Narrative:

Approach control was combined at one position, F1 (position symbol west). Training was in progress at F1. Departure control was combined at one position, krant (position symbol south). I was originally told to decombine the east approach position, F2 (position symbol east), from F1, but due to the light traffic, the instructor and trainee requested the position remained combined. Therefore, I was instructed to relieve the controller at the krant departure position. Aircraft #1, a B757, departed washington sbound on the dca 185 degree radial. I initially cleared aircraft #1 to 6000 ft, the vertical limit of my airspace. As aircraft #1 approached oxxon NDB (5 NM south of dca), I coordinated for further climb. The appropriate sector to coordinate a climb with would normally be F2, but, believing the position to still be combined, I coordinated with F1, saying 'at oxxon direct daily, climbing to 10, (call sign).' F1 responded 'approved.' I was aware aircraft #2, a B757 inbound to bwi, was traffic for aircraft #1, and called the traffic to aircraft #1 as 'a B757, 1 O'clock and 15 mi, nebound, descending to 11000 ft.' I expected F1 to stop aircraft #2 at 11000 ft. Due to WX in the vicinity of ott, aircraft #1 was deviating on a sbound heading during his climb to 10000 ft. Aircraft #2 was tracking nebound towards ott. As aircraft #1 was climbing through 9600 ft, aircraft #2 descended through 11000 ft. At this point, the OJT instructor asked, 'what are you doing with that guy?' I responded, 'climbing to 10000 ft like I coordinated.' the aircraft were approximately 5 mi apart at this time. I immediately told aircraft #1 that the traffic was descending through 11000 ft and to climb and maintain FL190. At this point I turned around to look at the F1 position and discovered that F2 had been opened without my knowledge. F2 turned aircraft #2 eastbound, and aircraft #1 passed behind aircraft #2. I would estimate the closest point of approach to be less than 1 mi and less than 300 ft. In his investigation of the incident, the supervisor determined go-behind separation had been established by F2 turning aircraft #2 eastbound, with aircraft #1 heading sbound. Aircraft #1 asked me if I had been talking to the other aircraft and where he came from. I explained that the other aircraft was on another frequency, that there had been a miscom between ATC, and that the aircraft had been descended below 11000 ft. Aircraft #1 advised that he had received a TCASII RA to climb and that the other aircraft was 'right there.' what happened? There were basically 3 mistakes made here. First, the instructor and trainee failed to notify me they were opening the F2 position. Secondly, F1 incorrectly approved a point on aircraft #1 climbing sbound from oxxon, into airspace belonging to F2. Finally, I failed to realize from the position symbol east displayed on the scope that F2 had been opened. I believe this situation would have been avoided if any of the following had occurred: F2 advises krant it is open, F1 does not approve the point and instead tells krant F2 is open, krant recognizes from the radar display that F2 is open. It also should be stated that this occurred at the beginning of the day shift, on our first day back to work, after a beautiful WX weekend. It is possible that the level of alertness displayed by all controllers involved was less than normal. I know that I was certainly not 100 percent at the time of the incident. I did not feel I had gotten a good night's sleep the night before. I did not, however, realize the impact it had on my awareness of surrounding activities. I did not hear the F2 position controllers move to the F2 position, nor did I recognize the voice of F1 as someone other than the trainee I thought was working F1. I believe these human performance factors played a role in this incident.

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Original NASA ASRS Text

Title: B757 TCASII RA CLB HAD LTSS FROM DSNDING B757. SYS ERROR.

Narrative: APCH CTL WAS COMBINED AT ONE POS, F1 (POS SYMBOL W). TRAINING WAS IN PROGRESS AT F1. DEP CTL WAS COMBINED AT ONE POS, KRANT (POS SYMBOL S). I WAS ORIGINALLY TOLD TO DECOMBINE THE E APCH POS, F2 (POS SYMBOL E), FROM F1, BUT DUE TO THE LIGHT TFC, THE INSTRUCTOR AND TRAINEE REQUESTED THE POS REMAINED COMBINED. THEREFORE, I WAS INSTRUCTED TO RELIEVE THE CTLR AT THE KRANT DEP POS. ACFT #1, A B757, DEPARTED WASHINGTON SBOUND ON THE DCA 185 DEG RADIAL. I INITIALLY CLRED ACFT #1 TO 6000 FT, THE VERT LIMIT OF MY AIRSPACE. AS ACFT #1 APCHED OXXON NDB (5 NM S OF DCA), I COORDINATED FOR FURTHER CLB. THE APPROPRIATE SECTOR TO COORDINATE A CLB WITH WOULD NORMALLY BE F2, BUT, BELIEVING THE POS TO STILL BE COMBINED, I COORDINATED WITH F1, SAYING 'AT OXXON DIRECT DAILY, CLBING TO 10, (CALL SIGN).' F1 RESPONDED 'APPROVED.' I WAS AWARE ACFT #2, A B757 INBOUND TO BWI, WAS TFC FOR ACFT #1, AND CALLED THE TFC TO ACFT #1 AS 'A B757, 1 O'CLOCK AND 15 MI, NEBOUND, DSNDING TO 11000 FT.' I EXPECTED F1 TO STOP ACFT #2 AT 11000 FT. DUE TO WX IN THE VICINITY OF OTT, ACFT #1 WAS DEVIATING ON A SBOUND HDG DURING HIS CLB TO 10000 FT. ACFT #2 WAS TRACKING NEBOUND TOWARDS OTT. AS ACFT #1 WAS CLBING THROUGH 9600 FT, ACFT #2 DSNDED THROUGH 11000 FT. AT THIS POINT, THE OJT INSTRUCTOR ASKED, 'WHAT ARE YOU DOING WITH THAT GUY?' I RESPONDED, 'CLBING TO 10000 FT LIKE I COORDINATED.' THE ACFT WERE APPROX 5 MI APART AT THIS TIME. I IMMEDIATELY TOLD ACFT #1 THAT THE TFC WAS DSNDING THROUGH 11000 FT AND TO CLB AND MAINTAIN FL190. AT THIS POINT I TURNED AROUND TO LOOK AT THE F1 POS AND DISCOVERED THAT F2 HAD BEEN OPENED WITHOUT MY KNOWLEDGE. F2 TURNED ACFT #2 EBOUND, AND ACFT #1 PASSED BEHIND ACFT #2. I WOULD ESTIMATE THE CLOSEST POINT OF APCH TO BE LESS THAN 1 MI AND LESS THAN 300 FT. IN HIS INVESTIGATION OF THE INCIDENT, THE SUPVR DETERMINED GO-BEHIND SEPARATION HAD BEEN ESTABLISHED BY F2 TURNING ACFT #2 EBOUND, WITH ACFT #1 HDG SBOUND. ACFT #1 ASKED ME IF I HAD BEEN TALKING TO THE OTHER ACFT AND WHERE HE CAME FROM. I EXPLAINED THAT THE OTHER ACFT WAS ON ANOTHER FREQ, THAT THERE HAD BEEN A MISCOM BTWN ATC, AND THAT THE ACFT HAD BEEN DSNDED BELOW 11000 FT. ACFT #1 ADVISED THAT HE HAD RECEIVED A TCASII RA TO CLB AND THAT THE OTHER ACFT WAS 'RIGHT THERE.' WHAT HAPPENED? THERE WERE BASICALLY 3 MISTAKES MADE HERE. FIRST, THE INSTRUCTOR AND TRAINEE FAILED TO NOTIFY ME THEY WERE OPENING THE F2 POS. SECONDLY, F1 INCORRECTLY APPROVED A POINT ON ACFT #1 CLBING SBOUND FROM OXXON, INTO AIRSPACE BELONGING TO F2. FINALLY, I FAILED TO REALIZE FROM THE POS SYMBOL E DISPLAYED ON THE SCOPE THAT F2 HAD BEEN OPENED. I BELIEVE THIS SIT WOULD HAVE BEEN AVOIDED IF ANY OF THE FOLLOWING HAD OCCURRED: F2 ADVISES KRANT IT IS OPEN, F1 DOES NOT APPROVE THE POINT AND INSTEAD TELLS KRANT F2 IS OPEN, KRANT RECOGNIZES FROM THE RADAR DISPLAY THAT F2 IS OPEN. IT ALSO SHOULD BE STATED THAT THIS OCCURRED AT THE BEGINNING OF THE DAY SHIFT, ON OUR FIRST DAY BACK TO WORK, AFTER A BEAUTIFUL WX WEEKEND. IT IS POSSIBLE THAT THE LEVEL OF ALERTNESS DISPLAYED BY ALL CTLRS INVOLVED WAS LESS THAN NORMAL. I KNOW THAT I WAS CERTAINLY NOT 100 PERCENT AT THE TIME OF THE INCIDENT. I DID NOT FEEL I HAD GOTTEN A GOOD NIGHT'S SLEEP THE NIGHT BEFORE. I DID NOT, HOWEVER, REALIZE THE IMPACT IT HAD ON MY AWARENESS OF SURROUNDING ACTIVITIES. I DID NOT HEAR THE F2 POS CTLRS MOVE TO THE F2 POS, NOR DID I RECOGNIZE THE VOICE OF F1 AS SOMEONE OTHER THAN THE TRAINEE I THOUGHT WAS WORKING F1. I BELIEVE THESE HUMAN PERFORMANCE FACTORS PLAYED A ROLE IN THIS INCIDENT.

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.