ZOB radar controller did not notice very slow descent of MD80 resulting in a conflict with a B757.

Attributes
ACN	553981
Time
Date	200207
Day	Sun
Local Time Of Day	0601 To 1200
Place
Locale Reference	navaid : fnt.vortac
State Reference	MI
Altitude	msl bound lower : 29400 msl bound upper : 31000
Environment
Flight Conditions	VMC
Weather Elements	Turbulence
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zob.artcc
Operator	common carrier : air carrier
Make Model Name	MD-80 Series (DC-9-80) Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	descent : intermediate altitude
Flight Plan	IFR
Aircraft 2
Controlling Facilities	artcc : zob.artcc
Operator	common carrier : air carrier
Make Model Name	B757 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Navigation In Use	other
Flight Phase	cruise : level
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	controller : supervisor oversight : supervisor
Qualification	controller : radar
Experience	controller military : 4 controller radar : 21 controller supervisory : 10 controller time certified in position1 : 19
ASRS Report	553981
Person 2
Affiliation	government : faa
Function	controller : radar
Qualification	controller : radar
Experience	controller military : 4 controller radar : 6 controller time certified in position2 : 3
ASRS Report	553764
Events
Anomaly	conflict : airborne less severe non adherence : published procedure non adherence : required legal separation
Independent Detector	atc equipment other atc equipment : radar/mode c other controllera other controllerb other flight crewa other flight crewb
Resolutory Action	other
Consequence	faa : investigated
Miss Distance	horizontal : 27000 vertical : 1800
Supplementary
Problem Areas	Flight Crew Human Performance ATC Human Performance
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

Aircraft X, MD80, inbound to ord was on a vector descending to FL280 to get below aircraft Y (B757) at FL310 traveling to sjc. Moderate to heavy traffic volume prevented the controllers from monitoring the descent rate of aircraft X. Separation was lost at 4.8 mi and 1600 ft. The descent rate ended up being slower than expected. Callback conversation with reporter revealed the following information: controller reporter stated he had only been checked out on the sector for about 3 months. He said when the incident occurred he had been focused on traffic at the top end of the cope to insure they were leaving the sector at the proper altitudes. He said traffic became busy because of pilots' requests for altitudes with better rides. The super high sector was combined to his sector, but did not have significant amount of traffic. A radar associate was plugged in providing assistance. During training, his instructor advised him to scan traffic often and not focus on just 1 area of the sector. Lesson learned.

Original NASA ASRS Text

Title: ZOB RADAR CTLR DID NOT NOTICE VERY SLOW DSCNT OF MD80 RESULTING IN A CONFLICT WITH A B757.

Narrative: ACFT X, MD80, INBOUND TO ORD WAS ON A VECTOR DSNDING TO FL280 TO GET BELOW ACFT Y (B757) AT FL310 TRAVELING TO SJC. MODERATE TO HVY TFC VOLUME PREVENTED THE CTLRS FROM MONITORING THE DSCNT RATE OF ACFT X. SEPARATION WAS LOST AT 4.8 MI AND 1600 FT. THE DSCNT RATE ENDED UP BEING SLOWER THAN EXPECTED. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: CTLR RPTR STATED HE HAD ONLY BEEN CHKED OUT ON THE SECTOR FOR ABOUT 3 MONTHS. HE SAID WHEN THE INCIDENT OCCURRED HE HAD BEEN FOCUSED ON TFC AT THE TOP END OF THE COPE TO INSURE THEY WERE LEAVING THE SECTOR AT THE PROPER ALTS. HE SAID TFC BECAME BUSY BECAUSE OF PLTS' REQUESTS FOR ALTS WITH BETTER RIDES. THE SUPER HIGH SECTOR WAS COMBINED TO HIS SECTOR, BUT DID NOT HAVE SIGNIFICANT AMOUNT OF TFC. A RADAR ASSOCIATE WAS PLUGGED IN PROVIDING ASSISTANCE. DURING TRAINING, HIS INSTRUCTOR ADVISED HIM TO SCAN TFC OFTEN AND NOT FOCUS ON JUST 1 AREA OF THE SECTOR. LESSON LEARNED.

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.