Air carrier X possible less than standard separation from air carrier Y. Possible system error.

Attributes
ACN	151363
Time
Date	199007
Day	Sat
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : iad
State Reference	DC
Altitude	msl bound lower : 2500 msl bound upper : 8000
Environment
Flight Conditions	Mixed
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : iad
Operator	common carrier : air carrier
Make Model Name	Large Transport
Navigation In Use	Other
Flight Phase	climbout : intermediate altitude descent other
Route In Use	enroute : on vectors
Flight Plan	IFR
Aircraft 2
Operator	common carrier : air carrier
Make Model Name	Large Transport
Flight Phase	cruise other
Route In Use	enroute : on vectors
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 210 flight time total : 19000 flight time type : 210
ASRS Report	151363
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Experience	flight time last 90 days : 200 flight time total : 10500 flight time type : 3000
ASRS Report	151364
Events
Anomaly	conflict : airborne less severe inflight encounter : weather
Independent Detector	other controllera
Resolutory Action	controller : issued new clearance other
Consequence	Other
Miss Distance	horizontal : 18000 vertical : 500
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	other

Narrative:

Air carrier X on climb out from iad (dulles). We were heading 270 degree. Departure cleared us to 'turn left to 240 degree, climb to 10000'.' at 7700', departure said 'cancel your clearance, level off at 7000'.' I asked if he wanted us to land to 7000' and he responded 'yes, you have air carrier Y at 10 O'clock 8000'.' I observed a large transport at 10 O'clock 3-4 NM.

Original NASA ASRS Text

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

Narrative: ACR X ON CLBOUT FROM IAD (DULLES). WE WERE HDG 270 DEG. DEP CLRED US TO 'TURN L TO 240 DEG, CLB TO 10000'.' AT 7700', DEP SAID 'CANCEL YOUR CLRNC, LEVEL OFF AT 7000'.' I ASKED IF HE WANTED US TO LAND TO 7000' AND HE RESPONDED 'YES, YOU HAVE ACR Y AT 10 O'CLOCK 8000'.' I OBSERVED A LARGE TRANSPORT AT 10 O'CLOCK 3-4 NM.

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.