ZID controller experienced operational error at FL270 during turbulence encounters.

Attributes
ACN	610344
Time
Date	200403
Day	Fri
Local Time Of Day	0601 To 1200
Place
Locale Reference	navaid : hvq.vor
State Reference	WV
Altitude	msl bound lower : 27000 msl bound upper : 28000
Environment
Flight Conditions	IMC
Weather Elements	Turbulence
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zid.artcc
Operator	common carrier : air carrier
Make Model Name	B737-800
Operating Under FAR Part	Part 121
Navigation In Use	other
Flight Phase	cruise : enroute altitude change descent : vacating altitude
Route In Use	enroute airway : j24.airway
Flight Plan	IFR
Aircraft 2
Controlling Facilities	artcc : zid.artcc
Operator	general aviation : corporate
Make Model Name	Learjet 55
Operating Under FAR Part	Part 91
Flight Phase	cruise : level
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	controller : radar
Qualification	controller : radar
Experience	controller radar : 4 controller time certified in position1 : 1 flight time total : 60
ASRS Report	610344
Person 2
Affiliation	government : faa
Function	controller : handoff position
Qualification	controller : radar
Experience	controller radar : 19 controller time certified in position1 : 17.5
ASRS Report	610346
Events
Anomaly	conflict : airborne less severe non adherence : required legal separation
Independent Detector	atc equipment : conflict alert other controllera other controllerb
Resolutory Action	controller : issued new clearance
Consequence	faa : investigated
Miss Distance	horizontal : 18000 vertical : 0
Supplementary
Problem Areas	ATC Human Performance
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

After descending aircraft X, I xferred communication to next sector. Aircraft Y was already xferred to that sector. Aircraft X turned after hvq VOR approximately 70 degree to join J24 and I thought he was still heading sbound. Conflict alert notification triggered and vectors were issued. Separation was lost with approximately 3 mi and 0 vertical. Supplemental information from acn 610346: moderate to severe turbulence FL290 and above caused compression at FL280 and below. Numerous aircraft descending due to turbulence. I was helping radar man coordinate for numerous aircraft descending. We had been extremely busy. Radar man did not observe aircraft #1 changing directions at hvq (approximately 70 degree turn) and descended aircraft #1 into aircraft #2.

Original NASA ASRS Text

Title: ZID CTLR EXPERIENCED OPERROR AT FL270 DURING TURB ENCOUNTERS.

Narrative: AFTER DSNDING ACFT X, I XFERRED COM TO NEXT SECTOR. ACFT Y WAS ALREADY XFERRED TO THAT SECTOR. ACFT X TURNED AFTER HVQ VOR APPROX 70 DEG TO JOIN J24 AND I THOUGHT HE WAS STILL HDG SBOUND. CONFLICT ALERT NOTIFICATION TRIGGERED AND VECTORS WERE ISSUED. SEPARATION WAS LOST WITH APPROX 3 MI AND 0 VERT. SUPPLEMENTAL INFO FROM ACN 610346: MODERATE TO SEVERE TURB FL290 AND ABOVE CAUSED COMPRESSION AT FL280 AND BELOW. NUMEROUS ACFT DSNDING DUE TO TURB. I WAS HELPING RADAR MAN COORDINATE FOR NUMEROUS ACFT DSNDING. WE HAD BEEN EXTREMELY BUSY. RADAR MAN DID NOT OBSERVE ACFT #1 CHANGING DIRECTIONS AT HVQ (APPROX 70 DEG TURN) AND DSNDED ACFT #1 INTO ACFT #2.

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.