Radar separation was lost between a descending aircraft and an aircraft level at FL330.

Attributes
ACN	154319
Time
Date	199008
Day	Sat
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : rst
State Reference	MN
Altitude	msl bound lower : 33000 msl bound upper : 33000
Environment
Flight Conditions	Mixed
Light	Dusk
Aircraft 1
Controlling Facilities	artcc : zmp
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Navigation In Use	Other
Flight Phase	cruise other
Flight Plan	IFR
Aircraft 2
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Flight Phase	descent other
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	controller : non radar
Qualification	controller : radar
Experience	controller non radar : 2 controller radar : 1
ASRS Report	154319
Person 2
Affiliation	government : faa
Function	controller : radar
Qualification	controller : radar
Experience	controller radar : 2
ASRS Report	154862
Events
Anomaly	conflict : airborne less severe non adherence : required legal separation non adherence : published procedure
Independent Detector	atc equipment other atc equipment : unspecified
Resolutory Action	controller : issued new clearance other
Consequence	faa : investigated
Miss Distance	horizontal : 18000 vertical : 800
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

A large amount of WX and thunderstorms were in or near the sector. Most or all aircraft were deviating. An medium large transport X was an overflt from sea to dtw at FL330. He was deviating for the WX. Several inbnds to msp were trying to get in on the meinz arrival. Medium large transport Y at FL350 was giving clearance to FL240. Medium large transport Y started to descend and medium large transport X was deviating further south and the C/a went off when the aircraft were about 50 seconds apart. The medium large transport Y was turned about 130 degrees left and expedited on the descent, the medium large transport X was turned left and climbed to approximately FL350.

Original NASA ASRS Text

Title: RADAR SEPARATION WAS LOST BETWEEN A DESCENDING ACFT AND AN ACFT LEVEL AT FL330.

Narrative: A LARGE AMOUNT OF WX AND TSTMS WERE IN OR NEAR THE SECTOR. MOST OR ALL ACFT WERE DEVIATING. AN MLG X WAS AN OVERFLT FROM SEA TO DTW AT FL330. HE WAS DEVIATING FOR THE WX. SEVERAL INBNDS TO MSP WERE TRYING TO GET IN ON THE MEINZ ARR. MLG Y AT FL350 WAS GIVING CLRNC TO FL240. MLG Y STARTED TO DSND AND MLG X WAS DEVIATING FURTHER S AND THE C/A WENT OFF WHEN THE ACFT WERE ABOUT 50 SECS APART. THE MLG Y WAS TURNED ABOUT 130 DEGS LEFT AND EXPEDITED ON THE DSNT, THE MLG X WAS TURNED LEFT AND CLBED TO APPROX FL350.

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.