Air carrier X had less than standard separation from air carrier Y. System error.

Attributes
ACN	161915
Time
Date	199011
Day	Thu
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : lvl
State Reference	VA
Altitude	msl bound lower : 26700 msl bound upper : 27000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zdc tower : cun
Operator	common carrier : air carrier
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Flight Phase	cruise other
Route In Use	enroute : on vectors
Flight Plan	IFR
Aircraft 2
Operator	common carrier : air carrier
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Flight Phase	descent other
Route In Use	enroute : direct
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	controller : radar
Qualification	controller : radar
Experience	controller radar : 5
ASRS Report	161915
Person 2
Affiliation	government : faa
Function	controller : radar
Qualification	controller : radar
Events
Anomaly	conflict : airborne less severe non adherence : required legal separation non adherence : published procedure
Independent Detector	other controllera
Resolutory Action	other
Consequence	faa : investigated
Miss Distance	horizontal : 13800 vertical : 700
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	Intra Facility Coordination Failure Operational Error

Narrative:

I was working the radar position at blackstone intermediate sector. I was working it alone. I had no d-side. At the time I was sequencing iad arrs and climbing departure aircraft through them. The gordonsville high sector (sector 32) called me to take a handoff on air carrier X at the time. Air carrier X was about 10 mi off his route of flight and diverging from it by some 20 degrees. I asked the controller what air carrier X was doing to which he responded that the aircraft was heading 85 degrees to get around other traffic. I thought the aircraft was climbing to FL250. However, the aircraft was cleared up to FL260, wrong altitude for direction of flight, west/O proper coordination with me. Within a couple of mins I cleared air carrier Y to descend to FL260 from FL270, just in front of air carrier X. Sep was immediately lost and went as low as 2.3 mi and 700'. I called traffic to both aircraft and the air carrier Y advised having air carrier X in sight. No evasive action was necessary. The main causal factor to this occurrence is that I apparently had a mental block about air carrier X altitude--I thought he was only climbing to FL250, thus FL260 was available, so I used it. I think a major contributing factor to it though is that the gordonsville high controller did not coordinated verbally as required the issuance of a wrong altitude for direction of flight. If he had, I don't think that I would have made the error.

Original NASA ASRS Text

Title: ACR X HAD LESS THAN STANDARD SEPARATION FROM ACR Y. SYSTEM ERROR.

Narrative: I WAS WORKING THE RADAR POS AT BLACKSTONE INTERMEDIATE SECTOR. I WAS WORKING IT ALONE. I HAD NO D-SIDE. AT THE TIME I WAS SEQUENCING IAD ARRS AND CLBING DEP ACFT THROUGH THEM. THE GORDONSVILLE HIGH SECTOR (SECTOR 32) CALLED ME TO TAKE A HDOF ON ACR X AT THE TIME. ACR X WAS ABOUT 10 MI OFF HIS RTE OF FLT AND DIVERGING FROM IT BY SOME 20 DEGS. I ASKED THE CTLR WHAT ACR X WAS DOING TO WHICH HE RESPONDED THAT THE ACFT WAS HDG 85 DEGS TO GET AROUND OTHER TFC. I THOUGHT THE ACFT WAS CLBING TO FL250. HOWEVER, THE ACFT WAS CLRED UP TO FL260, WRONG ALT FOR DIRECTION OF FLT, W/O PROPER COORD WITH ME. WITHIN A COUPLE OF MINS I CLRED ACR Y TO DSND TO FL260 FROM FL270, JUST IN FRONT OF ACR X. SEP WAS IMMEDIATELY LOST AND WENT AS LOW AS 2.3 MI AND 700'. I CALLED TFC TO BOTH ACFT AND THE ACR Y ADVISED HAVING ACR X IN SIGHT. NO EVASIVE ACTION WAS NECESSARY. THE MAIN CAUSAL FACTOR TO THIS OCCURRENCE IS THAT I APPARENTLY HAD A MENTAL BLOCK ABOUT ACR X ALT--I THOUGHT HE WAS ONLY CLBING TO FL250, THUS FL260 WAS AVAILABLE, SO I USED IT. I THINK A MAJOR CONTRIBUTING FACTOR TO IT THOUGH IS THAT THE GORDONSVILLE HIGH CTLR DID NOT COORDINATED VERBALLY AS REQUIRED THE ISSUANCE OF A WRONG ALT FOR DIRECTION OF FLT. IF HE HAD, I DON'T THINK THAT I WOULD HAVE MADE THE ERROR.

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.