ZOB ARTCC radar controller misjudged closure rate of converging traffic resulting in a loss of separ...

Attributes
ACN	549638
Time
Date	200206
Day	Wed
Local Time Of Day	1201 To 1800
Place
Locale Reference	navaid : jst.vortac
State Reference	PA
Altitude	msl single value : 21000
Environment
Flight Conditions	IMC
Weather Elements	Thunderstorm
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zob.artcc
Operator	common carrier : air carrier
Make Model Name	B737 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	descent : intermediate altitude descent : vacating altitude
Flight Plan	IFR
Aircraft 2
Controlling Facilities	artcc : zob.artcc
Operator	common carrier : air carrier
Make Model Name	Beech 1900
Operating Under FAR Part	Part 135
Flight Phase	cruise : level
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	controller : radar
Qualification	controller : developmental
Experience	controller limited radar : 1 controller time certified in position1 : 1 flight time total : 50
ASRS Report	549638
Person 2
Affiliation	government : faa
Function	controller : handoff position
Events
Anomaly	conflict : airborne critical inflight encounter : weather non adherence : published procedure non adherence : required legal separation
Independent Detector	atc equipment : conflict alert atc equipment other atc equipment : radar aircraft equipment : tcas other controllera
Resolutory Action	flight crew : took evasive action
Consequence	faa : investigated
Miss Distance	horizontal : 20400 vertical : 200
Supplementary
Problem Areas	Flight Crew Human Performance ATC Human Performance
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

Thunderstorms were developing and building in and around airspace. Many aircraft were deviating and causing excess coordination. The B190 was sbound at FL210, and the B737 was direct to pit at FL220. The B737 was given descent to 16000 ft and the conflicting B190 was overlooked. When conflict alert activated the aircraft were approximately 5 mi apart. The B737 was turned 30 degrees left and the B190 was turned 45 degrees right. Separation was lost before the turns could take effect. The radar associate assigned to the position was busy coordinating and fixing flight plans in the host system. The B737 responded to an RA and climbed, and both aircraft reported visual contact of traffic. The situation occurred due to an oversight of traffic during a complex situation of deviating aircraft.

Original NASA ASRS Text

Title: ZOB ARTCC RADAR CTLR MISJUDGED CLOSURE RATE OF CONVERGING TFC RESULTING IN A LOSS OF SEPARATION.

Narrative: TSTMS WERE DEVELOPING AND BUILDING IN AND AROUND AIRSPACE. MANY ACFT WERE DEVIATING AND CAUSING EXCESS COORD. THE B190 WAS SBOUND AT FL210, AND THE B737 WAS DIRECT TO PIT AT FL220. THE B737 WAS GIVEN DSCNT TO 16000 FT AND THE CONFLICTING B190 WAS OVERLOOKED. WHEN CONFLICT ALERT ACTIVATED THE ACFT WERE APPROX 5 MI APART. THE B737 WAS TURNED 30 DEGS L AND THE B190 WAS TURNED 45 DEGS R. SEPARATION WAS LOST BEFORE THE TURNS COULD TAKE EFFECT. THE RADAR ASSOCIATE ASSIGNED TO THE POS WAS BUSY COORDINATING AND FIXING FLT PLANS IN THE HOST SYS. THE B737 RESPONDED TO AN RA AND CLBED, AND BOTH ACFT RPTED VISUAL CONTACT OF TFC. THE SIT OCCURRED DUE TO AN OVERSIGHT OF TFC DURING A COMPLEX SIT OF DEVIATING ACFT.

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.

ZOB ARTCC radar controller misjudged closure rate of converging traffic resulting in a loss of separation.