Less than standard separation between 2 air carrier aircraft. Operational error.

Attributes
ACN	133478
Time
Date	199001
Day	Sun
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : crg
State Reference	FL
Altitude	msl bound lower : 29000 msl bound upper : 29000
Environment
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zjx
Operator	common carrier : air carrier
Make Model Name	Large Transport, Low Wing, 3 Turbojet Eng
Flight Phase	cruise other descent other
Route In Use	enroute : on vectors
Flight Plan	IFR
Aircraft 2
Operator	common carrier : air carrier
Make Model Name	Large Transport, Low Wing, 2 Turbojet Eng
Navigation In Use	Other Other
Flight Phase	cruise other
Route In Use	enroute : on vectors
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	controller : radar
Qualification	controller : radar
Experience	controller radar : 19
ASRS Report	133478
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	conflict : airborne less severe non adherence : required legal separation
Independent Detector	other other : unspecified atc
Resolutory Action	controller : issued new clearance none taken : unable
Consequence	faa : investigated
Miss Distance	horizontal : 27600 vertical : 0
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

2 aircraft at FL310 crossing. I descended air carrier X to FL290 to miss Z at FL310, and I turned air carrier Y at FL290 to a heading of 010 degree to miss air carrier X. I turned air carrier X to a heading of 180 degree. Both aircraft I had to transmit twice for a reply. Second transmission to Y, I turned to a heading of 020 degree and separation was apparently lost. I think if both aircraft replied with first transmission separation would not have been lost.

Original NASA ASRS Text

Title: LESS THAN STANDARD SEPARATION BETWEEN 2 ACR ACFT. OPERATIONAL ERROR.

Narrative: 2 ACFT AT FL310 XING. I DESCENDED ACR X TO FL290 TO MISS Z AT FL310, AND I TURNED ACR Y AT FL290 TO A HDG OF 010 DEG TO MISS ACR X. I TURNED ACR X TO A HDG OF 180 DEG. BOTH ACFT I HAD TO XMIT TWICE FOR A REPLY. SECOND XMISSION TO Y, I TURNED TO A HDG OF 020 DEG AND SEPARATION WAS APPARENTLY LOST. I THINK IF BOTH ACFT REPLIED WITH FIRST XMISSION SEPARATION WOULD NOT HAVE BEEN LOST.

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.