FK10 and CL65 had near midair collision in ZDC class a airspace.

Attributes
ACN	418380
Time
Date	199810
Day	Tue
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : lyh
State Reference	VA
Altitude	msl bound lower : 19600 msl bound upper : 20000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zdc
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Navigation In Use	Other Other
Flight Phase	cruise other
Route In Use	enroute : direct
Flight Plan	IFR
Aircraft 2
Operator	common carrier : air carrier
Make Model Name	Medium Transport, Low Wing, 2 Turbojet Eng
Navigation In Use	Other Other
Flight Phase	cruise other descent other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 142 flight time total : 17000 flight time type : 4600
ASRS Report	418380
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument
Events
Anomaly	conflict : nmac non adherence : required legal separation non adherence : published procedure
Independent Detector	aircraft equipment other aircraft equipment : unspecified other flight crewa
Resolutory Action	flight crew : took evasive action other
Consequence	Other
Miss Distance	horizontal : 18000 vertical : 400
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

Route was lyh direct gso, level at FL200. Approximately 30 NM southwest of lyh, we received TCASII traffic alert followed immediately by an RA to descend. The first officer disconnected the autoplt and executed the maneuver, descending to about FL196. When TCASII reported clear of traffic, we advised ATC and returned to FL200. Traffic was visually acquired during the maneuver, crossing in front of us right to left at about 3 NM, 500 ft above us. When advised of our action, ZDC ordered a turn to 270 degrees. Our original heading had been about 220 degrees. We immediately initiated the turn but ATC seemed to be having radio difficulty in that ZDC was not seeming to hear our acknowledgement of 270 degree heading. ATC soon thereafter cleared us direct gso. Supplemental information from acn 418077: aircraft descending from FL210 to 17000 ft was inadvertently descended through an aircraft at FL200.

Original NASA ASRS Text

Title: FK10 AND CL65 HAD NMAC IN ZDC CLASS A AIRSPACE.

Narrative: RTE WAS LYH DIRECT GSO, LEVEL AT FL200. APPROX 30 NM SW OF LYH, WE RECEIVED TCASII TFC ALERT FOLLOWED IMMEDIATELY BY AN RA TO DSND. THE FO DISCONNECTED THE AUTOPLT AND EXECUTED THE MANEUVER, DSNDING TO ABOUT FL196. WHEN TCASII RPTED CLR OF TFC, WE ADVISED ATC AND RETURNED TO FL200. TFC WAS VISUALLY ACQUIRED DURING THE MANEUVER, XING IN FRONT OF US R TO L AT ABOUT 3 NM, 500 FT ABOVE US. WHEN ADVISED OF OUR ACTION, ZDC ORDERED A TURN TO 270 DEGS. OUR ORIGINAL HDG HAD BEEN ABOUT 220 DEGS. WE IMMEDIATELY INITIATED THE TURN BUT ATC SEEMED TO BE HAVING RADIO DIFFICULTY IN THAT ZDC WAS NOT SEEMING TO HEAR OUR ACKNOWLEDGEMENT OF 270 DEG HDG. ATC SOON THEREAFTER CLRED US DIRECT GSO. SUPPLEMENTAL INFO FROM ACN 418077: ACFT DSNDING FROM FL210 TO 17000 FT WAS INADVERTENTLY DSNDED THROUGH AN ACFT AT FL200.

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.