X had less than standard separation from Y. System error.

Attributes
ACN	270531
Time
Date	199404
Day	Wed
Local Time Of Day	1801 To 2400
Place
Locale Reference	atc facility : vwv
State Reference	OH
Altitude	msl bound lower : 7000 msl bound upper : 7000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : tol tower : gdl
Operator	general aviation : personal
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Operating Under FAR Part	Part 91
Flight Phase	cruise other descent other
Route In Use	enroute : direct enroute airway : tol
Flight Plan	IFR
Aircraft 2
Make Model Name	Convair Undifferentiated or Other Model
Operating Under FAR Part	Part 91
Flight Phase	descent other
Route In Use	enroute : direct
Flight Plan	IFR
Person 1
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : private pilot : instrument
ASRS Report	270531
Person 2
Affiliation	Other
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	conflict : airborne less severe non adherence : published procedure non adherence : required legal separation other anomaly other
Independent Detector	other controllera
Resolutory Action	controller : issued new clearance flight crew : took evasive action other
Consequence	faa : investigated
Miss Distance	horizontal : 2500 vertical : 100
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error Inter Facility Coordination Failure

Narrative:

Controller told X he had a traffic conflict, and asked 'to immediately descend to 6000 ft - traffic at 5 O'clock position, talking to center.' I dove the plane, then looked behind me. I saw the convair Y descending too: I pulled up to climb and lose speed and passed behind Y. I think the problem was the twin was slow to lose altitude on his descent into detroit area. If I had stayed at my cruise altitude of 7000 ft, I would have been 1000 ft over his path.

Original NASA ASRS Text

Title: X HAD LTSS FROM Y. SYS ERROR.

Narrative: CTLR TOLD X HE HAD A TFC CONFLICT, AND ASKED 'TO IMMEDIATELY DSND TO 6000 FT - TFC AT 5 O'CLOCK POS, TALKING TO CTR.' I DOVE THE PLANE, THEN LOOKED BEHIND ME. I SAW THE CONVAIR Y DSNDING TOO: I PULLED UP TO CLB AND LOSE SPD AND PASSED BEHIND Y. I THINK THE PROB WAS THE TWIN WAS SLOW TO LOSE ALT ON HIS DSCNT INTO DETROIT AREA. IF I HAD STAYED AT MY CRUISE ALT OF 7000 FT, I WOULD HAVE BEEN 1000 FT OVER HIS PATH.

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.