking to flight watch. My flight level was 36000 ft. ZJX asked me if I could accept FL380 for traffic. I looked at my weight on the FMS and said yes; but it would be a slow climb. He said I would have to turn 30 degrees for a vector. I said I could do 500 FPM instead of a vector. He said ok (maybe yes) or words to that effect. So I started to climb to FL380. At about 36300-36400 I got a yellow traffic warning on TCAS at about 10 mi to my left (11 O'clock position). I was heading south from ugn-O7FA. 2) other aircraft told ATC he was getting a warning. He turned 30 degrees and ATC told me to turn 30 degrees right; to which I responded and was told to go back down to FL360. He may have asked my altitude before that I am not sure. The other aircraft later asked ZJX for a phone number. 3) I believed at the time I was cleared to FL380 when I said I could climb at 500 FPM would that be ok and the controller said yes. 4) I thought that there was traffic at my altitude and the controller wanted me higher or deviating to avoid a conflict.

Related reports:

Google
 

Original NASA ASRS Text

Title: ZJX CTLR EXPERIENCED OPERROR AT APPROX FL330 WHEN INCORRECT ASSIGNED ALT READ BACK WAS INCORRECT AND MISSED DURING RELIEF BRIEFING.

Narrative: AT APPROX XA10 LCL TIME I WAS WORKING THE R75 SECTOR. TFC VOLUME WAS SLOWING DIMINISHING TO MODERATE FROM VERY HVY. THE R57 SECTOR CALLED ME AND REQUESTED HIGHER ON ACFT #1; WHO THEY HAD TURNED 15 DEGS R FOR THE CLB. I APPROVED FL270. AT THAT TIME; ANOTHER CTLR PLUGGED INTO R75 TO RELIEVE ME. I BEGAN A RECORDED POS RELIEF BRIEFING. ABOUT HALFWAY THROUGH THE BRIEFING ACFT #1 CHKED ONTO MY FREQ CLBING TO FL270 STILL ON A HDG. I TOLD THE ACFT TO FLY HDG 355 DEGS; CLB AND MAINTAIN FL330. APPARENTLY THE PLT READ BACK THE CORRECT HDG; BUT STATED FL390 INSTEAD OF FL330. I DID NOT CATCH THIS MISTAKE; NOR DID THE RELIEVING CTLR. I FINISHED THE BRIEFING AND LEFT THE SECTOR. A FEW MINS LATER ACFT #1 CLBED THROUGH FL330 AND RPTED THAT THEY WERE RESPONDING TO A TCAS RA AND WERE DSNDING BACK DOWN TO FL330. THE CTLR STATED THAT THEY WERE ASSIGNED FL330 AND TO MAINTAIN FL330. ACFT #2 WAS OPPOSITE DIRECTION AT FL340 AND CLBED IN RESPONSE TO TCAS RA WHEN ACFT #1 LEFT FL330. 1000 FT OF VERT SEPARATION WAS MAINTAINED. SEPARATION WAS NEVER LOST. CONTRIBUTING FACTOR WAS THAT I WAS CONDUCTING BRIEFING AT THE TIME AND THAT THE PLT WHO READ BACK FL390 HAD A STRONG ACCENT (FOREIGN ACR). SUPPLEMENTAL INFO FROM ACN 731575: 1) I WAS FLYING OVER GEORGIA SPEAKING TO ZJX. MY FO WAS ON THE OTHER RADIO TALKING TO FLT WATCH. MY FLT LEVEL WAS 36000 FT. ZJX ASKED ME IF I COULD ACCEPT FL380 FOR TFC. I LOOKED AT MY WT ON THE FMS AND SAID YES; BUT IT WOULD BE A SLOW CLB. HE SAID I WOULD HAVE TO TURN 30 DEGS FOR A VECTOR. I SAID I COULD DO 500 FPM INSTEAD OF A VECTOR. HE SAID OK (MAYBE YES) OR WORDS TO THAT EFFECT. SO I STARTED TO CLB TO FL380. AT ABOUT 36300-36400 I GOT A YELLOW TFC WARNING ON TCAS AT ABOUT 10 MI TO MY L (11 O'CLOCK POS). I WAS HDG S FROM UGN-O7FA. 2) OTHER ACFT TOLD ATC HE WAS GETTING A WARNING. HE TURNED 30 DEGS AND ATC TOLD ME TO TURN 30 DEGS R; TO WHICH I RESPONDED AND WAS TOLD TO GO BACK DOWN TO FL360. HE MAY HAVE ASKED MY ALT BEFORE THAT I AM NOT SURE. THE OTHER ACFT LATER ASKED ZJX FOR A PHONE NUMBER. 3) I BELIEVED AT THE TIME I WAS CLRED TO FL380 WHEN I SAID I COULD CLB AT 500 FPM WOULD THAT BE OK AND THE CTLR SAID YES. 4) I THOUGHT THAT THERE WAS TFC AT MY ALT AND THE CTLR WANTED ME HIGHER OR DEVIATING TO AVOID A CONFLICT.

Data retrieved from NASA's ASRS site as of January 2009 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.