Air carrier X had less than standard separation from air carrier Y. System error.

Attributes
ACN	138489
Time
Date	199003
Day	Sat
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : dxd
State Reference	MI
Altitude	msl bound lower : 25000 msl bound upper : 25000
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zob
Operator	common carrier : air carrier
Make Model Name	Widebody Transport
Flight Phase	cruise other
Route In Use	enroute : on vectors
Flight Plan	IFR
Aircraft 2
Operator	common carrier : air carrier
Make Model Name	Widebody Transport
Flight Phase	cruise other
Route In Use	enroute : on vectors
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	controller : radar
Qualification	controller : radar
ASRS Report	138489
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
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 : 1800 vertical : 0
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

I was vectoring aircraft for descent into detroit. I vectored air carrier X south and air carrier Y west to avoid my detroit traffic. These were at the same altitude. Air carrier Y was stopped at a lower than requested altitude for traffic. My intention was to climb air carrier X when clear of traffic. I got sidetracked and didn't get back in time to climb air carrier Y. When I noticed the situation I immediately turned both aircraft--climbed one and descended the other. The situation occurred because of increasing traffic and the temporary use of wrong altitude for direction of flight. Less use of wrong altitude for direction of flight and a smoothing out of the peaks and valleys of traffic would cause quite a few less errors. There are too many times when we are very slow and within a short time extremely busy. This at times can result in dangerous situations.

Original NASA ASRS Text

Title: ACR X HAD LESS THAN STANDARD SEPARATION FROM ACR Y. SYSTEM ERROR.

Narrative: I WAS VECTORING ACFT FOR DSCNT INTO DETROIT. I VECTORED ACR X S AND ACR Y W TO AVOID MY DETROIT TFC. THESE WERE AT THE SAME ALT. ACR Y WAS STOPPED AT A LOWER THAN REQUESTED ALT FOR TFC. MY INTENTION WAS TO CLB ACR X WHEN CLR OF TFC. I GOT SIDETRACKED AND DIDN'T GET BACK IN TIME TO CLB ACR Y. WHEN I NOTICED THE SITUATION I IMMEDIATELY TURNED BOTH ACFT--CLBED ONE AND DSNDED THE OTHER. THE SITUATION OCCURRED BECAUSE OF INCREASING TFC AND THE TEMPORARY USE OF WRONG ALT FOR DIRECTION OF FLT. LESS USE OF WRONG ALT FOR DIRECTION OF FLT AND A SMOOTHING OUT OF THE PEAKS AND VALLEYS OF TFC WOULD CAUSE QUITE A FEW LESS ERRORS. THERE ARE TOO MANY TIMES WHEN WE ARE VERY SLOW AND WITHIN A SHORT TIME EXTREMELY BUSY. THIS AT TIMES CAN RESULT IN DANGEROUS SITUATIONS.

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.